MSSD Synthesis by Fauzan Wassil

Written by:

Presented on:

Fauzan Wassil

08.01.2017

Master of Science in Sustainable Design

Completed on:

School of Architecture College of Fine Arts Carnegie Mellon University

08.10.2017

Acknowledgements I am honoured to present this thesis study to the world of architecture as a new shift on environmentally conscious design. It has been quite an experience, personally, to went through this study from the beginning of preliminary study until the last day of running the testbed experiment.

I would like to express my deepest gratitude towards my sponsor, LPDP Indonesia, for their financial and moral support during my study at Carnegie Mellon University. May prosper and wealth always find its place in my beloved home country, Indonesia My sincere apology to both of the advisors, Vivian Loftness and Dana Cupkova, for I was being a low-key student. I wish time was not pacing fast enough, one year is truly ephemeral for such a big process of learning the whole notion of sustainable design. Special thanks to both of you for I am a lost soul without your guidance To my fellow sustainable design program students, Shannon, Prerna and Yunlu, I would say thanks for being an acquaintance of mine. I might call you friends, in some extent of course, one day.

Lastly, to my family back home. Thanks for the support and prayers. May God Almighty, Allah SWT, gives us His shine of knowledge and science to better understand the universe.

Table of Contents 1.

2.

3.

Introduction ............................................................................................................................. 7 1.1

The Importance of Living faรงades .................................................................................... 7

1.2

Algae Movement .............................................................................................................. 8

1.3

Energy, Food, Shade and Carbon Potential.................................................................... 10

1.4

Hypothesis ...................................................................................................................... 11

1.5

Research Objectives and Deliverables ........................................................................... 12

The Precedents ...................................................................................................................... 13 2.1

Overview of Bioreactor Component .............................................................................. 13

2.2

Types of Encapsulation ................................................................................................... 13

2.2.1

Tubular System ....................................................................................................... 14

2.2.2

Panel System ........................................................................................................... 14

2.2.3

ETFE System ............................................................................................................ 15

2.3

Overview of Production Systems ................................................................................... 15

2.4

Quantification of Benefits .............................................................................................. 18

2.5

Case Studies.................................................................................................................... 20

2.5.1

BIQ House, Germany............................................................................................... 20

2.5.2

Urban Algae Canopy, Italy....................................................................................... 23

2.5.3

Urban Algae Folly, Portugal .................................................................................... 25

2.5.4

Urban Algae Folly, Italy ........................................................................................... 27

2.5.5

Supra-High Irradiance Algae Bioreactor, Czech Republic ....................................... 29

2.5.6

Algo Nomad, France................................................................................................ 31

2.5.7

Other Case Studies.................................................................................................. 32

The Testbed: AlgaeShade ...................................................................................................... 37

4.

5.

6.

3.1

Objectives ....................................................................................................................... 37

3.2

Construction Detail......................................................................................................... 37

3.3

Measurement Methods ................................................................................................. 40

3.4

Results ............................................................................................................................ 41

Integrating Algae Bioreactor into Faรงade Design .................................................................. 50 4.1

Flowchart Design Decision ............................................................................................. 50

4.2

Type of Surface ............................................................................................................... 51

4.3

Panel Frame System ....................................................................................................... 51

4.4

Dynamic System ............................................................................................................. 53

4.5

Pros and Cons ................................................................................................................. 55

4.6

Production Equipment ................................................................................................... 56

4.7

Algae Type ...................................................................................................................... 57

Conclusion ............................................................................................................................. 58 5.1

Key Benefits .................................................................................................................... 58

5.2

Key Guideline Points....................................................................................................... 58

5.3

Limitations and Concerns ............................................................................................... 59

Bibliography........................................................................................................................... 60

List of Figure, Equation and Table Figure 1 Ivy wall in Abbey Inn, England (top left), Vegetable Trellises by Chong Sinh Architects ...............7 Figure 2 BIQ House (Photographed by Author) .....................................................................................9 Figure 3 Dried Biomass (Source: Algenol.com) .................................................................................... 10 Figure 4 Wheat Grains from Algae (Source: algaevita.com) ................................................................. 11 Figure 5 Cultivation and production system........................................................................................ 13 Figure 6 Encapsulation types ............................................................................................................. 13 Figure 7 From Upper left to lower right: Horizontal Tube (Source: IGV Biotech), Vertical Tube, Helical (Source: Biosolarzentrum) and Pump (Source: Ohio State University) .................................................. 14 Figure 8 From left to right: Rectangular Panel (Scheffer et al), Triangular (source: ecologicstudio.com), Square (Kim et al) ............................................................................................................................. 15 Figure 9 Left: Accordion ETFE (Source: biopharmia.no), Right: Interwoven ETFE (source: ecologicstudio.com).......................................................................................................................... 15 Figure 10 Electric generation from biodiesel....................................................................................... 17 Figure 11 Biodiesel electric generator (source: directindustry.com) ..................................................... 17 Figure 12 Simple food processing of algae .......................................................................................... 18 Figure 13 BIQ House (Source: Author) ................................................................................................ 20 Figure 14 Panel mounting and support pipes (Lakenbrink, 2013) ......................................................... 21 Figure 15 Distribution Diagrams (Lakenbrink, 2013) ............................................................................ 21 Figure 16 Components Diagrams (Lakenbrink, 2013)........................................................................... 22 Figure 17 Biocanopy (Source: ecologicstudio.com).............................................................................. 23 Figure 18 Control tank (Source: ecologicstudio.com)........................................................................... 23 Figure 19 Panel Dimensions............................................................................................................... 24 Figure 20 Algae Harvesting in Process (Source: ecologicstudio.com) .................................................... 24 Figure 21 Algae Folly Portugal (Source: ecologicstudio.com)................................................................ 25 Figure 22 Screenshot of the algae app (Source: ecologicstudio.com).................................................... 25 Figure 23 Smart System Application (Source: ecologicstudio.com) ....................................................... 26 Figure 24 The structural system art (Source: ecologicstudio.com) ........................................................ 26 Figure 25 Urban Algae Folly (Source: ecologicstudio.com) ................................................................... 27 Figure 26 Spirulina biomass (Source: ecologicstudio.com) ................................................................... 27 Figure 27 Plan view of Urban Algae Folly (Source: ecologicstudio.com) ................................................ 28 Figure 28 Composition of Spirulina (Source: ecologicstudio.com) ........................................................ 28 Figure 29 Supra-High (Masojidek et al) ............................................................................................... 29 Figure 30 Algae bioreactor placement (Masojidek et al) ...................................................................... 29 Figure 31 Fresnel placement drawing (Masojidek et al) ....................................................................... 30 Figure 32 Fiberoptics and cultivation tube (Masojidek et al) ................................................................ 30 Figure 33 Algo Nomad (XTU Architects, 2015)..................................................................................... 31 Figure 34 Panel Prototyping (XTU Architects, 2015) ............................................................................ 31 Figure 35 Panel design (Kim, 2015) .................................................................................................... 32 Figure 36 Panel design (Tamburic et al, 2011)..................................................................................... 33 Figure 37 Final result (Tamburic et al, 2011) ....................................................................................... 33 Figure 38 Climate comparison (Slegers et al, 2010) ............................................................................. 34 Figure 39 Relation with vertical rows and tube distant (Slegers et al, 2010) .......................................... 34 Figure 40 Energy Production Comparison ........................................................................................... 36

Figure 41 Algaeparc Waterbed (www.kennislink.nl) ............................................................................ 36 Figure 42 Testbed Front Elevation...................................................................................................... 39 Figure 43 Connection details ............................................................................................................. 39 Figure 44 FLIR Usage Method ............................................................................................................ 40 Figure 45 From left to right: Newly hanged tubes and microalgae seed ................................................ 41 Figure 46 AlgaeShade second day ...................................................................................................... 41 Figure 47 AlgaeShade first week ........................................................................................................ 42 Figure 48 AlgaeShade final look ......................................................................................................... 42 Figure 49 FLIR Result chart ................................................................................................................ 43 Figure 50 Left: Surface with AlgaeShade, Right: Surface Without ......................................................... 44 Figure 51 Placement of the thermocouples, left: surface with AlgaeShade, middle: surface without AlgaeShade, right: on the tube .......................................................................................................... 44 Figure 52 HOBO data acquiring result ................................................................................................ 45 Figure 53 Temperature from sunrise to sunset ................................................................................... 45 Figure 54 Biomass acquirement methods and result ........................................................................... 46 Figure 55 Visualisation of benefits ..................................................................................................... 48 Figure 56 Control tank needed to be filtered ...................................................................................... 49 Figure 57 Design decision flowchart ................................................................................................... 50 Figure 58 Pros and Cons of panel frame system .................................................................................. 55 Figure 59 Pros and cons of dynamic system........................................................................................ 55 Figure 60 Production System ............................................................................................................. 56 Figure 61 Flocculation chamber on the basement of BIQ House .......................................................... 57 Figure 62 Algae Type......................................................................................................................... 57 Equation 1 Triglyceride (Parent Oil) ................................................................................................... 10 Equation 2 Benefits estimation .......................................................................................................... 47 Table 1 Comparison of some biodiesel sources (Chisti, 2007) ................................................................9 Table 2 Methods selection of production system steps (Slegers et al) .................................................. 16 Table 3 Possible combinations of methods in production steps (Slegers, et al) ..................................... 16 Table 4 Some of the microalgae production rate from Mata et al table ................................................ 18 Table 5 Quantifiable parameters and its units .................................................................................... 19 Table 6 BIQ House Properties ............................................................................................................ 20 Table 7 Urban Algae Canopy Properties ............................................................................................. 23 Table 8 Algae Folly Properties............................................................................................................ 25 Table 9 Urban Algae Folly Properties.................................................................................................. 27 Table 10 Supra-High properties ......................................................................................................... 29 Table 11 Algo Nomad properties ....................................................................................................... 31 Table 12 Components List ................................................................................................................. 37 Table 13 Specification of core components ........................................................................................ 38 Table 14 Specification of core components ........................................................................................ 38 Table 15 Measurement Parameters ................................................................................................... 40 Table 16 FLIR Result .......................................................................................................................... 43 Table 17 List of component price ....................................................................................................... 48

1. Introduction 1.1The Importance of Living faรงades Faรงade design can better integrate architecture with the environment by the consideration of living faรงade approaches. Living facades range from ivy covered walls, to extensive green canopies and terraces, to engineered green walls to algae bioreactors. These living facades are ecological machines that reduce carbon in the atmosphere and potentially provide food and/or energy, benefitting both the environment and people (Amir et al., 2011). Living facades adapt to local climate and seasons. They provide natural shading during the summer, natural humidification in dry climates, solar access during cold periods, carbon sequestration through photosynthesis, and the opportunity to produce visual quality, food and energy source (Loftness, 2017). The adaptability of living facades has changed the face of architecture in recent years, as seen on Figure 1 below.

Figure 1 Ivy wall in Abbey Inn, England (top left), Vegetable Trellises by Chong Sinh Architects in Vietnam (top right), Green wall house by Samyn and Partners in Brussels (bottom left) and Interstitial green space of fondation Cartier by Jean Nouvel (bottom right)

Ivy covered walls have defined the Ivy League Universities, contributing to their ability to function without air conditioning for hundreds of years. The Ivy cover provides less fluctuation and limited daily range of interior temperature and humidity (Sternberg et

al., 2011). It reduces diurnal temperature maxima on warmer days by keeping surfaces cooler. During winter time, it prevents the surface from excessive cooling at night and reduces any chance of below 0 0C temperature. Ivy covered walls are truly the first living facade which thrived for centuries.

Trellises and vertical gardens as shading devices have a long history. First massive application dates back to the Babylonian era where the hanging garden was a beacon of green natural design in the centre of the world. In many cases, vertical gardens provide local food source for the community Exterior Green walls as shading devices provide beauty and air purification potential (Charoenkit, S., Yiemwattana, S., 2016). By putting evergreen plants on the exterior facade, the carbon sequestered can reach up to 30.6 grams per square meter during summer. The number expected to go higher in better season such as spring or fall.

Green walls also proven to lower the surface temperature of building facades.

Interstitial green spaces are recently in trend after Jean Nouvel designed it as Fondation providing extra green space to act as a buffer. Interstitial green space makes room between facades more livable and green, not to mention improving visual quality as well as biophilic experience.

Finally, algae bioreactor faรงades - the latest frontier of living facades. It is deemed to be the most cutting edge living facade, with sophisticated technology to produce natural energy, food material and to sequester carbon.

The power of these living facades is in shading, carbon sequestration, food and energy production. Carbon sequestration is through photosynthesis, in which CO2 is used and O2 is produced. Leafing, flowering, and fruit producing plants may sequester up to 52.8 kilograms of carbon per hectare per year (Charoenkit, S. and Yiemwattana, S., 2017). There is an overwhelming amount to available roof and faรงade space in dense urban environments. Livin g facades offer these cities a new future.

1.2 Algae Movement Ever since the world has been looking for an alternative source of fuel, many researchers had come up with solutions such as corn oil, palm oil or even soybean oil. The idea of biodiesel has been going on from 50 years ago (Knothe et al., 1997) and even the technology to process living organisms into oil is not an entirely new science. However, biodiesel from those crops needs to grow in a humongous tract of land. For instance, soybean needs 594 hectares to produce 446 litres of oil per hectare and corn even needs 1540 hectares for a less number of oil. Because of that, biodiesel started to gain less popularity until a researcher from New Zealand pointed out the sensible reason why microalgae are the best source for biodiesel; it is twenty times more productive than the best vegetable oil producer oil palm (Chisti, 2007). Compared to other

common oil crop such as corn, soybean, canola and others, microalgae easily overthrown them by a difference of almost 100,000 Litre per hectare. The comparison can be seen in the following Table 1.

Table 1 Comparison of some biodiesel sources (Chisti, 2007)

Crop Corn Soybean Coconut Palm Microalgae (70% lipid)

Oil Yield (L/Ha) 172 446 2,689 5,950 136,900

Land Area Needed (Ha) 1540 594 99 45 2

Microalgae are unicellular organisms that use CO 2 and sunlight to produce biomass which can be potentially processed further into fuels, foods and bioactives (Metting and Pyne, 1986; Schwartz, 1990). Mainly it contains triglyceride as its main lipid chain that it is easy to convert into biofuel. With such huge advantage of producing a new form of fuel, several attempts have been made to try to supply buildings, the largest sector that consumes energy, with oil from microalgae. The latest and only attempt to actually put microalgae as a part of the building was done in 2012 by IBA Hamburg in Germany. They installed panels which commonly used by algae farmers to grow the biomass into the faรงade of a 5-storey residential building, as seen in Figure 2 below.

Figure 2 BIQ House (Photographed by Author)

As fascinating as it looks, the integration between the two systems might still be a dream of the future. The biomass is not converted into energy directly on site. All produced biomass is sent to an off-site processing system so the cost and energy expense of transportation might not yet justify the energy generated. The panel itself has a considerable amount of opaqueness therefore it is hard to substitute or complement a building fenestration design. Problems aside, the notion of implementing microalgae energy producing system in buildings is an innovation in the architecture world and bioscience. My research thesis is trying to outline and suggests

potentially better integration design ideas for microalgae systems in building enclosures and analyse its visual quality from the occupant perspective.

1.3 Energy, Food, Shade and Carbon Potential Microalgae are energy producing cell factories that convert carbon dioxide into triglycerides by using sunlight and nutrients such as nitrogen in water (Spolaore et al., 2006). Triglyceride is a three-fatty acid molecules which esterified with glycerol, the chemical structure can be seen in Equation 1 below.

Equation 1 Triglyceride (Parent Oil)

Triglyceride is the gold that microalgae produces overtime and with the perfect combination of sunlight, carbon dioxide and nutrients, the amount of triglyceride produced can be b oosted significantly due to photosynthesis process. That is why the growing or cultivation system of an algae bioreactor is crucial towards better productivity rate. The triglyceride is visible in naked eye as a form of lipid contained in such mulch found inside the algae solution. By putting the microalgae inside a water full of nutrients and carbon dioxide, an algae solution is being made.

The algae solution then exposed into sunlight or any of its substitute so the microalgae can start the photosynthesis to produce what commonly called biomass. Biomass is a green mulch that contains biolipid or triglycerides and dry mass. Figure 3 below shows a dried biomass where it is ready to be processed further as triglycerides or food produce.

Figure 3 Dried Biomass (Source: Algenol.com)

To grow these microalgae in a human controlled environment, there would be a set of equipments called the algae bioreactor. The bioreactor system is divided into three subsystems; the cultivation system, energy producing system and food producing system. While energy and food production system is not necessarily connected to the cultivation system, this study will try to bring some of the systems together in one roof or site. The cultivation system, will be

explained further in Subchapter 3.2, is the most crucial system in harvesting the algae biomass.

It is the container and producer of biomass. The energy and food producing system are the processing systems which extracts biomass into energy and food, will be elaborated further in Subchapter 3.3 and 3.4.

As the big topic of the research study, energy productivity of algae bioreactor system will be explored further by getting familiar with systems which are existing in various scales. It is a basic understanding that algae provide the world with energy source such as methane (Spolaore et al., 2006) and biohydrogen (Ghirardi et al., 2000). This study will try to go deeper into the various systems of processing algae into fuel and electricity and try to understa nd their advantages of being implemented in a building wide system.

Food from algae has been explored from quite a while ago, dating back to 1960s where Japan started the first Chlorella industrial scale production for food. 20 years after that, production facilities started to spread across Asia, United States, Israel and Australia (Enzing, Ploeg, Barbosa, & Sijtsma, 2014). Now 37 years from there, various new technology has been invented therefore the study needs to explore further advanced technology and try to find the most suitable one to be implemented inside a building or an annex facility. The study will also explore the kind of existing algae food market in United States, such as AlgaVia Lipid-Rich Algae Wheat in Figure 4.

Figure 4 Wheat Grains from Algae (Source: algaevita.com)

1.4 Hypothesis Algae bioreactor can be integrated into building enclosures with design quality to provide shade, a clean energy source, food production, and carbon sequestration. Here are the sub hypotheses; Algae bioreactors provide quality (aesthetics and performance) faรงade elements for buildings Algae food producing system offers a new form of urban agriculture that can feed the occupants directly Algae bioreactor offers electricity generation on-site with integration in building systems

Carbon cycle in the algae system offers non-emissivity, clean and potential sequestration The aim of study is to explore the possibilities for and suggest better integration of algae bioreactor system with building enclosure to appeal the interest building owners, designers, architects, engineers, scientists and the public that microalgae holds the possibility of becoming future faรงade system for various building typologies. Especially in constant sun radiation climates such as Indonesia, the productivity value will presumably more stable and progressive whereas cold climate will not. The idea of turning excess sunlight and radiation into energy while also providing comfort for building occupants is something that need s to be achieved.

1.5 Research Objectives and Deliverables The research intends to meet the following objectives: To establish key understanding of algae bioreactor system as an energy generating, food producing and carbon sequestering system To study and analyse strategies from existing built building-related case studies and non-building related research studies To formulate design integrations of algae bioreactor as a faรงade element and its supporting system To explore the production capability in a test bed To illustrate design suggestions for building types in climates to showcase how the design factors implemented in real building design

2. The Precedents 2.1 Overview of Bioreactor Component The cultivation system is responsible in growing algae and harvesting it. It comprises of encapsulation, control tank and supporting equipment for extraction and circulation.

Production system is the processing module which generates biofuel or any desired products.

Can be located on-site or offsite.

Figure 5 Cultivation and production system

2.2 Types of Encapsulation In algae farms, there are two types of cultivation system; the first one is open loop and the second one is a closed loop. Open loop allows the algae solution to interact with open air, commonly seen in ponds system, whereas closed loop system contains the solution in a form of encapsulation free from external intervention or disruption. There are numerous types of closed loop system, but the most common one used in algae cultivation facilities are;

Figure 6 Encapsulation types

2.2.1 Tubular System The algae solution is contained inside a closed tube stacks that can run vertically, horizontally or helix. It uses pump to make the solution flow constantly so an exchange of heat, sunlight and nutrients are occurring inside the loop system. There are four types of tubular system, which are Horizontal Tube (stacked vertically), Vertical Tube (stacked horizontally), Helical (stacked vertically as circles) and Pump Tube. The images of these types can be seen in Figure 7 below.

Figure 7 From Upper left to lower right: Horizontal Tube (Source: IGV Biotech), Vertical Tube, Helical (Source: Biosolarzentrum) and Pump (Source: Ohio State University)

2.2.2 Panel System Panel system contains the algae solution inside a thin glass panel. This system was first implemented in the BIQ House building. The major difference between panel and tubular is that panel system commonly has larger surface contact area with the algae solution. In terms of solution and nutrient exchange, it would happen inside the panel or outside in a control unit.

Since the thickness is relatively small, the visible transmittance of this type is lower than the tube system but again, the algae type also has a great impact towards colour and visibility.

There are many types of this system such as rectangular panel, triangular panel and hollowed -dimensional form will take. Figure 8 shows some of the types that exist.

Figure 8 From left to right: Rectangular Panel (Scheffer et al), Triangular (source: ecologicstudio.com), Square (Kim et al)

2.2.3 ETFE System ETFE is short for Ethylene Tetrafluoroethylene, durable plastic-like material which been commonly used as building enclosures. The flexibility of ETFE material makes it vary by form.

There are several types and samples of ETFE system, such as the accordion system and the layered system. Many algae farmers prefer ETFE over tubes due to its flexibility and compatibility with various equipment such as plastic hoses, glass framing and steel framing. In terms of enclosure, usually ETFE would be design in combination with flat panels where the exterior encapsulation being steel rim. Thus, giving the closed loop system inside a good pressure to maintain preferable algae growth within the system. Some of the following images show standalone ETFE systems in algae farm.

Figure 9 Left: Accordion ETFE (Source: biopharmia.no), Right: Interwoven ETFE (source: ecologicstudio.com)

2.3 Overview of Production Systems The cultivation system is just the first step of growing the algae, the next process is to harvest it and further process it into energy or food. Before getting into the complex flow process of algae production system, the cultivation system must be supported by supporting equipment to collect the biomass and further transport it to the production system. There are 5 steps in a process of algae biomass cultivation in order to be converted as biodiesel; harvesting, dewatering, disruption, extraction and lipid conversion (Slegers et al., 2011). There is various selection of methods for each step, shown below in Table 2.

Table 2 Methods selection of production system steps (Slegers et al)

Harvesting Centrifugation Pressure filtration Vacuum filtration Cross flow filtration Ultrasound sedimentation Chemical flocculation Biological flocculation Autoflocculation Dissolved air flotation Suspended air flotation Electrolytic flotation

Dewatering Centrifugation Pressure filtration Vacuum filtration Drying Steam evaporation

Disruption Bead milling Homogenisation Ultrasonic Supersonic wave Pulsed electric Acid treatment Enzymatic cell French press

Extraction Traditional Mixed Solvent Supercritical CO2 Ionic liquids Two-phase Switchable Surfactants

Conversion Acid catalyst Alkali catalyst Hetero catalyst Enzymatic

However, in terms of choosing the methods, process engineers usually run a stepwise approach to formulate the best performance for the whole system. Early decision may affect the process down the road if the method selection is nonoptimal. Therefore, Brentner et al recognised the best possible combinations of processing methods shown in the flowchart shown in table 3 below.

Table 3 Possible combinations of methods in production steps (Slegers, et al)

This flowchart helps optimise process conditions with outcomes such as increased biodiesel yield and Net Energy Ratio (NER) values. Most of the equipments are large heavy, hot and sophisticated. Therefore, in producing biodiesel on site from algae bioreactor, a thorough design and planning should carefully consider the risks. The BIQ House project, for instance, deliver their biomass from the cultivation system to an off-site processing facility and retrieve it back in a form of biodiesel. By sending off the biomass, they minimised space usage for equipment and avoided permit regulation of having heavy duty equipment in a residential building. There are a lot of studies of how to efficiently convert biodiesel to electricity (Knothe,

et al, 2015) and most of them involves combustion chamber or boiler. The biodiesel as fuel source will be pressurised and burn to move turbines which connected directly to the mechanical electrical generator. There are various turbines such as gas turbines, steam turbines, compression-ignition engines, combined cycle, and others (biodiesel.org, 2007). The process can be seen in the flowchart in Figure 10 below.

Figure 10 Electric generation from biodiesel

Nowadays, biofuel generators are optimised and available for household to purchase. Most of them look like usual diesel generators that can be found in stores. Since these generators are easy to find, less noisy, completely safe and in a size of a storage chest, it is the solution which many algae farms are likely to resort to. Figure 11 below shows the form of biodiesel generator.

Figure 11 Biodiesel electric generator (source: directindustry.com)

However, biodiesel is not the only outcome which algae bioreactor may produce. The dry biomass can be furthered processed into food material as well. Algae is a well-known source of almost as much as half portion beef rib. In harvesting the liquid biomass, the nutrients and solutions must be cleansed with water to get rid any impurities of the biomass. It is also an option to put it into centrifugal disc machine to break the cellulose wall for optimum result but the process is not mandatory. Once the biomass is pure, it will be dried in a paper wrap until its texture become much like milk powder. Algae powder is ready to serve. The process diagram can be seen below.

Figure 12 Simple food processing of algae

Facilities like Algavia have different approach on food processing, depends on what kind of food to be produced. Since they focused on bread based product, their algae is fermented with sugar inputs from beet, cane and other source of natural glucose to achieve sweet algae powder. The powder, combined with yeast, can be used as wheat substitute.

2.4 Quantification of Benefits As a performance indicator, algae bioreactor has several benefits which quantifiable. In determining productivity rate of algae bioreactor, the universal metric is gram of biomass.

Although sometimes volume of liquid biomass is also acceptable, direct conversion from gram to other means of quantity is much simpler. From biomass, the quantities which can be predicted and measured are electricity in kilowatt-hour and food material in grams. The quantification will be divided per square metre of algae bioreactor facade cover. Aside from energy and food, there is also carbon sequestration value. Biomass production may have a correlation with the amount of carbon, but there is no cause relation between both of them.

The productivity rate of a closed algae bioreactor system is majorly affected by climate (Slegers et al, 2011), algae type (Mata et al., 2010) and the encapsulation (Hemming et al, 2012). Other parameters such as nutrient composition or construction detail play a less significant roll (Qiu, 2014). To predict the production rate of algae bioreactor system, Mata et al have published a comprehensive table for common algae types and its biomass productivity. Some of the microalgae from the table can be seen below.

Table 4 Some of the microalgae production rate from Mata et al table

Microalgae Species Chlorella vulgaris Spirulina maxima Chlorella sp.

Phaeodactylum tricornutum Chlorella sorokiniana Haematococcus pluvialis Nannochloropsis sp.

Dunnaliella salina Pavlova salina

Lipid Content (%dry weight) 50-58% 4-9% 10-48% 18-57% 19-22% 25% 12-53% 6-25% 30.9%

Lipid Productivity (mg/L/day) 11.2-40.0 42.1 44.8 44.7 37.6-90.0 116.0 49.4

Volumetric Biomass (g/L/day) 0.02-0.20 0.21-0.28 0.02-2.5 0.003-1.9 0.23-1.47 0.05-0.06 0.17-1.43 0.22-0.34 0.16

Areal Biomass (g/m2/day) 0.57-0.96 25 0.57-0.95 2.4-2.1 20.89 10.2-36.4 1.9-5.3 1.6-3.5/20-38 -

Biomass and Electricity The biomass productivity rate is the basis for electricity calculation. In order to quantify how much watt-hour a bioreactor produce, the amount of biomass per day has to be acquired. After that, the unit has to be converted from gram per sqm per day into ton per sqm per day. Since 1 ton of biofuel equals to 0.86 tonnes of oil (toe) and 1 toe is equal to 11.36 MWh, 1 ton of biomass can produce 9.9 MWh. The result can be also extrapolated into an annual energy production, but it will be peak instead of average. Usually in final annual energy production, the result will be further decreased by 30% due to low-peak sun intensity, energy loss in pumps, transport, and others (Lakenbrink, 2013).

Food and Protein To calculate food benefit, algae powder will mostly stay the same amount before and after fermentation, if there is any fermentation process. So, it is safe to say that the amount of biomass produced is equal to the amount of food, but the protein substance will be different. In quantifying food, it is better to calculate the amount of protein contained instead of just dry weight. By using the table published by Mata et al, the percentage of lipid is equal to the percentage of protein (Mata et al., 2010).

Carbon and Oxygen The average microalgae can sequester 4.5 litres of carbon from 6.2 litres of algae biomass volume (Kim, 2013). It means that algae bioreactor can absorb CO2 as much as 72.6% of its total biomass production per litre. Since the amount of O2 should be half than CO2 absorbed, the oxygen production of algae bioreactor is equal to 36.3% of its total volume of biomass.

Shading Since it is hard to quantify shading capabilities, algae bioreactor has a potential of lowering the temperature of external surface. It can be measured through the difference between average temperature on two surface; the surface with algae bioreactor and without. The design of facade bioreactor could vary and therefore shading coefficient and visible transmittance would dependent to its design. The summary table every quantifiable benefit in algae bioreactor can be seen on the following Table 5.

Table 5 Quantifiable parameters and its units

Benefit Biomass Electricity Food Carbon Oxygen Shading

Unit gram/sqm/day kWh/sqm/year gram/sqm/day kg or litre kg or litre

Notes Dry weight gram -> ton -> toe -> kWh Protein amount, % of dry weight Photosynthesis formula Photosynthesis formula Difference between surface temp with algae facade and without

2.5 Case Studies 2.5.1 BIQ House, Germany

Figure 13 BIQ House (Source: Author) Table 6 BIQ House Properties

Climate Algae Type Type of Encapsulation Panel Area Orientation Energy Production Avg. Biomass Production CO2 Sequestered Local Equipment

5A Chlorella Vulgaris Square Flat Panel 243.81 sqm South and West 50 kWh/sqm/yr 14.99 g/sqm/day

Unknown Internal cleaner, inlet air blower, overflow tubes, tubing groups, algae separator Building Heat exchanger, Equipment Geothermal Heat Storage The BIQ House in Hamburg, Germany is undoubtedly the most significant example of a fully integrated algae bioreactor facade. It is the only building in the world

which succeeded in implementing algae bioreactor as a building enclosure and it has been running since 2012. The BIQ House is a 5-storey multi-family housing with 2 approximately 1,600 m gross floor area.

The BIQ House costs 5 million euro and was funded by the Hamburg Climate Protection Concept. The distinct faรงade was designed by architecture firm Splitterwerk and developed further by ARUP Deutschland. It has algae bioreactor facades installed on the southeast and southwest face of the building, designed to produce biomass and passive solar heat collection. Since the glass panels are installed on the opaque part of the faรงade, it holds no visual properties to the occupants. The size of the panels is 70 cm wide, 270 cm high and 8cm thick, arranged in a group of 2 to 5 with a total of 129 panels. The panels are mounted in steel frames with embedded piping throughout each panel as seen in Figure 14 below.

Figure 14 Panel mounting and support pipes (Lakenbrink, 2013)

Figure 14 above shows how the nutrients, CO2 and algae circulated inside the panel groups.

Basically, the panel contains algae solution and regularly blown CO2, with overflow tubes at the top. The tubes on the bottom of the panel supply nutrients and water. The biomass produced inside the panel will automatically drained to the bottom since it has heavier mass compared to the medium. Using an extraction pipe, the biomass is captured and further thrusted into conversion equipment. There is also an internal cleaner device that cleans the inside of the panel regularly so biomass leftovers can be flushed into the extraction tubes. The pipe flow diagram can be seen in Figure 15 below.

Figure 15 Distribution Diagrams (Lakenbrink, 2013)

While this process happened, the heat from the panels is flown through heat exchanger. The heat exchanger later stores all the heat into boreholes geothermal units to provide heating for the buildings when necessary. Ideally, the biomass extracted is processed within an on-site biodiesel or food machines but at BIQ House, they sent the dried biomass into an external facility. The result will be methane where they will put it into combustion chamber to produce electricity. The integration between BIQ House algae bioreactor facade and its building equipments can be seen in diagram below.

Figure 16 Components Diagrams (Lakenbrink, 2013)

There is no food productivity measured, although Lakenbrink did mention the possibility of sending it into a food processing facility. After a couple of years running, they claimed that the productivity rate of the whole instalment is approximately 14.99 grams per square metre per day or equal to 900 kg per year. The converted biomass is then converted to biomethane, as a biofuel source, in an annex facility off-site. The total 200 m2 of algae bioreactor manages to produce roughly 612 m3 of methane per year. The energy contained inside such amount of methane is predicted to be 6,487 kWh per year. With consideration of energy loss because auxiliary power, transportation, pump and others, there is 30% reduction expected. Therefore, the total net energy generated will be 4,541 kWh per year. The average usage of electricity in one apartment unit of BIQ House is approximately 3,500 kWh per year, it means that the algae bioreactor can only fully supply one out of 15 apartments. However, the heat generated from the bioreactors can reach up into 6,000 kWh so the rest of the apartment unit can still receive the benefit.

2.5.2 Urban Algae Canopy, Italy

Figure 17 Biocanopy (Source: ecologicstudio.com) Table 7 Urban Algae Canopy Properties

Climate Algae Type Type of Encapsulation Panel Area Orientation Energy Production Avg. Biomass Production CO2 Sequestered Local Equipment

3C Unknown Triangle Flat Panel 8.95 sqm No orientation 54.78 kWh/sqm/yr 16.85 kg/sqm/day

12 kg /day Sensor biomass collector This 1:1 scale mock-up was exhibited in Milan EXPO 2015 and was designed by EcoLogic Studio. They claimed it to be the -digital canopy to integrate micro algal cultures and digital cultivation on a distinct architectural system. The design itself was a combination of flat panel system and ETFC system, making it one of a kind in using hybrid type of encapsulation. It consists of 3 layers ETFC within a flat

cladding system. A special CNC welding was used to control the cushions under stress and the algal fluid dynamic behaviour. One of the key feature of this mock-up is that the flows of water, CO2 and algae are regulated to adjust weather patterns and visitor movements. Logically, if the sun intensity increases, photosynthesis productivity also increases thus making the biomass denser and thicker. This causes the panel to become more opaque so it provides more shading. The presence of visitor also triggers electro valves which alter the algal flow rate within the whole system.

Figure 18 Control tank (Source: ecologicstudio.com)

Figure 19 Panel Dimensions

Figure 19 square metre of surface area and there is another panel which shares similar surface area. The two remaining panels, of a total of 4, have roughly 2.8 sqm and 2.6 sqm which makes the total surface area of the bioreactor into 8.9 sqm. The total 4 panels are connected individually to the control tank by using transparent flexible hoses. The microalgae solution is pumped from the control tank to individual panels and then the solution flows downward due to gravitational pulls. While the panel seemed to be just flat, the ETFC inside is actually designed with certain tilting angle so the solution is able to flow seamlessly. Figure 20 below shows how the internal design of the ETFC.

Figure 20 Algae Harvesting in Process (Source: ecologicstudio.com)

It has predicted that the algae canopy bioreactor can produce up to 150 kg biomass per day with 60% lipid content (ecologicstudio, 2015). If it were to measure the biomass per area of surface, the number would be 150 kg divided by 8.9 sqm, which is equal to 16.85 kg/sqm per day. This result is actually quite staggering, since the previous precedent, the BIQ House, has managed to only produce 14.99 grams/sqm per day. The difference in algae type might be the defining factor for this case, although it is still remained unknown what type of algae that ecologicstudio used. The bioreactor will also generate oxygen equivalent of 4 hectares of woodland and since photosynthesis uses carbon twice as much as it generates oxygen, the amount of carbon sequestered is equal to 8 hectares of woodland.

2.5.3 Urban Algae Folly, Portugal

Figure 21 Algae Folly Portugal (Source: ecologicstudio.com) Table 8 Algae Folly Properties

Climate Algae Type Encapsulation Panel Area Orientation Energy Production Avg. Biomass Pro CO2 Sequestered Local Equipment

3C Chlorella vulgaris Triangle Flat Panel 10.15 sqm All 19.3 kWh/sqm/yr

as seen on Figure 22 below. It can read the algae solution flow rate on any desired node valve in the instalment.

3.43g/sqm/day

1.5 kg /day Electro valve, occupancy sensor, The latest instalment by ecoLogicStudio, located in the town of Braga, Portugal. It was placed in Praca da Republica to showcase the beautiful design of an algae pavilion. This newest prototype was one of long research on integrating urban agriculture with bio-digital system. Still using ETFE as its main cushion for the panels, ecoLogicStudio used a little addition of smart sensors in the system. All the valves at the end of every hose are readable through a specifically designed mobile app,

Figure 22 Screenshot of the algae app (Source: ecologicstudio.com)

The whole instalment was in a triangular site area of 17.6 sqm with total of 9 individual panels placed on a rather expressively designed pedestal. The panels had connected each other with special CNC welding technique and were arranged aesthetically facing upwards with miniscule tilting angle here and there. The 9 panels consist of 3 different type of panels (Fig 23).

Figure 23 Smart System Application (Source: ecologicstudio.com)

Panel A, B and C has an area of 1.1 sqm, 0.7 sqm and 1.6 sqm respectively. There are three panels each type so the total bioreactor surface area equals to 10.2 sqm. The panels are supported by structural frame which designed to mimic the Figure 24 below. Each panel has individual hose to connect them with the control tank. The inlet and outlet hoses for each panel are equipped with control system to automatically reduce or increase flow rate based on occupancy sensor located nearby the control tank. The electro valve and occupancy sensor is wired to a data box at the top of the control tank to centralised the data before transmitting it through wireless connection. The data box also monitors the amount of biomass generated inside the control tank. ecoLogicStudio has reported that the algae bioreactor produced 35 grams of biomass per day. With 10.2 sqm of total surface area, the productivity rate of Urban Algae Folly is 3.43 grams/sqm per day. The result is considerably normal since Chlorella vulgaris, despite of its tenacity on thriving in any kind of condition, has relatively low compared to other Chlorella. This instalment is also predicted to absorb 1.5 kg of CO2 per day and generates 750 g of oxygen daily.

Figure 24 The structural system art (Source: ecologicstudio.com)

2.5.4 Urban Algae Folly, Italy

Figure 25 Urban Algae Folly (Source: ecologicstudio.com) Table 9 Urban Algae Folly Properties

Climate Algae Type Encapsulation Panel Area Orientation Energy Production Avg. Biomass Pro CO2 Sequestered Local Equipment

3C Spirulina Triangle Flat Panel 23.2 sqm All 66.2 kWh/sqm/yr

presence. They claimed it to be the first biodigital example of architecture. The algae type is Spirulina platensis, known for its resiliency and thick biomass, as seen on the Figure 26 below.

21.3 g/sqm/day

4 kg /day Biomass Sensor, Digital Panel Interface Still a project by ecoLogicStudio, this one was located on the same spot as Urban gate centrepiece where it welcomed the visitors. The folly is occupying an area of 9.5 m by 9 m and designed to mimic a tree-like shelter. The panel consists of ETFE cushion with CNC welding as the connections.

EcoLogicStudio used the same electro valve and occupancy sensor to automate the flow rate according to sun intensity and visitor

Figure 26 Spirulina biomass (Source: ecologicstudio.com)

There are in total 27 individual panels with various tilting angle, 17 of them are more vertical whereas the rest are facing mostly upwards. Each panel has two hoses for microalgae inlet and outlet which connects the panel to the control tank, submerged below the ground. The 27 panels consist of three type of panels, as seen on Figure 27.

Figure 27 Plan view of Urban Algae Folly (Source: ecologicstudio.com)

The most vertical panels are 8 panels, each has an area of 1.2 sqm, the vertical smaller ones are each 0.4 sqm with a total of 9 panels and the most horizontals are 10 panels with 1 sqm of area each. This makes the total bioreactor surface area into 23.2 sqm, the biggest area which ecoLogicStudio had covered so far. It has been reported that the number of Spirulina produced each day is equal to the amount of protein contained inside a 2-kg meat. Since in an ounce of meat there is 7 grams of protein and 2 kg is equal to 70 ounces, the total biomass productivity is predicted to be 70 ounces multiplied 7 grams which equals to 493.5 grams daily. The total productivity rate will be 493.5 grams divided the total square metres, 23.2 sqm, which equals to 21.3 grams per sqm per day. Such result proves to be staggering, mostly due to the algae type and prefect sun balance in Milan. The design of Urban Algae Folly also counts as one of the main contributor to its productivity rate, as the large portion of the whole 27 panels are facing upwards. The folly has also been reported to sequestered 4 kg equivalent of CO 2 per day or as much as 25 urban trees would sequester the same amount. Spirulina platensis is one of the microalgae type which has rich composition of carbohydrates, fat, protein, vitamins, calcium and iron, as seen on Figure 28 below.

Figure 28 Composition of Spirulina (Source: ecologicstudio.com)

2.5.5 Supra-High Irradiance Algae Bioreactor, Czech Republic

Figure 29 Supra-High (Masojidek et al) Table 10 Supra-High properties

Climate Algae Type Encapsulation Panel Area Orientation Energy Production Avg. Biomass Pro CO2 Sequestered Local Equipment

6A Spirulina platensis Tubular Panel 9 sqm South 98.55 kWh/sqm/yr 32 g/sqm/day

Unknown Fresnel lens,loop reactor, degasser, light supply, pump, CO2 supply, control unit and heat exchanger The bioreactor was set-up at the Academic and University Centre of Nove Hrady, Czech Republic. It was designed with sunlight concentrators to optimise biomass yield.

The bioreactor consisted of 6 vertically stacked tubes with inner diameter of 48 cm and the distance between them was 37 cm.

The 6 tubes were connected with U-pipes at

their ends to finally form a 24-m loop, placed on a laboratory skylight with southern exposure. The skylight was covered by insulating double glazing with linear fresnel lenses. The total area of skylight which covered by the bioreactor is roughly 9 sqm (fig x). The skylight is a part of the laboratory roof and has a tilting angle of 400.

Figure 30 Algae bioreactor placement (Masojidek et al)

The distinctive feature of this supra-high irradiance was the fresnel lenses (fig x) used as a solar concentrator. It consists of double lenses Solarglass system made by Glaverbel Czech Ltd.

Figure 31 Fresnel placement drawing (Masojidek et al)

Figure 31 above shows how the lenses are placed in line with the centre of the cultivation tubes so that its focus hits the tubes perfectly right in the middle. The distance between the lenses and the tubes is 50 cm. The maximum irradiance which these lenses generated is between 1.5 1.8 mmol photon per sqm per second. The irradiance is further condensed to the tubes and reached numbers higher than 2 mmol photon per sqm per second. They were testing it during sunny days between March and September 2002 and the peak irradiance that they can get was 7 mmol photon per sqm per second. The high irradiance made them realise that Spirulina platensis, the algae type being used, has an internal mechanism to deal with sun intensity. It develops a high level of non-photochemical quenching. Aside from fresnel, the bioreactor also used light sensors, pH meter and oxygen meter. They really want to keep track of how the lenses are affecting the bioreactor. Photosynthetically active radiation or PAR was measured by a quantum sensor coupled to a light meter. The pH/0xi340i were used to monitor pH and oxygen concentration. Figure 32 shows how the equipments are connected with the bioreactor system. By using these lenses, Masojidek et al had reported 30% increase on biomass productivity compared to ordinary tubular bioreactor made by Torzillo et al in 1991. In the end, the biomass production rate was as high as 32.5 grams per day, which is a high value since it was September. The high irradiance made them realise that Spirulina platensis, the algae type being used, has an internal mechanism to deal with sun intensity. It develops a high level of non-photochemical quenching to relieve itself under stressful environment.

Figure 32 Fiberoptics and cultivation tube (Masojidek et al)

2.5.6 Algo Nomad, France

Figure 33 Algo Nomad (XTU Architects, 2015)

the algae facade reportedly managed to produce 3 grams of biomass per sqm per Climate 4A day. However, there are no published data Algae Type Unpublished about what kind of algae used so predicting Encapsulation Square Flat Panel the exact energy production would be tricky Panel Area 12 sqm and might lead to a misleading result.

Orientation South-east Nevertheless, the facade concept will be Energy 9.3 kWh/sqm/yr incorporated in 2017 for a building in Production Champs sur Marne called Center Scientifique Avg. Biomass Pro 3 g/sqm/day CO2 Sequestered Unknown et Technique du Bâtiment (CSTB). There will Local Equipment Steel framing be 16 algae bioreactor panels install in the support, submerged facade panels with total area of 48 sqm. The control tank panel was installed per 2016 but the AlgoNomad is an exhibited pavilion located microalgae solution has not been in Paris City Hall Square. It is a public urban intervention to remind the citizen of Paris about COP21 conference. The pavilion was designed by XTU Architects, who has done research on algae facade for almost 6 years.

The project is a collective effort of various institution such as GEPEA, Viry, Algosource and others. The glass facade is developed by Viry Groupe Fayat and the algae panel prototype was researched by University of Figure 34 Panel Prototyping (XTU Architects, 2015) Nantes. The pavilion contains 4 active algae bioreactors, with dimension of 3 m by 1 m,

Table 11 Algo Nomad properties

2.5.7 Other Case Studies While there are only limited case studies on building related algae bioreactor, the number of studies on algae production is myriad. In this subchapter, some of the case studies deemed to be relevant to building applications will be elaborated further to extract useful insights and revelations which the following researches might potentially have.

Feasibility Study of an Algae Façade System, Kyoung-Hee Kim, 2013 A researcher from University of North Carolina has developed a flat panel design for algae bioreactor façade. The design was concerned more on system, materials, fabrication, energy consumption and end-of-product-life. Therefore, there was no algae biomass productivity measured or reported except from hypothetical calculations. The panel was made by acrylic, it is 12 feet tall and 5 feet wide and it has a thickness of ½ inch. One thing which addressed very well in the panel design is the realisation that algae façade does not provide decent daylighting due to its dense colour. So, the panel design allocates translucent oval surfaces on the façade for optimum light penetration, as seen on Figure 35 below.

Figure 35 Panel design (Kim, 2015)

to assess daylighting effect on different glass film. By using HDR photogrammetric techniques to evaluate daylight performance of clear translucent film and red translucent film. Aside from daylighting, the study also assessed thermal performance façade. The thermography test results show that the -factor is comparable to a low-e coated insulated glass unit or IGU. In real application, the thermal mass of algae solution will potentially decrease the U-value so it will have better thermal performance compared to IGU. The panel fabrication process also tested stress and pressure to analyse its sturdiness as a building façade. At the end, the study calculates how much productivity and benefits the panel might potentially have. By using Mata et al table, it is predicted that one panel will produce as much as 3 grams of Chlorella biomass per day and 1 kg of CO2 sequestered per day. Applied to a 42-storey building as a case study, there will be in total of 1100 gallons of biomass produced.

Flat-plate photo bioreactor system for algal hydrogen production, Tamburic et al, 2011 A group of researchers from Imperial College of Science London has developed and fabricated a flat panel prototype for algae bioreactor. The study was focusing on hydrogen production in pursue of better H2. The panel is designed to be square with dual compartment inside and an array of LED on the back, as seen on the following diagram.

Figure 36 Panel design (Tamburic et al, 2011)

The final dimension of the design is 25 cm by 25 cm with a thickness of 6.5 mm. It is considerably thick due to the LED array placed on the back of the panel. Since the study is focusing on bioreactor design, it uses LED instead of sunlight to enhance productivity. It was not meant to be a building faรงade prototype but the study addressed one design factor which potentially benefit flat panel design. The volume-to-surface ratio has to be in equilibrium and by using flat double compartment, they managed to achieve such staggering results. The final built bioreactors can be seen on pictures below.

Figure 37 Final result (Tamburic et al, 2011)

Productivity comparison between two climates, Slegers et al, 2010 A group of researchers from University of Wageningen conducted several simulations to formulate best design parameters for algae tubular bioreactor. Using MatLab software, they model a scenario of vertical tubes bioreactor placed in two different climates, The Netherlands (5A) and Algiers (3A). The biomass growth model was developed according to Geider model (Geider et al., 2010), by tracking light data inside the tubes and correlating them to reactor geometry and production location. The results would be light input on reactor surface, light loss, light gradients and the growth rate. The growth rate then used as a multiplier in relation to algae characteristics to obtain production of biomass. For the simulation, the algae species used is P. tricornutum with concentration from 0.2-12 kg m3. The distance between stack tubes is 1 cm and the tube diameters are 6 cm. The number of vertically stacked tubes is 9 and each tubes has refraction value of 1.510. The simulation result can be seen on diagram below.

Figure 38 Climate comparison (Slegers et al, 2010)

The result clearly shown that climate with warmer temperature and higher solar irradiance will boost biomass productivity and relatively constant growth during cold season whereas in cold climate the biomass growth seems to be more inconsistent. Even in some season it shows growth deficiency. It means that vertical bioreactor will be much suitable for climate with stable solar irradiance such as climate 1A to 3A. The simulation also identifies the effect of tube diameter and distance between stacked tubes, as seen in chart below.

Figure 39 Relation with vertical rows and tube distant (Slegers et al, 2010)

Cli 5A 3C 3C 3C 6A 4A 5A 3B 4B 3A 5A 5A 5A 5A 3B 1A 1A 3C 2B

Project

BIQ House, Germany

Biocanopy, Italy

Algae Folly 1, Portugal

Urban Algae Folly, Italy

Supra-High, Czech Rep

Algo Nomad, France

Algaeparc, Netherlands

Cellana, San Diego

Accordion, Arizona

Lu et al, China

Algae Turbo, Germany

Biosolarzentrum, Germany

IGV, Germany

Algenteelt System, Netherlands

Vertigro, Texas

Algaetech, Indonesia

Huntley et al, Hawaii

Almeria, Spain

Sede-Boquer, Israel

Nannochlorops is sp

S. almeriensis

Cholrella vulgaris H. pluvialis

Unknown

C. sorokiniana

Chlorella vulgaris P. tricornutum

H. pluvialis

Chlorella sp

Chlorella vulgaris Subterraneus

Chlorella platensis Tricornutum sp

Chlorella sp

Spirulina

Chlorella sp

Chlorella vulgaris Chlorella sp

Algae Type

Rectangle Panel

Vertical Tube

Horizontal Tube

Vertical Tube

ETFE System

Vertical Tube

Vertical Tube

Helical Tube

High E Tube

Horizontal Tube

ETFE System

Helical Tube

Waterbed

Rectangle Panel

Vertical Tube

Triangle Panel

Triangle Panel

Triangle Panel

Rectangle Panel

Encapsulation

Unknown

Unknown

Unknown

Unknown

2.5 sqm

vary

Unknown

Unknown

10.4 sqm

Unknown

4.26 sqm

Unknown

5.72 sqm

1.24 sqm

9 sqm

5.64 sqm

10.15 sqm

9.05 sqm

1.89 sqm

Panel Area

Unknown

Unknown

Unknown

Unknown

All

North, South

All

All

All

All

All

All

All

South

South

All

All

All

South, West

Orientation

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

157 KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

49.92 KWh/m2/yr

35.54 KWh/m2/yr

- KWh/m2/yr

- KWh/m2/yr

67.4 KWh/m2/yr

19.3 KWh/m2/yr

54.78 KWh/m2/yr

50 KWh/m2/yr

Energy

2.2 kg/ m2/yr

9.57 kg/ m2/yr

5.49 kg/ m2/yr

-

-

-

-

-

29.2 kg/ m2/yr

3.46 kg/ m2/yr

26.6 kg/ m2/yr

41.5 kg/ m2/yr

83 kg/m2/yr

-

10.5 kg/ m2/yr

5.47 kg/ m2/yr

1.25 kg/ m2/yr

6.05 kg/ m2/yr

5.47 kg/ m2/yr

Biomass

290.3

248.5

231.5

204.2

186.3

ALGAEPARC

CELLANA

US MULTI FAMILY

US SINGLE FAMILY

ALGAE TURBO

ACCORDION

VERTIGRO

67 ALMERIA

66.2 URBAN ALGAE FOLLY

54.7 URBAN ALGAE CANOPY

50 BIQ HOUSE

24.2 LU ET AL

38.4

19.3 ALGAE FOLLY

HUNTLEY ET AL

15.4 SEDE-BOQUER

ALGONOMAD

9.3

157

581.5

The table above shows us various metrics and outcomes of any known algae bioreactor faรงade out there, both building related and non-building related. The Algaeparc in the Netherlands has the most productive rate of energy, nearly 600 kWh per square metre per year. It is twice the need of US multifamily housing electricity use intensity, which is around 250 kWh (CBECS, 2013). The chart below shows us the electricity generation of all the algae bioreactors compared to US averages.

Figure 40 Energy Production Comparison

Most of the building related case studies are generating less than a quarter of average US single family homes. However, the average US households are less keen on energy conservation so the number shown might represent normal homes without any interest towards renewable energy. Nevertheless, if algae bioreactor has to supply that much of an energy, a dedicated algae power plant in a waterbed system, similar to Algaeparc, must be built near the site.

Figure 41 Algaeparc Waterbed (www.kennislink.nl)

3. The Testbed: AlgaeShade 3.1 Objectives As a further measure of quantity and quality of Algae Bioreactor façade, a testbed of Algae Bioreactor shading device (AlgaeShade) will be installed in west façade of Intelligent Workplace, Margaret Morrison Carnegie Hall 4th Floor in Pittsburgh, United States. It takes the form of an algae bioreactor shading device, to test its integration with the existing façade. The reason behind choosing shading device over a façade panel is to increase the likeliness of installing algae bioreactor as an additional retrofit instead of replacing existing panels. Furthermore, the cost of constructing algae bioreactor shading is way less expensive compared to panels or ETFE. It is also easy to install so even those without engineering, design or construction background can do it by themselves. To acquire educated result from the testbed, the main objectives of building it as shading device are; 1. To assess the quality of algae bioreactor as shading device by measuring its temperature dynamics, light penetration and visual transmission 2. To quantify the biomass produced by an algae bioreactor shading 3. To calculate and predict energy outcomes, food production and carbon sequestration from biomass production in a certain period 4. To review the comparison between instalment cost and benefit for assessing any return of investments

3.2 Construction Detail The AlgaeShade device comprises of mainly the cultivation system; vertically stacked harvesting tubes with microalgae Chlorella Vulgaris circulated inside.

Table 12 Components List

Component Chlorella Vulgaris Culture Alga-Gro Medium Penn-Plax Airline Tubing Tetra 77847 CO2 Pump 1Hose 11110 Gal. Control Tank ½ HP Centrifugal Pump 2" Polycarbonate Tubing 16 Gauge Wire

Amount 12 10 1 1 30 3 8 8 6 6 1 1 50 25

Unit Litre Quart Roll Pcs Foot Foot Pcs Pcs Pcs Pcs Pcs Pcs Foot Foot

Basically, there are two types of equipment, the core cultivation equipment and supporting equipment. Core equipment are mandatory to have, it is hardly substitutional and it constitutes of microalgae seed, water medium, cultivation tubes and hoses, CO2 supply, pump and control tank. The detail specs of all core equipment can be seen on the following Table 13.

Table 13 Specification of core components

Component Type Microalgae seed

Name Chlorella Vulgaris Culture

Medium

Alga-Gro Freshwater

CO2 Supply

Tetra 77847 Whisper Pump

Cultivation Tube

Cultivation Hose

Sioux Chief 1-

Pump

Jecod 4000 Return Pump

Control Tank

1-

Specifications Green microalgae, bacteria free, packed with proteose agar medium, 220 C optimal temp, 200 to 400 foot-candles optimal light Sterile freshwater, bacteria free, pH 7.8, 0.7 vapour density, 17.5 mmHg at 20 0C vapour pressure weight, 0.5 L/min air flow, 115 V, 3W Thermoplastic polymer based, non UV protected, food grade, 220-230 0C melting point, 1.2 g/cm3 density, 8.1 lb per sqft, 78% light transmission, 0.56 UValue Plasticised polyvinyl chloride based, BPA free, non-toxic FDA listed, max temp 175 0 F, min temp -40 0F, weight 1.1 lb per ft 30 W power, 1056 GPH max flow rate, 9.8 ft max-head, 10 speed mode, IC electronic detection, super quiet, no copper, wear resistant ceramic shaft dimension

The rest of the components are categorised as supporting component, mainly to support the bioreactor so it stays still. Since there are existing structural pole to hang the AlgaeShade, the supporting components needed will be mostly tube clamps and connectors for the 1hose. The list of supporting components and its function can be seen below.

Table 14 Specification of core components

Component 11-

Bushing

116 Gauge Wire Penn-Plax Airline Tubing

Function Connect tubes with other tubes/hoses Connector between flex coupling and nylon barb Connector between PVC bushing and hose Support clamp for stacking the tubes vertically Soft padding for the clamp Additional stress wire to support the tubes Supply CO2 from pump to the control tank

Figure 42 Testbed Front Elevation

The construction method is a simple plug-and-place mechanism, with a little bit of cutting and joining but rather minimum. Figure 42 above shows the basic placement for the core port of existing 2righthand side of the span and two tubes stacked on the left-hand side. Such arrangements are due to lack of space. Ideally it will be 5 tubes in just one span. The algae flow will be from the topmost tube to the bottom most tube, therefore 1to the figure 42 above. Details on how to hang the tubes and plug the hoses is shown in figure 43 below.

Figure 43 Connection details

The main support item is the 1a buffer between the clamp and the structural pole to avoid any scratches while adding more friction so the clamp will not easily slide down. For the connection between the tube and the hose, 1will bridge the gap between both. The hose will be easily plugged into the barb since it has

almost the same diameter. The connections will also make the whole instalment leak proof without any sealant needed. Use of sealant is encouraged but not necessarily.

3.3

Measurement Methods

The testbed will run for approximately one month and various of measurement will be conducted weekly, daily or biweekly. The parameters which being reviewed are listed in the following Table 15.

Table 15 Measurement Parameters

Parameter Outside Temperature Tube Temperature

0

Unit C 0 C

Surface Temperature

0

Biomass Production

Gram

C

Time Daily Daily (10AM, 3PM, 6PM), minutely for three days Daily (10 AM, 3PM, 6 PM), minutely for three days Weekly

Note Acquired from IW weather station Tube 1, 2 and 3 (Using FLIR), using HOBO data logger Surface with AlgaeShade and surface without (Using FLIR). Using HOBO data logger as well Weighing the wet/dry mass

Outside air temperature is captured to benchmark any measured temperature on the bioreactor and window surfaces. The data will be acquired from IW weather station each time temperature measurement the bioreactor and window surface takes place. Since the algae bioreactor acts as a shading device placed on a second skin, the most sensible way to evaluate the shading quality of it will be by analysing its impact towards the window surface it protects.

Using a thermographic camera called FLIR One, the spot temperature of tubes, average surface temperature of window with bioreactor and average surface temperature of window with no bioreactor will be captured. The position of the FLIR camera can be seen on Figure 44 below.

Therefore, benchmarking the temperature difference between window with bioreactor and without will show how much of a shading the algae bioreactor is.

Figure 44 FLIR Usage Method

To further validate the thermal data, a follow up measurement will be taken for a duration of three days using HOBO data logger and thermocouples. One sensor will be placed on the surface with AlgaeShade, another one on the surface without AlgaeShade and the last will be placed on the AlgaeShade. Beside temperature measurement, biomass productivity will also be considered. Biomass production will be captured weekly, since doing daily scooping might interrupt the life of microalgae. It is said to best wait for 7 days (Qiu et al., 2013) to see optimum growth so biomass scooping will be done weekly. By capturing the thin layer of biomass on the bottom of control tank, the number of grams of biomass will be easily measured. The liquid mass then will be put inside a filter paper while exposing it to the sun so it will become dry. Boiling is an option as well, but must be done carefully since over-burning it might cause the nutrients to break. From biomass production, electricity generation, food production and carbon sequestration value can be calculated based on established formulas by various studies.

3.4 Results Built Algae Bioreactor Shading Device

Figure 45 From left to right: Newly hanged tubes and microalgae seed

The construction took place during July 12th until July 19th, 2017. A full week was taken due to several technicality problems such as inaccurate sizes of the component, support failures and others. Figure 45 shows the condition of the instalment during the 6th day. After the bioreactor tubes were successfully stacked, the microalgae seed and its medium poured down into the control tank where then the cultivation process started. Figure 46 below shows the second day of run (July 20th).

Figure 46 AlgaeShade second day

It was almost 90% translucent with slight green tint, showed minimum growth on biomass.

During this time, it is crucial to monitor the construction when there is high velocity wind or excess heat from sunlight. Although there was no leakage occurred, it is safer to observe the behaviour of AlgaeShade during rain or windy days or any extreme weather days to determine its sturdiness towards local disturbance. After almost one week, the microalgae grew substantially that it fills the AlgaeShade with shiny green liquid, as seen on Figure 47 below. It is visually pleasing, as the green shimmering light reflected from the tubes. The first and early second week was the best time for the AlgaeShade in terms of visual aesthetic, since the algae growth is on a medium speed.

Figure 47 AlgaeShade first week

The beautiful state of green translucent AlgaeShade lasted for a week and a half, where the microalgae boosted its growth exponentially afterwards. It renders the tubes dark green with relatively thick concentrate. Figure 48 below shows the look and feel of second week AlgaeShade.

Figure 48 AlgaeShade final look

If in the first week the visual transparency of AlgaeShade might have reached 60% to 70%, during the third week it went below 30%, without considering the gaps between the tubes.

Sunlight was not able to penetrate the thickness of the algae solution, making it look like a fully blocking shading device. Clear skies were one of the reason why the microalgae grew rapidly inside the bioreactor. Some of the biomass even got stuck on the tubes and cover it permanently. This was happening due to the inexistent of biomass filter. If there was a filter installed, whether on the pump or at the end of the tube set, the biomass generated from the tubes will easily captured without clogging anything.

Temperature Measurement Using FLIR One thermal camera adapter for iPhone, the temperature recorded for four days is shown in the following Table 16.

Table 16 FLIR Result

Date

Time

7/26 7/26 7/27 7/27 7/28 7/28 7/31 7/31

10 AM 6 PM 10 AM 6 PM 10 AM 6 PM 10 AM 6 PM

Weather Temp Sky 25.1 C Clear 26.8 C Clear 24.0 C Clear 28.9 C Clear 24.3 C Cloudy 25.6 C Cloudy 23.6 C Clear 29.3 C Clear

Tube 1 19.8 C 33.1 C 23.8 C 32.8 C 26.3 C 25.1 C 22.5 C 34.4 C

Average Temp Tube 2 Tube 3 20.0 C 19.2 C 33.1 C 33.3 C 23.6 C 23.6 C 32.9 C 32.8 C 26.2 C 26.1 C 25.1 C 24.8 C 22.1 C 21.9 C 34.7 C 32.8 C

Srf A 21.6 C 35.0 C 26.5 C 35.3 C 25.2 C 26.0 C 24.1 C 34.5 C

Srf B 24.7 C 37.0 C 27.9 C 35.8 C 27.1 C 27.6 C 26.4 C 37.7 C

Surface A is the surface with AlgaeShade and Surface B is the surface without. The outside air temperature data was acquired from IW weather station through the Open HAB app. By looking at Table 16, Surface A has mostly lower temperatures compared to Surface B. Although the AlgaeShade tubes have the coldest temperature, it seems that the shading effect acted on Surface A. It looks like there is almost an exact equation to calculate the delta T between both surfaces, which can be seen on the line chart below.

Figure 49 FLIR Result chart

One thing that definitely off is the outside temperature, where it seems to have no relation at all with the rest of the data, represented by green line on the chart above. Surface B, Surface A and average tube temp (red, blue and yellow line respectively), are close each other and maintained almost the same delta throughout the whole period. Unfortunately, thermographic images are not the best to measure fixed point temperature but it shows the dynamic range of temperature inside one frame. Therefore, the analysis of how the AlgaeShade is affecting its surrounding can be seen by comparing two thermographic images shown in Figure 50 below.

Figure 50 Left: Surface with AlgaeShade, Right: Surface Without

The left image shows the temperature range on the surface with AlgaeShade whereas the right image shows the surface without AlgaeShade. It is visible that the tubes of AlgaeShade are radiating cool ambient temperature to the surface. It managed to bring down the surface temperature to 26.5 C while the right image has an average temperature of 27.9 C. There is 1.4 delta T between them, which is quite significant. This happened possibly due to the AlgaeShade being a liquid substance that contains slightly cooler temperature. It might be a different case should the sun points directly to the AlgaeShade and heats the liquid inside. Therefore, to determine this finding more accurately, three thermocouples are placed on the installation as seen on Figure 51 below.

Figure 51 Placement of the thermocouples, left: surface with AlgaeShade, middle: surface without AlgaeShade, right: on the tube

The thermocouples are connected to HOBO data logger where it collects and plots the data into line charts and tables. The first thermocouple was placed on the surface without AlgaeShade, the second was placed on the surface with AlgaeShade and the last one was placed on the middle tube. The spots are similar to FLIR measurement as consistency throughout the whole experiment is crucial to be kept. The line chart on Figure 52 below shows the temperature fluctuations during a 4-day data acquisition.

Figure 52 HOBO data acquiring result

The chart shows three lines each represent temperature fluctuations on surface without AlgaeShade (red line), surface with AlgaeShade (blue line) and the AlgaeShade itself (yellow line). While in the previous FLIR-generated chart the order is always similar, the HOBOgenerated chart shows that even the AlgaeShade itself goes warmer than the surface it was covering. Especially during night time. The chart below shows more detail during daylight hours.

Figure 53 Temperature from sunrise to sunset

Surface without AlgaeShade rose its temperature to a high level of 35 C whereas surface with AlgaeShade still maintained its cool temperature due to AlgaeShade effect. Although around 2 PM when the sun angle is almost 900 up, the surface with AlgaeShade was slightly warmer than the surface without. This happened due to sunlight position that might hit the thermocouple directly during that time. The AlgaeShade managed to keep its temperature cooler than the surfaces until 7 PM where it rose to 25 C, the highest compared both surfaces. It maintained its high temperature during the rest of the night with reasons almost unknown. One of the possibility is that the microalgae was releasing oxygen to the tubes and caused an exothermic reaction. Something hardly noticeable during daytime due to hotter outside temperature.

However, further studies on microalgae photosynthesis chemical reaction must be done to exactly determine the cause of this effect.

Biomass Measurement

Figure 54 Biomass acquirement methods and result

Figure 54 above shows the steps of acquiring the biomass and the result of weekly monitoring.

By scooping as much as 1 to 9 litres of algae solution from the control tank, the ratio of biomass per litre can be calculated. After the scooping process, the algae solution is drained from the bottle and filtered through paper wraps so the biomass is captured. On this stage the biomass was still liquid so drying it under the sun will be the next step. After a long day under a summer sun, the biomass was forming something similar to powder that as dense as milk powder.

Simply shake the paper wrap and collect the biomass with any kind of container. Using a kitchen scale the dry biomass was weighed and the result for the second week was 89.73 grams from 9 litres. It means an average of 9.97 grams per litre. The third week was 29.89 grams from 3 litres, therefore the final biomass rate per litre is still roughly 9.97 grams per litre. Since the total volume of AlgaeShade is 56 litres and it has been running for 16 days, the daily production is estimated to be 34.9 grams per day. To compared it with a measurable dimension metric, the number divided by the total square metre of AlgaeShade which is 2.8 sqm. The productivity rate of AlgaeShade is 12.4 g/sqm/day.

Energy, Food, Carbon and Oxygen Predictive Calculation With 12.4 grams of biomass produced per square metre per day, the AlgaeShade is estimated to produce 31.6 kWh/sqm/year, 21 thousand kcal per year and sequester 3.13 kg of carbon daily, as equation 2 shows. The average lighting energy consumption for a single-family home in US is roughly 44.1 kWh/sqm/year (Perez-Lombard et al., 2007) so AlgaeShade can power almost 90% of it. For food benefit, 21 thousand kcal per year is as good as minimum annual calorie requirement for a 4-person family which is 22 thousand kcal (Leslie et al., 1984). The amount of carbon sequestered is also fascinating, with 3.13 kg of carbon per day, the performance equals to 100 trees of eucalyptus and pine in a hectare.

Equation 2 Benefits estimation

Figure 55 Visualisation of benefits

Cost-Benefit Calculation Another additional interesting fact of the AlgaeShade is how easy it is to build one. In terms of cost, the total instalment has $774.91 price tag on it. Somewhere between cheap and expensive, depends on the purpose of installing AlgaeShade. The price is equal to a triple glazing window in the same square area. However, windows are not able to produce electricity or food, which AlgaeShade trumps on both. The total breakdown of AlgaeShade cost can be seen on the Table 17 below.

Table 17 List of component price

Component Chlorella Vulgaris Culture Alga-Gro Medium Penn-Plax Airline Tubing Tetra 77847 CO2 Pump 111110 Gal. Control Tank ½ HP Centrifugal Pump 2" Polycarbonate Tubing 16 Gauge Wire

Amount 2 10 1 1 30 3 8 8 6 6 1 1 40 25

Unit Litre Quart Roll Pcs Foot Foot Pcs Pcs Pcs Pcs Pcs Pcs Foot Foot

Price/Unit $10.92 $28.15 $2.89 $8.12 $2.83 $1.42 $1.91 $3.90 $2.13 $4.11 $19.99 $64.95 $4.81 $0.41 Total Cost

Cost $21.84 $281.5 $2.89 $8.12 $84.83 $4.26 $15.26 $31.20 $12.75 $24.66 $19.99 $64.95 $192.45 $10.21 $774.91

Cost per sqm

= $774.91 / 3.6 sqm = $215.25 per sqm

Electricity generation

= 58 KWh annually

Electricity cost

= $0.12 / kWh (Average US electricity rate)

Electricity benefit

= 58 kWh x $0.12 = $6.96

Food benefit

= 6,329.5 grams per year

Algae powder price

= $16 per 226 grams (price on ebay.com)

Food benefit

= 6,329.5 / 226 x $16 = $448

With a total cost of $215.25 per sqm, the amount of money generated could reach up to $448 per year, which means 30-50% ROI rate. The price is considerably high due to the price of the Alga-Gro freshwater. There was time limit so dechlorinating tap water is not feasible, ergo buying an expensive medium. At the end, if the AlgaeShade were to installed in the whole faรงade, the price would possibly be much cheaper because buy-in-bulk deal and higher square metre coverage. One thing should be considered more is buying filter systems for the control tank and the pump. At some point, the biomass will accumulate on the bottom of the control tank and might probably clog the system. For AlgaeShade, the experiment will not last for more than one month, so filter system is not a necessity. Although there were a lot of liquid biomass sticking on the glass surface and rendering the control tank dirty, as seen on Figure 56 below.

Figure 56 Control tank needed to be filtered

4. Integrating Algae Bioreactor into Faรงade Design 4.1 Flowchart Design Decision

Figure 57 Design decision flowchart

Figure 57 above shows three major parameters for algae bioreactor design. While the three of them are independent of each other, some features in one parameter might have an impact on the other albeit minor. The three parameters are encapsulation type, algae type and production system. Orientation was a part of the parameters but it only mandates one design requirement, the algae bioreactor must be aligned with sun azimuth angle for maximum production. It is obvious and there is not much choice on that. Especially when it comes to climate, some area has constant sun radiation whereas others have not. It affects the design, through the microalgae type mostly, and of course orientation. Therefore, in deciding which encapsulation, algae and production, orientation to sun has to be pre-determined. For encapsulation type, the design decision is based on the type of surface which entails three categories; opaque, transparent and overhang. Opaque surface is a closed envelope such as walls and columns whereas transparent surface is open fenestration such as windows, storefronts and glazing.

Overhang is a shading platform which usually placed horizontally above an opening. In designing algae bioreactor for opaque surface, pursue of productivity is favourable since there is no need for light intakes. For transparent surfaces and overhangs, visual transmission has to be considered while productivity could not be compromised.

4.2 Type of Surface Based on these two types of surface, opaque and open (transparent), the encapsulation design can be classified further into two categories, panel frame system and dynamic system. Panel frame has more rigidness but universal, suitable for offices and residential whereas dynamic shape has more fluidity and expressiveness. It suits commercial and entertainment buildings.

4.3 Panel Frame System

4.4 Dynamic System

4.5 Pros and Cons

Figure 58 Pros and Cons of panel frame system

Figure 59 Pros and cons of dynamic system

4.6 Production Equipment

Figure 60 Production System

Production system acts as the main powerhouse for producing useful outcomes from biomass generated in the bioreactor. In selecting what kind of system is desirable, it is important to address the objectives of installing the algae bioreactor. Is it primarily for generating electricity, food, medicine, or any type of algae based products. For food, the most beneficial part of an algae is its protein therefore a simple drying process might do the trick. From the dried biomass, products such as algae drink, pills or algae tea can easily be made and sufficient for daily protein supplement. However, if there is specific outcome such as wheat or sweet grains, the biomass might have to go under a fermentation process. With glucose-rich nutrient inputs from beets, corn or sugar cane, the biomass will be fermented inside a chamber for a certain period of time until it comes as sweet powder. The fermentation chamber is categorized under heavy equipment therefore it might not be possible to put it on-site residential or commercial buildings. From sweet powder, possible food products generated are pastry, bread, wheat, pasta and any kind of yeast-based food.

Trickier than food production, energy production involves more sophisticated machineries. To complete the biofuel conversion process, the algae bioreactor needs to be connected to a flocculation machine, bead miller, enzymatic processor and combusti on chamber. Such equipment does not permissible for residential or commercial buildings. In case of industrial office or warehouse, the complete 5-step full system might potentially be the best solution.

However, in residential building, either simple drying process of filter system will do just perfectly. In BIQ House for example, the filter tank and flocculation system is located on the basement, directly connected to the algae bioreactor faรงade (Lakenbrink, 2013). The system automatically filters biomass and then flocculate them so then it is easy to ship to an off-site facility. There is also biofuel generator plugged into the main grid which converts biofuel into electricity. The solution is perfect for buildings with limited permit for heavy machinery as it

requires low voltage and risk. One additional feature which proves building integration and algae bioreactor is heat exchanger. In case the building has thermal storage such as geothermal boreholes, the heat collected by alga bioreactor can be transferred and stored to use during cold seasons. This solution had implemented by BIQ House and Supra-High, two precedents located in considerably cold climates. It was estimated that the algae bioreactor faรงade on BIQ House can collect and store heat as much as 6000 kWh per year (Lakenbrink, 2013).

Figure 61 Flocculation chamber on the basement of BIQ House

4.7 Algae Type

Figure 62 Algae Type

One of the important factors of designing high productivity bioreactors is determining the perfect microalgae type. Generally, every microalgae will grow optimum in a room temperature of 22 0C, but not all of them has the same optimum temperature range. Freshwater and marine coast algae for instance, they grow well between 15 0 C and 25 0C but more than 30 0C would be lethal for them. Some marine microalgae from the Pacific, such as Gleocapsa or Anabaena, prefer temperatures ranging from 5 0C and 15 0 C. Some of them even would not survive in a climate hotter than 30 0C. However, an increase in temperature might enhance biomass productivity until an equilibrium temperature is reached (Soeder et al, 1981). During that optimum temperature, microalgae can tolerate more high level of light before getting inhibited (Borowitzka and M. A., 1998). In warmer climates, most of algae bioreactors are using Spirulina maxima due to its monoculture conditions (Saeid and Chojnacka, 2015). For cold and mild, green microalgae such as Chlorella and Haematococcus would be much preferable because of their independency of constant sun light. Nevertheless, consulting an expert on biological science or zoology in determining the right microalgae type is much preferable.

5. Conclusion 5.1 Key Benefits Based on practical studies on algae bioreactors, four key benefits of algae bioreactor as a façade element are; Energy generation up to 31 kWh/sqm/year from a simple algae tubular bioreactor shading installation. It can power 90% of lighting consumption on an average US home.

Food production in a form of calorie, up to 21,000 kilo calories per year. Enough to feed a 4-person family with minimum protein requirement Carbon sequestration equals to 100 pine and eucalyptus or 3.13 kilograms of CO 2 each day Effective shading with performance of lowering surface temperature up to 2 0C cooler during hot season Combined with case study research and literature research, the potential of algae bioreactor is known to be limitless due to its technology age. It is fairly a new subject and there are lots to explore. Nevertheless, some of the research shown that the benefits of an algae bioreactor can be summed up into these; Energy generation up to 290 kWh/sqm/year using a helical tubes algae bioreactor.

Enough to fulfil an average electricity consumption (Perez-Lombardi et al., 2007) of office building in the US Food production of 227 grams per day using waterbed ETFE algae bioreactor On-site heat production using heat exchanger from algae flat panel bioreactor on BIQ House façade as big as 6000 kWh annually Carbon sequestration up to 12 kilograms per day by using flat triangle ETFE panels The benefits qualify algae bioreactor façade as a living façade and make it more approachable in designing the optimum system which will be elaborated in the next subchapter

5.2 Key Guideline Points Based on case study, literature study, and testbed experiment, key to designing algae bioreactor as a sustainable integrated building façade is down to three key factors, encapsulation design, production system integration and algae type. In encapsulati on design, some of the important factors are; Opaque surface versus open surface. In designing algae bioreactor for opaque parts of building façade, it is better to pursue for maximum productivity whereas in open surface such as fenestration and windows, the balance between light transmission or visual intake and productivity must be found

Deciding between panel frame encapsulation or dynamic encapsulation. Panel frame offers homogenous solution, it fits offices and residential. Dynamic encapsulation fits commercial and art buildings as it is more fluid and amorphous Always consider surface-to-volume ratio and sun light refraction for the encapsulation form In production system integration, key decision factors are; Fermentation chamber needed if there are specific outcomes of algae powder desired such as sweet or sour. Otherwise, simple drying process is already adequate to produce calorie in a form of supplement or drink Biofuel conversion takes 5 steps to accomplish and involves heavy machinery such as bead miller and combustion chamber. If no industrial permit given on the building, go for simple production equipment (filter system, auto flocculation and biofuel generator) to complement the algae bioreactor Connecting a heat exchanger to algae bioreactor is highly recommended if the building has heat storage facility such as geothermal boreholes In selecting the perfect microalgae species to fill the algae bioreactor, several key parameters to consider are; Most microalgae grow optimal in room temperature of 22 C and 200-500 footcandle light exposure, although some marine algae will not survive temperatures higher than 20 0C For cold and mild climate, green microalgae such as Chlorella sp and Haematococcus are suitable to grow due to its high survivability rate during low sunlight.

Spirulina maxima is one of the microalgae which highly suitable for warmer climate with temperature higher than 30 0C.

5.3 Limitations and Concerns Algae as renewable energy is relatively young technology albeit has been conceptualised years ago. This study tries to approach the idea and integrating it to infrastructure, especially buildings. Some of the limitations are Testbed experiment only ran for 3 to 4 weeks, hardly enough to conclude strong productivity growth and only represent hot season Testbed design did not perfectly resemble shading element. Temperature decrease on surface has to be investigated further Many of case studies do not measure energy production in a unit of energy but rather in biomass weight, so at the end the real electricity performance of algae bioreactor is still open to exploration

6. Bibliography Calthorpe, P. (2011). Urbanism and Climate Change. In Urbanism in the Age of Climate Change (pp. 724). Island Press/Center for Resource Economics Sardรก, R. C., & Vicente, C. A. (2016). Case Studies on the Architectural Integration of photobioreactors in Building Faรงades. In Nano and Biotech Based Materials for Energy Building Efficiency (pp. 457-484).

Springer International Publishing Palazzo, D., & Steiner, F. R. (2012). Urban ecological design: a process for regenerative places. Island Press Jiang, N., Yang, X. Y., Deng, Z., Wang, L., Hu, Z. Y., Tian, G., ... & Su, B. L. (2015). A Stable, Reusable, and Mesoporous Bilayer Nanoshell. small, 11(17), 2003-2010.

Karandikar, M., Kawadkar, N., & Wandre, S. (2016). Scientific Cultivation and Quality Control System for Futuristic Super Food-SPIRULINA. International Journal of Scientific Research, 5(1).

Shirokova, L. S., Kunhel, L., Rols, J. L., & Pokrovsky, O. S. (2015). Experimental modeling of cyanobacterial bloom in a thermokarst lake: Fate of organic carbon, trace metal, and carbon sequestration potential.

Aquatic geochemistry, 21(6), 487-511 Elsayed, S., Boukis, N., Sauer, J., & Patzelt, D. (2014). Algal Cultivation and Hydrothermal Gasification: Biomass and Energy Production.

Elzomor, M., & Youssef, O. (2015). Living and learning in practice: University of Arizona Engineering Innovation Building (EIB). In Research for a Better Built Environment: 49th International Conference of the Architectural Science Association (pp. 33-44).

Granata, T., Krehel, M., Wittkopf, S., & Egli, M. (2015). A hybrid facade that combines an algal bioreactor with photovoltaics. In Proceedings of International Conference CISBAT 2015 Future Buildings and Districts Sustainability from Nano to Urban Scale (No. EPFL-CONF-213381, pp. 567-572). LESO-PB, EPFL. Kim, K. H. (2014, June). Beyond green: growing algae facade. In ARCC Conference Repository.

closed solar photobioreactor for cultivation of microalgae under supra-high irradiance: basic design and performance. Journal of Applied Phycology, 15(2-3), 239-248.

Kim, K. H. (2013, July). A Feasibility Study of an Algae Faรงade System. In Presentation at the International Conference of Sustainable Building, Seoul, South Korea.

Dewidar, Y., Mohamed, N., & Ashour, Y. (2013). Living Skins: A New Concept of Self Active Building

Envelope Regulating Systems. In Advancing the Green Agenda; Technology, Practices and Policies Conference BUID (pp. 1-8).

Hunt, R. W., Zavalin, A., Bhatnagar, A., Chinnasamy, S., & Das, K. C. (2009). Electromagnetic biostimulation of living cultures for biotechnology, biofuel and bioenergy applications. International journal of molecular sciences, 10(10), 4515-4558.

Wilkinson, S., Stoller, P., Ralph, P., & Hamdorf, B. (2016). Feasibility of Algae Building Technology in Sydney. Feasibility of Algae Building Technology in Sydney.

Lakenbrink, H. (2013). Smart Material House BIQ. IBA Hamburg Building City Anew.

XTU Architects (2015). Symbio2. Dossier De Presse XTU. Colt, ARUP, SSC. (2013). Solarleaf Bioreactor Faรงade Product Overview.

Ducat, D. C., Way, J. C., & Silver, P. A. (2011). Engineering cyanobacteria to generate high-value products. Trends in biotechnology, 29(2), 95-103.

Hall, D. O., Markov, S. A., Watanabe, Y., & Krishna Rao, K. (1995). The potential applications of cyanobacterial photosynthesis for clean technologies. Photosynthesis research, 46(1), 159-167.

Pruvost, J., Le Gouic, B., Lepine, O., Legrand, J., & Le Borgne, F. (2016). Microalgae culture in buildingintegrated photobioreactors: Biomass production modelling and energetic analysis. Chemical Engineering Journal, 284, 850-861.

European Commission. (2006). Review of EU biofuels directive.

Lakenbrink, H. (2013). Smart Material House BIQ. IBA Hamburg Building City Anew.

Knothe G, Dunn RO, Bagby MO. (1997). Biodiesel: the use of vegetable oils and their derivatives as alternative diesel fuels. ACS Symp Ser;666:172 208 Calthorpe, P. (2011). Urbanism and Climate Change. In Urbanism in the Age of Climate Change (pp. 724). Island Press/Center for Resource Economics Sardรก, R. C., & Vicente, C. A. (2016). Case Studies on the Architectural Integration of photobioreactors in Building Faรงades. In Nano and Biotech Based Materials for Energy Building Efficiency (pp. 457-484).

Springer International Publishing Palazzo, D., & Steiner, F. R. (2012). Urban ecological design: a process for regenerative places. Island Press Jiang, N., Yang, X. Y., Deng, Z., Wang, L., Hu, Z. Y., Tian, G., ... & Su, B. L. (2015). A Stable, Reusable, and Highly Active Photosynthetic Bioreact Mesoporous Bilayer Nanoshell. small, 11(17), 2003-2010.

Karandikar, M., Kawadkar, N., & Wandre, S. (2016). Scientific Cultivation and Quality Control System for Futuristic Super Food-SPIRULINA. International Journal of Scientific Research, 5(1).

Shirokova, L. S., Kunhel, L., Rols, J. L., & Pokrovsky, O. S. (2015). Experimental modeling of cyanobacterial bloom in a thermokarst lake: Fate of organic carbon, trace metal, and carbon sequestration potential.

Aquatic geochemistry, 21(6), 487-511 Elsayed, S., Boukis, N., Sauer, J., & Patzelt, D. (2014). Algal Cultivation and Hydrothermal Gasification: Biomass and Energy Production.

Elzomor, M., & Youssef, O. (2015). Living and learning in practice: University of Arizona Engineering Innovation Building (EIB). In Research for a Better Built Environment: 49th International Conference of the Architectural Science Association (pp. 33-44).

Granata, T., Krehel, M., Wittkopf, S., & Egli, M. (2015). A hybrid facade that combines an algal bioreactor with photovoltaics. In Proceedings of International Conference CISBAT 2015 Future Buildings and Districts Sustainability from Nano to Urban Scale (No. EPFL-CONF-213381, pp. 567-572). LESO-PB, EPFL. Kim, K. H. (2014, June). Beyond green: growing algae facade. In ARCC Conference Repository.

closed solar photobioreactor for cultivation of microalgae under supra-high irradiance: basic design and performance. Journal of Applied Phycology, 15(2-3), 239-248.

Kim, K. H. (2013, July). A Feasibility Study of an Algae Faรงade System. In Presentation at the International Conference of Sustainable Building, Seoul, South Korea.

Dewidar, Y., Mohamed, N., & Ashour, Y. (2013). Living Skins: A New Concept of Self Active Building Envelope Regulating Systems. In Advancing the Green Agenda; Technology, Practices and Policies Conference BUID (pp. 1-8).

Hunt, R. W., Zavalin, A., Bhatnagar, A., Chinnasamy, S., & Das, K. C. (2009). Electromagnetic biostimulation of living cultures for biotechnology, biofuel and bioenergy applications. International journal of molecular sciences, 10(10), 4515-4558.

Wilkinson, S., Stoller, P., Ralph, P., & Hamdorf, B. (2016). Feasibility of Algae Building Technology in Sydney. Feasibility of Algae Building Technology in Sydney.

Lakenbrink, H. (2013). Smart Material House BIQ. IBA Hamburg Building City Anew.

XTU Architects (2015). Symbio2. Dossier De Presse XTU. Colt, ARUP, SSC. (2013). Solarleaf Bioreactor Faรงade Product Overview.

Ducat, D. C., Way, J. C., & Silver, P. A. (2011). Engineering cyanobacteria to generate high-value

products. Trends in biotechnology, 29(2), 95-103.

Hall, D. O., Markov, S. A., Watanabe, Y., & Krishna Rao, K. (1995). The potential applications of cyanobacterial photosynthesis for clean technologies. Photosynthesis research, 46(1), 159-167.

Pruvost, J., Le Gouic, B., Lepine, O., Legrand, J., & Le Borgne, F. (2016). Microalgae culture in buildingintegrated photobioreactors: Biomass production modelling and energetic analysis. Chemical Engineering Journal, 284, 850-861.

European Commission. (2006). Review of EU biofuels directive.

Lakenbrink, H. (2013). Smart Material House BIQ. IBA Hamburg Building City Anew.

Knothe G, Dunn RO, Bagby MO. (1997). Biodiesel: the use of vegetable oils and their derivatives as alternative diesel fuels. ACS Symp Ser;666:172 208 Calthorpe, P. (2011). Urbanism and Climate Change. In Urbanism in the Age of Climate Change (pp. 724). Island Press/Center for Resource Economics Sardรก, R. C., & Vicente, C. A. (2016). Case Studies on the Architectural Integration of photobioreactors in Building Faรงades. In Nano and Biotech Based Materials for Energy Building Efficiency (pp. 457-484).

Springer International Publishing Palazzo, D., & Steiner, F. R. (2012). Urban ecological design: a process for regenerative places. Island Press Jiang, N., Yang, X. Y., Deng, Z., Wang, L., Hu, Z. Y., Tian, G., ... & Su, B. L. (2015). A Stable, Reusable, and Mesoporous Bilayer Nanoshell. small, 11(17), 2003-2010.

Karandikar, M., Kawadkar, N., & Wandre, S. (2016). Scientific Cultivation and Quality Control System for Futuristic Super Food-SPIRULINA. International Journal of Scientific Research, 5(1).

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