Energy Exchange_Barcelona case study by Alvaro Cerezo

Energy Exchange Barcelona

This booklet illustrates research on understanding how existing energy consumption and potential solar energy production time patterns could help us to redefine the way we see our buildings from static, emitting, and consuming infrastructure to performative, self-sufficient, and interconnected nodes in a new distributed network of communication for the exchange of data, energy, and resources in general, tackling pressing urban issues, such as energy prices and environmental emergencies. The final outcome of the research includes urban analytics, the design of a strategic plan, and the creation of an interactive urban simulator. in the case study of the Poblenou district in Barcelona city. However, the analysis and methodology applied could be implemented in new locations around the world as well.

Energy Exchange

Project developed at IAAC, Institute for Advanced Architecture of Catalonia, by Marta Galdys, Nadh Ha Nasser, Alvaro Cerezo Carrizo, Riccardo Palazzolo Henkes & Juan Pablo Pintado Miranda 3

Content 1.0 Abstract 2.0 Towards Energy Exchange

2.1 A global context

2.2 Energy and time patterns

2.3 Policies - New energy model

3.0 A new approach - Flatten the curve

3.1 Methodology 3.2 Data, tools and sources

4.0 Analysis

4.1 Energy patterns

4.2 Energy interactive tool

5.0 Strategies

5.1 Mitigation

5.3 Energy exchange

5.2 Production

6.0 Conclusion 7.0 Bibliography

Abstract The energy supply sector is the largest contributor to global greenhouse gas emissions and is responsible for approximately 35% of total emissions, of which households account for 29%. The importance of making the energy supply sector more efficient has given way to a new paradigm, moving from centralized to decentralized energy systems. Traditionally, energy production consists of a power plant that serves a specific city or region, generating energy through nuclear power plants, hydroelectric power plants, or oil. New decentralized systems based on renewable energy offer new opportunities for the creation of more self-sufficient and more sustainable cities, where citizens are more responsible for both the energy they can produce and their consumption. The democratization of technology and its lower costs offer new opportunities to renewable energy production methods such as solar, wind, or biomass and also to self-consumption, turning consumers into small producers. This situation allows the closure of the existing space gap between production and consumption, as energy is produced closer to where it is consumed, reducing not only the costs of

energy transportation but also the loss of this while is transported. It is about using renewable and clean energy sources, such as the sun and wind, where the necessary technologies increasingly require lower and affordable initial investments. This new scenario should be encouraged by public administrations with the cooperation of other public and private entities and involving citizens and neighborhood communities. In the field of regulation, implementation, and governance, the creation of scenarios that favor private investment and governance systems are required, where the owners also have an active role, especially to adapt their buildings. It is also necessary to consider the technological opportunities that are being implemented in urban areas concerning the electrification of cities. Electric vehicles have great potential in encouraging the electrification of the city and its decarbonization, as they will not only revolutionize urban mobility but can play a relevant role in the energy field with their batteries and the need to increase the number of charging points. The study area is the 22@ inno-

vation district of the city of Barcelona. This area has witnessed great changes in the last 20 years, playing an important role in the implementation of innovations in the city such as the centralized heat and cold network of Districlima or the Superilla. The variety of uses and its construction potential represent two relevant factors when it comes to understanding how energy consumption can be influenced by the uses of buildings. The aim of this project is to add an energy perspective to the area, using the technological possibilities to create a more ecological and efficient system. This project is in line with the principles and framework established by the MES Barcelona municipal mechanism, promoting a new energy model for Barcelona, with public and private interest groups, and a series of projects focused on reducing consumption or promoting production capacity. This project can facilitate the understanding of a mixed policy of building renovation, photovoltaic energy production, and an energy exchange system to slowly implement a more sustainable, decentralized, and self-sufficient energy system.

Bettmann. (2020, May 18). Smokestacks from factory in Pittsburgh, Pennsylvania, belch black smoke into the atmosphere, 1890s. [Photograph]. https://photos.com/featured/ smokestacks-polluting-pittsburgh-bettmann.html

Towards

Energy Exchange

The energy supply sector remains highly dependent on non-renewable carbon-intensive production methods. In order to address the climate emergency, it is necessary to move from a system based on a polluting source of energy to another based on cleaner sources complemented a change in lifestyles and consumption. It is about rethinking how energy is produced and how it is consumed. In relation to production, new technologies make it possible to obtain energy in a cleaner, more efficient, and decentralized way, such as the installation of photovoltaic panels on the roofs of

private buildings; in terms of consumption, the system of tariffs for time slots has undoubtedly changed consumption habits, but it is necessary to have a new mindset based on values such as sustainability and efficiency. New sources of energy production and new consumption habits imply a great benefit not only environmentally but also economically, as the costs necessary for the implementation of more efficient strategies are often being financed by public administrations and private energy suppliers. Individuals or entire communities require very low or

fully funded initial investments and in the long term can generate income from the sale of the excess energy generated. Finally, another factor to consider is the uncertainty of energy prices, which is subject to variations in gas prices and carbon market legislation and is recently reaching historic prices. In this context, the promotion of more sustainable and decentralized energy sources represents an opportunity and a need to achieve greater energy self-sufficiency that respects the environment.

Energy & Time Patterns

Energy and climate emergency

A new energy paradigm cannot come without its own challenges. One of the most important is the productive capacity of photovoltaic systems. According to the methods used, in the case of solar energy, energy can only be collected during the day when consumption is relatively low, implying the need to have a storage infrastructure. One possible solution is storage batteries, but price and capacity remain the main impediments to making them a viable option. Thus, this time imbalance between when energy is produced and when it is consumed requires other solutions.

This project proposes a complementary solution to batteries, as it is based on the concept of establishing energy communities where energy is transferred between buildings that have excess energy to others that need it. Energy exchange can be promoted within a single block or on a scale large enough to reach a certain balance between buildings that usually generate excess energy and those that demand it. The collection of data, the preparation of simulations, and the analysis of the scenarios generated offer the possibility of understanding how Barcelona in general and Poblenou, in particular, can implement a new reference urban energy model.

New Energy Model Policies Aligned with the global need of reducing the impact of Climate change, the City Council of Barcelona has been working on making its part, being one of the cities leading the transition towards a more sustainable model. The Climate Emergency Declaration, which aims to make Barcelona a carbon-neutral city by 2050, or Barcelona’s 2030 Agenda, aligned with the SDG, are the main examples of the Barcelona City Council’s commitment towards new energy models. Particularly relevant for this project is the MES Barcelona, recognized by the UN as the most sustainable public-private collaboration out of 70 models. This framework offers the proper tool to promote a new energy model, considering both public and private sectors. It distinguishes two types of projects: the active measures are focusing on facilitating the installation of photovoltaic solar panels and other renewable energy sources; the passive ones are aimed at improving insulation, replacing windows and building envelopes, improving façades, etc. The novelty of this tool is that it does not require investment from building owners, since the energy savings and energy generated are the payback of the investment, moreover, they can propose their building and this will be evaluated by the investors, considering its viability and defining the conditions. The project prroposed in this document fits perfectly the MES Barcelona mechanism, providing approximative and reliable information about the potential energy savings and energy that can be produced.

Image Source: Ajuntament Barcelona (n.d.). MES Barcelona [Illustration]. MES Barcelona. https://ajuntament.barcelona.cat/agenda2030/en/mesbarcelona

A New Approach

Flattening The Curve What does “flattening the curve” mean? One of the challenges of the rise of photovoltaics is the duck curve problem. This is characterized by an imbalance between when the energy is consumed and when the energy can be produced. As it can be seen in the below graphs, there is a higher demand of energy in the morning and at night, while the production capacity is concentrated in the hours of sun. These variances of energy create a “bottleneck” that requires technology and systems that might provide storage capac-

ity or can promote energy exchange between buildings that are generating energy and the ones that are needing it. Microgrid technology is part of the solution to make the system more adaptable and resilient, but it’s not enough. Experts believe that in order to get to at least 80% renewable energy, it would be needed spatial diversity, and short duration storage; this is only possible with a mix of strategies that go from building scale to district scale. The approach of this project rotates around the concept of

flattening the curve by promoting a balance between energy consumption and energy production. The first one can be better reduced or managed by promoting energy efficiency at the building scale. A larger impact could be reached by also applying measures targeting consumption behavior. The implementation of photovoltaic panels can boost the local production capacity, increasing the use of renewable energy and building a more decentralized energy system.

Methodology The methodology of the project is based on 4 main parts: Analysis

Consumption data and production data have been collected and analyzed to understand how much energy is consumed and how much energy could be produced per building. The data have been collected both for winter and summer, considering the different consumption and production patterns: land uses, total surfaces, energy certificates, consumption patterns, and solar radiation. Evaluating

The data gathered has been used to develop the specific consumption and production patterns per building. This information allows identifying the consumption of energy at different scales, from the district one of a large part of Sant Martí to the building one according to the uses of each of its buildings. Catalogue

Considering the consumption and production characteristics of each building, different categories have been created to bring together buildings with similar characteristics and thus facilitate the implementation of one measure or another according to specific needs. The main categorization criteria were the energy balance of each building and the estimated energy certificate. Strategy

The strategies are partially aligned with the MES Barcelona tool since they are focused on the promotion of photovoltaic energy and building renovation but they also consider the potential of establishing energy communities that can finally promote the flattening of the curves.

Data, Tools and Sources wo solid datasets have been generated to support all the calculations of the project. The reason of it is the variation of energy consumption pattern and the different daylight hours between the winter and the summer season. Both datasets contain the following data: Real uses per floor and per building

It gives a real perspective on the uses per building, considering the different uses with specific consumption patterns. The specific uses being considered are a restaurant, church, small office, large office, secondary school, outpatient, standalone retail, large hotel, supermarket, and strip mall. Total average per building of the energy certificates per floor

Each floor might have different energy certificates, therefore this average data facilitates the calculation considering all the uses within a building. It allows assigning an energy certificate to each building. Hourly energy consumption pattern

It is base on the consumption pattern defined per different uses. Specifically considers how much energy is being consumed in specific hours of the day/night. Potential production capacity

It has been simulated considering the rooftop area and the height of each building. Based on this information, the solar exposure has been simulated and the energy capacity estimated.

The main sources used have been: - The Spanish Cadastre - Catalan Energy Institute - Goolzoom - Nationwide Analysis of U.S. Commercial Building Solar Photovoltaic (PV) - PyME energy Check Up - Enectiva - Omni Analytics - Smarkia

Analysis

Energy patterns

The data gathered has been structured to simulate how the study area would perform in terms of energy production and energy consumption patterns. The time variation, both in terms of seasons but also in terms of hours, has been taken into account for the preparation of the data. All the data that has been gathered allows defining per each building specific characteristics considering the data structure previously presented. Understanding how the site works in terms of energy consumption and production is necessary to understand what are the more suitable strategies. The temporal layer has been considered due to the variance of energy consumption and production between summer and winter and between day and night.

Winter-Summer

Day-Night

Being aware of the different day-light hours and energy consumption between winter and summer, the analysis is based on two different datasets. In the simulation, the production capacity is larger in summer than in winter due to the more day-light hours available, in contrast, the consumption is higher in winter, both for heating purposes but also due to the higher amount of nighttime. In the project, both seasons have been considered, although in the strategy section it is shown only the summer data to facilitate the understanding and focus more on the capacity of each strategy in improve the performance and efficiency of energy communities and achieve the goal of flattening the curve.

The time variation within a day has been used to define both the energy consumption and the energy production curve. While the consumption varies per land use and it manages to be a constant just with different peaks and valleys values, production is concentrated in the hours of the day where photovoltaic panels can generate energy. It is possible to obtain 24 scenarios per season, 48 in total. As previously explained, there is an imbalance between the hours of energy production and the ones of energy consumption. In the following pages are presented 12 scenarios covering the entire day, showing the variance of capacity in terms of energy consumption and production.

Energy Consumption Patterns

Energy Production Patterns

Energy Balance

The consolidation of production and consumption data allows the categorization of each building based on its specific energy balance. Four different categories have been defined: great producers, which generate a large amount of energy in comparison of their consumption; producers that have a positive balance to be self-sufficient; consumers, with a negative balance but close to be self-sufficient; large consumers that are consuming a large amount of energy, far beyond their production capacity. As it can be seen in the maps and the graphs, the number of consumers and large consumers is more common than producers and great producers.

Energy Exchange Interactive Tool

Strategies

Mitigation, Production & Exchange Once all the data within the tool has been organized and the main views on the urban fabric of the model have been extracted, an action plan has been developed to promote a new energy model in the area. of study. The project includes 3 different strategies that will be implemented in consecutive phases: mitigation of energy consumption, an increase of local energy production through photovoltaic panels, and optimization of the current electricity grid through a new energy exchange system. The first two are developed on a building scale, while the last is applied to the entire district.

Strategies Baseline The proposed action plan builds on the conclusions drawn from the data analysis for each building in terms of its energy consumption pattern and energy production potential. The comparison of both variables makes it possible to define a potential self-sufficiency index for each element of the entire urban fabric of the district, in the event that solar photovoltaic panels are installed on the roofs. The dispersion diagram, previously integrated into our categorization tool, is the main tool used to track all the buildings in the Poblenou district and study the evolution of their energy balance during the implementation of the different strategies. As previously explained, the position and distance of each building on the diagonal intermediate line, which represents a neutral energy balance or self-sufficiency capacity, will determine the strategies to be applied to each building and at what stage of the transition model should they be carried out. Those with a positive energy balance, once the photovoltaic panels have been installed, are shown in blue at the top of the diagonal midline, while buildings that, despite this, still have a negative energy balance, appear in the lower half in red.

1345

1753

buildings

Energy balance

Strategies Buildings renovation The first strategy focuses on buildings that have been shown in red in the scatter plot previously described. All of them, most of the district’s real estate stock, would have a negative energy balance, even if some photovoltaic panels were installed. The first step is to reduce current energy consumption through a renovation plan, in which the criteria for selecting the buildings to intervene first will be based on their energy certification, as a way to classify their potential for improvement to be self-sufficient. In an energy certification system where the letter G represents the least efficient buildings and the letter A the most efficient, the proposed intervention focuses on the buildings assigned with letters from G to D. The potential for reducing current consumption fluctuates. between 80% in the case of the letter G and 22% in the case of the letter D. There are several actions that can be carried out in each building depending on its energy certification, from windows and insulation from facades to appliances or heating system renovations, each with different involvement in the final overall percentage of energy consumption reduction. 3 phases of intervention are proposed, starting with the buildings furthest from the desired self-sufficiency and ending with the nearest ones. Once all the phases have been completed and the renovation measures have been applied, more than 1500 new buildings with a positive energy balance appear in the district, represented in blue in the dispersion diagram. In conclusion, total energy consumption in the 22@ district could be reduced by almost 45%.

1729 buildings to renovate 1516 new positive balance buildings Heating & cooling system upgrade Facade & windows insulation

Strategies

Strategies Solar PV production As mentioned above, the renovation process of each building must be combined with the production of solar energy on the roofs to achieve real self-sufficiency. The installation of photovoltaic panels is the second strategy integrated into the action plan for the district. These panels will help to further reduce the energy consumed during the hours of sunshine and, together with a system of batteries, placed in the common areas of our buildings, can generate an excess of energy that could be stored and then exchanged inside or outside the building. The proposed strategy now focuses on buildings with a positive energy balance, represented in blue at the top of the scatter plot. For each of the 3 phases proposed in the renovation process, the new buildings appear as potential energy producers. Those have been chosen that the installation of photovoltaic panels should be financed with the Barcelona MES program, starting by classifying them into three different groups according to the maximum amount of energy they could collect to share later, from high producers in a darker blue to low producers in light blue. Its ability to generate this excess energy is directly related to its distance perpendicular to the diagonal midline of the scatter plot, the greater the distance to it, the greater the excess energy that can be shared. After the clustering process, it is proposed to include more than 400 buildings, considered as superior producers to the structure of the Barcelona MES, while the rest can be part of alternative public or private initiatives.

2861 potential solar PV producers 544 potential high production buildings

Solar PV panels installation 80 kW/day

Domotics

Solar battery banks 50 KWh

Strategies Energy exchange After applying the second strategy with the installation of photovoltaic panels in buildings selected for both public and private initiatives, the total energy consumption at 22 @ could be reduced by an additional 45% during the summer months and 20% during the winter. However, the remaining problem is that there would still be a big difference between peak and low hours in the district. Therefore, the third and final strategy is directly related to the flattening of the consumption curve. A new decentralized energy system is proposed around 22 @, through the transformation of the existing electricity infrastructure into a new smart micro-grid and the development of a larger energy storage system at the district level. This new energy system would send the excess energy generated in some buildings to those who, despite the two previous strategies, would still need external energy to meet their demand. First, we would identify each of the buildings that still have an energy deficit, which appears in red on the negative side of the balance of the last scattered plot, and we look for the ten closest neighbors who might be interested in sharing energy. Second, it compares the energy balance of producers with the energy needs of the receiver to find the perfect combination for each time period and allow for exchange.

237 remain negative balance buildings

Smart Microgrids 16-93% ROI Distributed Energy Storage 3 MWh

Real-time demand response

Conclusions Exchange The application of all the strategies generates a new scenario, with higher energy efficiency, a large number of local energy production, the generation of energy communities, and overall a new decentralized energy production system. This scenario represents the final result of a transition process where each of the introduced strategies can be implemented gradually and partially independently since energy efficiency and energy production are independent of each other, while the energy exchange requires at least a certain amount of producers. Compared to the baseline, the number of buildings with lower energy certificates sink and the number of buildings with better energy certificates depends on the number of buildings that improve their efficiency and how much they manage to improve. Beyond considering the new scenario in terms of buildings, energy-wise, the total energy consumption is not only less (due to new efficiencies) but also greener, due to the installation of photovoltaic panels. To conclude, the energy consumption curve has been flattened by all the strategies presented, which implies a reduction of variance between peak hours and valley hours. This less variation also represents an opportunity to reduce the stress that grids are experimenting with and can promote new ways of design and implement energy infrastructures, which could have a smaller scale and be more decentralized.

10.878 GWh energy consumed Before

Current Building’s consumption

Mitigation strategy -42% energy consumption

Production strategy -46% energy consumption (PV)

After

Current Building’s consumption Energy Efficivient building’s consumption Energy efficient building’s consumptions with PV solar Grid integrated building with energy eficiency solar PV and load flexibility

Bibliography & data sources Barcelona City Council. “MES Barcelona” 2020 https://ajuntament.barcelona.cat/agenda2030/en/mesbarcelona Davidson, Carolyn; Gagnon, Pieter; Denholm, Paul; Margolis, Robert. “Nationwide Analysis of U.S. Commercial Building Solar Photovoltaic (PV) Breakeven Conditions”. 2015 https://www.nrel.gov/docs/fy16osti/64793.pdf Enectiva. “Energía en edificios de Oficinas”. 2015 https://www.enectiva.cz/es/blog/2015/06/ideas-energia-edificio-de-oficinas/ Lacomba Albert, Celia; “Auditoría y certificación energética del colegio público Vicente Artero en Castellón” 2018 https://fdocuments.ec/document/auditoria-y-certificacion-energetica-del-colegio-publico-se-define-entonces.html Mendoza, Elva. “MALLS 4.0. El siguiente nivel energético”. 2019 https://retailers.mx/malls-4-0-el-siguiente-nivel-energetico-2/ PMI Energy CheckUP. “Bares y restaurantes: promedio del consumo energético en el sector. Principales medidas de ahorro”. 2014 https://energycheckup.eu/uploads/media/Bar_Restaurants_Brochure_SPAIN.pdf Quesada Vázquez, Alejandro. “Auditoría energética de una superficie comercial de 1.610 m2”. 2017 https://core.ac.uk/download/pdf/78634621.pdf Saavedra, Néstor; Masís, Guillermo; Ardila, Germán. “Diagnóstico energético en el centro de salud Leonel Rugama, Estelí, Nicaragua” 2010 https://upcommons.upc.edu/bitstream/handle/2099.1/9290/G10-2009-EST_MEMORIA.pdf Selectra. “How Much Energy Does The Average Church Use?” 2021 https://selectra.co.uk/energy/guides/consumption/church-energy-usage Smarkia. “La importancia de la monitorización energética en los centros comerciales”. 2015 https://www.smarkia.com/es/blog/la-importancia-de-la-monitorizacion-energetica-en-los-centros-comerciales Wright, Nicole. “Beginner’s Data Analysis: Examining Energy Data”. 2017 https://oaiti.org/case-studies/energy-usage/#42 Datos Mundial. “Hora de Amanecer y atardecer España” https://www.datosmundial.com/europa/espana/puesta-del-sol.php Energy transition. The United Nations. 2021 https://www.un.org/sites/un2.un.org/files/2021-twg_2-062321.pdf Energy.gov. “Confronting the dck curve”. 2017 https://www.energy.gov/eere/articles/confronting-duck-curve-how-address-over-generation-solar-energy#:~:text=The%20 duck%20curve%E2%80%94named%20after,demand%20peaks%20in%20the%20evening. Pv Europe. “Solar irradiation data for all European regions” 2015 https://www.pveurope.eu/solar-generator/solar-irradiation-data-all-european-regions

Project developed for : https://iob.iaac.net/

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Project developed at IAAC, Institute for Advanced Architecture of Catalunya, by Marta Galdys, Nadh Ha Nasser, Alvaro Cerezo Carrizo, Riccardo Palazzolo Henkes & Juan Pablo Pintado Miranda 21st June 2021 45