Every light has its shadows: photovoltaic power by Elia

EVERY LIGHT HAS ITS SHADOW:

PHOTOVOLTAIC POWER Laboratorio di Sintesi Finale A.Y. 2012/2013 M. Sc. Communication Design Section C3

A Project by Giulio Bertolotti Elia Bozzato Gabriele Calvi Stefano Lari Gianluca Rossi

INDEX 0. INTRODUCTION 0.1 Adaptation to the climate change: energy 0.2 Field of interests: renewable energy source

1. CONTROVERSY 1.1 The choice of the issue: solar photovoltaic 1.2 The controversy of the convenience 1.3 The definitive question 1.4 The goal

2. RESEARCH PROTOCOL

5 6 6

9 10 12 14 15

3. ANALYSIS 3.1 First move: Harvester and Alchemy API 3.2 Problems with the results by Harvester 3.3 Manual selection of the definitive keywords 3.4 Most recurring keyword among categories 3.5 Eighty URLs: the definitive corpus 3.6 Manual evaluation of the tags positioning 3.7 The actors and their relationships

4. CONCLUSIONS 4.1 General overview on main focal points 4.2 Focal points along the life cycle of panels

21 22 23 26 32 38 47 56

59 61 64

INTRODUCTION

0. INTRODUCTION

0.1

0.2

ADAPTATION TO THE CLIMATE CHANGE: ENERGY

FIELD OF INTEREST: RENEWABLE ENERGY SOURCES

Climate change has proved to be a hard fact during last decades, whether or not caused by human activities. Apart from the debate over the responsibility it is then crucial and mandatory to todayâ&#x20AC;&#x2122;s society taking measures in order to mitigate its impacts on human life itself and on the environment. None of the aspects of human activities is excluded from those necessary policies, all the more vital issues strongly connected with the debate such as the ones related to energy supply and production. The choice among primary energy sources is in fact considered fundamental turning point towards the mitigation.

Our first step of analysis, which took the shape of a poster, tried to summarize and map the entire structure of actors, relationships and fluxes that have a significant role within the choice of energy sources. First of all we detected the environmental factors that raise the question of new energy policies, afterwards we defined social and economical entities who take part in the process of choice with their interests and then we investigated the main features of energy sources that can lead to a particular preference. What clearly emerged at first sight from this all is the total opposition between renewable and fossil energy sources, since the former are being increasingly preferred for their wide availability and their weak environmental impact while the latter have historically been preferred for their convenient costs and efficiency. According to our first results thus, we decided to delve deeper into the matter of renew-

THE ENERGY DECISION CHAIN

that traditional energy production involves collateral waste products both contributing to the greenhouse effect responsible of climate change and presenting difficulties in dumping, considered the continuous growth of population, standard of living and energy demand and established that fossil energy sources are likely not to be able to provide enough energy for long, it is nowadays a compulsory order of the day reviewing of our energy supply in order to adapt to these forcing environmental features. Renewable

During last decades, the discovery of significant impacts of human activity on the environment has risen serious questions about the sustainability of our current society, in particular in the field of global energy supply. Proved

and the flexibility of production according to the demand through the time.

energy sources are therefore gaining a more and more central role, even if in this scenario the choice among different energy sources is determined by a complex system of relationships among several actors led by various interests, mainly based on technologic and economic factors. In particular, the factors identified as discriminating within the choice are represented first of all by the costs of the energy sources, then by their emissions in terms of greenhouse gases, the physical efficiency of the related technologies

project by

0. INTRODUCTION

Giulio Bertolotti Elia Bozzato Gabriele Calvi Stefano Lari Gianluca Rossi

IEA REFERENCE SCENARIO EREC E(R)EVOLUTION SCENARIO

TEMPERATURE & Co2 CONCENTRATION 280 ppm 13,5°C

455 ppm 440 ppm 15°C 14,5°C

387 ppm 14,5°C

550 ppm

15°C 14,8°C

500 ppm

14,6°C 450 ppm

14,4°C

400 ppm

14,2°C 14°C

350 ppm

13,8°C 300 ppm

13,6°C 13,4°C

1850

1860

1870

1880

1890

1900

1910

1920

1930

1940

WORLD POPULATION & ENERGY DEMAND POPULATION GROWTH ENERGY DEMAND

4,706 mld 277 EJ

10 mld

1950

1960

1970

1980

1990

2000

2009

492 EJ

1 GT = 1.000.000.000 Tons 800 EJ

19 GT Co2

40 GT Co2

41 GT Co2 23 GT Co2

30,5 GT Co2

80000

700 EJ 8 mld

61718 EJ

36136 EJ 38025 EJ

48948 EJ

60000

30 GT Co2

500 EJ 20 GT Co2

project by

Giulio Bertolotti Elia Bozzato Gabriele Calvi Stefano Lari Gianluca Rossi

IEA REFERENCE SCENARIO EREC E(R)EVOLUTION SCENARIO

TEMPERATURE & Co2 CONCENTRATION

50000

400 EJ

and the flexibility of production according to the demand through the time.

70000

600 EJ

6 mld

THE ENERGY DECISION CHAIN

AVAILABILITY DECREASE

WORLD NON RENEWABLE ENERGIES EMISSIONS 8,31 mld 8,31 mld 674 EJ 501 EJ

7,143 mld

250 ppm

2030

280 ppm 13,5°C

40000

455 ppm 440 ppm 15°C 14,5°C

387 ppm 14,5°C

550 ppm

15°C 14,8°C

300 EJ

30000 10 GT Co2

20000

2005

2009

2030

1980

2009

OIC

OIL OWNERS GOVERNMENTS

RESEARCH

ONG

N.R.E. PRODUCTION COMPANIES

PUBLIC OPINION INGS

NUCLEAR 2 %

STRY

INDU

SEASON

45 %

SEASON

45 %

HOURS

75 %

YEARS

45 %

MINUT

45 %

MINUT

35 %

MINUT

35 %

MINUT

35 %

gCo wh 2/K

COS €c/ TS Kwh

90 %

N LE

400

wh 2/K

GEOTHERMAL

OCEAN

BIOMASS

HYDROPOWER

WIND

COAL

OIL

NUCLEAR

GAS

GAS 22 % COAL 28,4 % wh c/K

c/K

35 %

o2/K

0 gC

8€

MINUTE

5€

wh c/K

c/K wh

15566 EJ

2250 EJ

35 %

6€

wh c/K

MINUTE

/Kw

6€

15556 EJ

15566 EJ

6000 EJ

147 EJ c/K wh

,4%

ILD

YEARS

42 ,8%

gCo

35 %

/Kw

6€

8,8

,4%

LTUR

RICU

FIN CY

,3%

14 3,3%

7400 EJ

0,7%

wh 2/K

13 % ,6

,5%

EFFICIEN 37%

gCo2

c/K

R ON

gCo

MINUTE

/K gCo2

100

8€

870

7400 EJ

NG ISI VERTOICE CH

400

wh 2/K

45 %

gCo2

OICE

RENEWABLE

870

€c/

0 gCo 100

MINUTE

/Kw

1400 EJ

SOLAR

OICE

2/K

45 %

gCo2

gCo

YEARS

gCo2

€c/

OICE

N CO

/Kw

gCo2

wh 2/K

AVAILABILITY 3.900.000 EJ

gCo

75 %

S ION wh ISS /K EM gCo2 50

15 COST €c/ S Kw h

L RE

ATIO

HOURS

INFO

ATIO

OICE

FLEXIB ILITY SEASON S

INGS

LOGI

OICE

wh 2/K

45 %

ATIO

INFO

INGS

BLE

IVE

INCE

gCo

SEASON

45 %

wh 2/K

FIN SEASON

E AL

90 %

RENEWABLE

YEARS

TECH NG

INGS

,4%

NON RENEWABLE

AVAILABILITY • EJ Amount of disposable primary energy EFFICIENCY • % Percentage of potential energy transformed into work by the machine EMISSIONS • gCO2 / KWh Grams of CO2 equivalent released for the production of a single kw/h of energy COSTS • €c / KWh Eurocents needed to produce a single kw/h of energy FLEXIBILITY • MINUTES, HOURS, DAYS, SEASONS, YEARS Capability to adequate the production according to the variation of demand

IND

ISI

ING

ILD

COSTS • €c / KWh Eurocents needed to produce a single kw/h of energy FLEXIBILITY • MINUTES, HOURS, DAYS, SEASONS, YEARS Capability to adequate the production according to the variation of demand

VERT

FU RM

,8%

gCo

S RT

ENERGY CHOICE FACTORS (2009) AVAILABILITY • EJ Amount of disposable primary energy EFFICIENCY • % Percentage of potential energy transformed into work by the machine EMISSIONS • gCO2 / KWh Grams of CO2 equivalent released for the production of a single kw/h of energy

ULT

RIC

INGS

INFO

,5%

EFFICIENC 37%

INGS

2/K

8,8

,4%

E UR

NON RENEWABLE

E NR

FLEXIBIL SEASONITY S

EN LE

,3%

3,3

OIC

0,7

ENERGY CHOICE FACTORS (2009)

13 %

IVE

,5%

ING TIS VER OICE CH

4€

WIND 0,2 %

SOLAR 0,1 %

OCEAN 0,002 %

OICE

INCE

GAS 22 %

RS TO ICE FACCHO OF

PR RE RE

NUCLEAR 2 %

INGS

COAL 28,4 %

GIC

ING

TIO

OIL 34 %

ING

INGS

15566 EJ

TIS

OLO

CONSUMERS

VER

ING

gCo

GEOTHERMAL 0,1 %

2030

Kwh

2009

15556 EJ

ICE

FU SE

TEC

RE RE

OIC

VIR

ICE

1980

ONU

TIO

2030

Kwh

2009

8 €c/

2005

CTO

EE N

F SO

ING

D UN

INF

2000

15566 EJ

INF

ING

1995

Kwh

1990

6 €c/

INC

1985

6000 EJ

1980

OICE

R.E. PRODUCTION COMPANIES

CH F

IV NT

20000 10000

Kwh

10 GT Co2

MEDIA

36136 EJ 38025 EJ

48948 EJ

40000 30000

N.R.E. CHOICE FACTOR

HYDROPOWER 2,3 %

CHOICE FLOW

R.E. CHOICE FACTOR

S ION wh ISS EM gCo2/K 50

BIOMASS 10,3 %

KNOWLEDGE FLOW

INF

61718 EJ

80000

60000

6 €c/

41 GT Co2 23 GT Co2

30,5 GT Co2

147 EJ

AVAILABILITY DECREASE

50000

2030

250 ppm

2030

70000

Kwh

2009

20 GT Co2

6 €c/

EAR

ECONOMIC FLOW

2000

30 GT Co2

7400 EJ

19 GT Co2

40 GT Co2

7400 EJ

2009

Kwh

NTA

2005

PRESSURE FLOW

BIOMASS 10,3 %

ING

2000

NTAL

1990

1 GT = 1.000.000.000 Tons 800 EJ

ACTOR

ING

1995

€c/

1990

AVAILABILITY 3.900.000 EJ

R.E. PRODUCTION COMPANIES

RS TO ICE FACCHO OF RE

ONG

PR FU

VIR

1985

TIV

1980

ACTORS AND FLOWS DIAGRAM

492 EJ

INC

1970

100 EJ

PUBLIC OPINION

7,143 mld

200 EJ

1980

OIC

CTO

1960

300 EJ

1950

OIL 34 %

1940

500 EJ

1930

WORLD NON RENEWABLE ENERGIES EMISSIONS 8,31 mld 8,31 mld 674 EJ 501 EJ

2 mld

1920

400 EJ

PR RE RE

U SS

1910

600 EJ

ING

OIC

F SO

1900

700 EJ

MEDIA

Y RG

1890

POPULATION GROWTH ENERGY DEMAND

4,706 mld 277 EJ

OIL OWNERS GOVERNMENTS

N.R.E. CHOICE FACTOR

1880

4 mld

CONSUMERS

R.E. CHOICE FACTOR

1870

6 mld

S RE

1860

8 mld

N.R.E. PRODUCTION COMPANIES

CHOICE FLOW

OIC

300 ppm

10 mld

RESEARCH

KNOWLEDGE FLOW

GOVERNMENTS POOR IN OIL

ECONOMIC FLOW

350 ppm

1850

WORLD POPULATION & ENERGY DEMAND

ONU

READING HIERARCHY

PRESSURE FLOW

400 ppm

13,4°C

ACTORS AND FLOWS DIAGRAM ACTOR

450 ppm

13,6°C

2030

2250 EJ

2000

5 €c/

1995

Kwh

1990

GOVERNMENTS POOR IN OIL

1985

Kwh

1980

8 €c/

READING HIERARCHY

2030

2009

1400 EJ

2005

WIND 0,2 %

2000

SOLAR 0,1 %

1995

OCEAN 0,002 %

1990

Kwh

1985

€c/

1980

14°C 13,8°C

14,2°C

10000

4 €c/

able energy sources because they represent a very interesting and controversial alternative which is definitely going to play a more and more important role in the future. 100 EJ

500 ppm

14,4°C

HYDROPOWER 2,3 %

200 EJ

2 mld

14,6°C

GEOTHERMAL 0,1 %

4 mld

SOLAR

GEOTHERMAL

OCEAN

BIOMASS

HYDROPOWER

WIND

COAL

OIL

NUCLEAR

GAS

0. INTRODUCTION

TAL

R.E. PROD COMPAN

S R E O T C I C A F CHO OF WA

OCEAN 0,002 %

GEOTHERMAL 0,1 %

EE NE RG YS OU RC ES 63

13 % ,6

3, 66

,5%

WIND 0,2 %

HYDROPOWER 2,3 %

BIOMASS 10,3 %

SOLAR 0,1 %

CONTROVERSY

1. CONTROVERSY

1.1 THE CHOICE OF THE ISSUE: SOLAR PHOTOVOLTAIC Since the second step of our analysis, this report, aims to point out a particular controversy and map its deep complexity through an accurate cartography, we had to focus on a single aspect of the issue that could offer a heated debate which could be investigated through digital online researches: a crucial discussion centred upon a single technology or a single social group. We could not take into consideration all the different energy sources though, so we started thinking which one could best fit our examination. Our first idea led us to consider a popular debate such as the one in which biofuels face traditional fossil fuels, but we soon had to drop it because of the width of the topic, the variety of technologies and the age of the discussions. Then we switched to solar photovoltaic energy and discovered it could work: a highly discussed but not inflated issue on a very recent subject

fully available on the internet. Once we got to a promising field we had some difficulties in isolating a precisely defined controversy, though. In fact, the issue we were looking for had to be on one side rich enough to need digital methods to be analysed through but on the other side also simple enough to be answered by a favourable party and a contrary one: a discussion over a single question with several opinions sustaining different pros and cons. We thought of five possible issues and we made an initial global investigation.

Off-Grid The possibility of a home-based photovoltaic energy supply that can give everyone his energetic independence from the traditional electric grid caught intensely our attention for the opportunity of ex-

pansion of photovoltaic technology. After a rather long analysis we were obliged to drop it since it clearly emerged that there is a vivid exchange of ideas among people who stand up for it and discuss over the advantages of this alternative energy system, but there is nobody who highlights also the disadvantages. Moreover, all the sources we could get information from were just simple citizens with a personal interest and a strong faith in alternative energy systems, while any kind of authoritative sources (public institutions, private companies, publicationsâ&#x20AC;Ś) was missing.

Photovoltaic Technology We made a research among the most common photovoltaic modules and panels to isolate a single technology and investigate which are its pros and cons

1. CONTROVERSY

related to who are the main investors and producers. We unfortunately ended up with an infinite list of slightly different models which even took one by one opened a huge foggy universe behind them and we left this path.

Incentives Maybe the most predictable issue related to photovoltaic led us to the interesting field of economics. We wanted to focus on the reason why and which governments have widespread supported production and purchase of solar panels more than any other renewable technology and on the fair aspects of this behaviour. Really attractive at first sight, this topic revealed to be on one hand too much difficult to explore since governmentsâ&#x20AC;&#x2122; affair are not easy to retrace (especially when China, the main solar panel producer, is

involved), on the other hand a dead and gone issue since incentives started a few years ago and ended very quickly.

Chinese Dumping One of the most recent and burning issue we could find was the inquiry by European Community on Chinese companies who export panels in Europe at low prices charged with unfair economical policies and environmental pollution. This issue could have been the most thrilling and unpredictable one for the many connections at economical, diplomatic and environmental level, but we had to give up because of its extreme novelty and hazardous focus on China, not exactly the most welcoming Country for a web-based research.

Photovoltaic Convenience At a less specific level there is a heated debate over costs and benefits of solar photovoltaic. Established that solar light can be considered a renewable energy source there are nonetheless discussions over the environmental sustainability of silicon cells, in addition to the main issues of their economic cost compared to their efficiency. This wide topic did not exclude any of the previous ideas for further focused analysis and offered us an overview structured in a series of focal points on which different fronts at last sustain definite positions.

1. CONTROVERSY

1.2 THE CONTROVERSY OF THE CONVENIENCE Once we had defined the issue to investigate we still had to isolate the precise controversy to concentrate on, because we found three pending areas in which the question of convenience could be highlighted: the economical field, the environmental field and the technological field. Therefore we still had to formulate the question at the base of our project, and in this perspective we started using the digital methods by DMI after the pure Google research. Because of the wideness of the topic we made some researches with different strings according to the different sides of the problems, first comparing the number of results provided by the search engine, then organizing lists of the first hundred of URLs for each query through the tool Harvester and finally comparing these results with the tool Compare Lists. In the end we made a quick overview over all the topic

of the convenience of photovoltaic reading here and there what the sites we found were saying. The three possible fields showed a close network of relationships and a small number of results, so we decided to remain at a superior global level including all the issues as burning points in a bigger discussion. We had finally found our question at the base of the project, and we selected the two queries that had the least results in common to widen our horizons of research.

1. .CONTROVERSY

GOOGLE SEARCH TOOLS

SOLAR OR PHOTOVOLTAIC ENERGY

EXPLORATIVE PRELIMINARY QUERIES

RESULTS EVALUATION

land use

URLS

disposal

cost

beneﬁt

eﬃciency

URLS

environment

URLS

COST AND BENEFITS

Look for sites that talk about:

FIRST REFINED REQUESTS FOR GOOGLE

advantages or disadvantages cost or beneﬁt

cons

emission

pros

URLS

disadvantages

URLS

advantages production pollution

URLS

ADVANTAGES AND DISADVANTAGES

and and

photovoltaic or solar photovoltaic or solar

but but

not thermal not thermal

IN GOOGLE LANGUAGE

advantages|disadvantages photovoltaic|solar -thermal cost|beneﬁt photovoltaic|solar -thermal

1. CONTROVERSY

1.3 THE DEFINITIVE QUESTION

IS SOLAR PHOTOVOLTAIC A TRULY CONVENIENT ENERGY SOURCE?

1. CONTROVERSY

1.4 THE GOAL Our research path was pointed since this moment to the contents of the debate more than on the actor of the opposite fronts. This choice was made first of all because of the nature of our issue: since it didnâ&#x20AC;&#x2122;t appear as a definite controversy but rather as a problematic block of subjects we thought that it would be more interesting to map all these focal points

within the main discussion in order to underline their positioning. In this perspective we individuated a leading thread that could be as general as possible and thinking about photovoltaic power that corresponds to the life cycle of the panels. Moreover, even from these first steps we noticed a particular fragmentation among the protagonist websites, strongly

-1

lacking in authoritative sources and for this reason poor in relationships among themselves. The definitive turning point confirming our direction anyway came just after a little deeper research when gathering URLs we had to face serious problems with the digital tools in our possession.

12 900 00

12 4-

-1 00

-1

12 900 00

12 4-

-1 00

RESEARCH PROTOCOL

2. RESEARCH PROTOCOL

1. Primary research phase

2. Corpus deﬁnition phase

GOOGLE research Advantages/ Disadvantages HARVESTER tool QUERIES COMPARE LIST tool

500 web 100 news 100 discussions 100 blog 100 scholar

The analysis of the corpus (related to the tags) with Google scraper has not yielded results because of too large amount of input and inaccuracy of the results of departure (flaw in the harvester’s urls). The solution was to keep the most useful tag and redial Queries related to tag choices.

Cost/ Benefits

500 web 100 news 100 discussions 100 blog 100 scholar

Manual selection: ALCHEMY API tool

GOOGLE refine

TAGS

definition

GEPHI

0. INTRODUCTION

ANALYSIS

3. ANALYSIS

3.1 FIRST MOVE: HARVESTER AND ALCHEMY API After we established the queries to start the research with through the methods explained before, we began to exploit the potential offered by Google: we decided to take into consideration the basic Search to obtain a general view over how the question is handled within the web, News to discover recent burning themes, Blogs to investigate on the world of bloggers, Discussions to have a look on forum-based debates and Scholar to get a sense of the scientific side of the issue. Basically, we tried to include as many actors of the question as we could. The results we decided to select were the first five hundreds URLs gotten by the basic Search and the first hundred gotten by each one of the other researches, so that we built a corpus of 900 URLs for each one of the two initial queries for a total of 1800 URLs collected by Harvester. Our intention was using such a huge amount

of websites just to make an opening overview of the debate, then picking up the most relevant and going on with a deeper analysis. In fact we obtained just two main pieces of information with the whole initial corpus: on one hand we analysed through Geo IP the geographical provenience of the websites to see which Countries are the most active within the debate, on the other hand we got a detailed representation of the most popular issues and involved entities thanks to the keywords obtained by a huge work with Alchemy API. In this way we managed to reach our first goal, which consisted in discovering what is being told about the convenience of photovoltaic and what are the subjects of the most heated discussions.

3. ANALYSIS

3.2 PROBLEMS WITH THE RESULTS BY HARVESTER In the second step of our research we had to face different important problems that influenced in notable way our successive moves. First, the analysis through Alchemy API provided us a very detailed view on the most discussed fields but articulated in a list of more than 40 thousands tags that we could of course not handle at all. We exploited Google Refine to clean that list and reduce the number of words but it was anyway a too weak intervention. Above all, instead, we discovered that the 1800 URLs gotten by Harvester were completely distorted by a series of errors that could not be repaired either by Refine or Text Wrangler: especially for the results from Google Blogs the tool produced three different URLs for a single result (including the home page of the site the page reached by Harvester belongs to and a not working copy of it), but it also got lots of sim-

ply not working pages. For this reason we realized that the corpus we had built was not suitable for further utilization. We decided instead to keep the tags Alchemy API had provided from those URLs because the errors was widespread in a pretty uniform way, so not particularly influent. What we decided to do then was to exploit those tags, in particular the keywords, to obtain a more focused and more limited corpus of URLs.

energy solar solar power sun photovoltaics solar cell energy fossil fuel renewable wind alternative solar panels us natural gas nuclear electricity energy sources photovoltaic module energy development photovoltaic array oil solar system light energy systems solar systems carbon dioxide electrical energy geothermal energy energy source solar cells global warming sunpower earth energy costs california wind turbines electricity bills windows solar panel christmas efficiency hydroelectricity search engine pollution america british library china florida generation australia roof singapore europe production tidal energy germany

india planet sunlight fuel solar energy systems uk grid hydro power investment wood acid rain solar thermal energy biomass cancer energy conservation k.e. potential energy kinetic energy oxygen information greenhouse gas emissions heat clarence kemp lighting photovoltaic africa japan solar energy advantages environmentalism crude oil natural environment water writing crystalline silicon direct current mexico moving parts united states amorphous silicon google initial cost photovoltaic cells technology watt energy needs environmentally friendly festive party home homeowners pakistan solar power systems credit card heating recycling solar technology

suns tidal power cloud energy supply english-language films peak oil british library direct coal energy crisis livestrong foundation new service other people search british library fuels energy prices federal government green energy hydro initial investment long time privacy policy buying hawaii long run methane power plants texas electricity bill passive solar solar water heaters green swimming arizona canada cell clean energy greenhouse gases mechanical energy new york useful energy carbon footprint ecology gas leak laser power company solar electricity water heating ehow electrical engineering energy resource energy use main disadvantage off-the-grid ontario power grid

south africa spain united kingdom waste adenosine business cheap energy conversion ideal oil gas personal life special relativity thermodynamics twitter weather colorado free energy holidays hydroelectric plants net metering resources solar energy panels solar hot water alliant energy arnold bread bun caffeine centaurous energy advisors llc chocolate truffle christmas controversy cinnamon david gardner dos du electric power energy in physics honeywell italy jeep john d moustache non-renewable resources oil prices violet laser direct sunlight economics electric bill hydro electricity non-renewable energy sources pv solar oven solar power advantages

thermal energy volkswagen air conditioning bio-diesel caribbean energy consumption gasoline guide hydroelectric dams niagara falls otec pollute project solar electric systems solar energy works solar tracker sustainable energy systems tax credits automobile design foreign oil home owners little maintenance mobile phone new jersey nuclear power power generation silicon solar farm solar garden wind farm youtube antoine cesar copyright electronic devices home solar power low maintenance non-renewable sources ohio oil spills photovoltaic panels dc facebook hot water many people natural resources photovoltaic cell problems solar industry windmill yourself electrical power government high cost

led middle east oil companies photovoltaic system real estate solar energy disadvantages solar pv sustainability tax credit ultraviolet worry yahoo! alaska alexander graham bell alternative energy source company cooking electric electric energy electrical grid geothermal power great deal incandescent light bulb light bulbs long term page solar cooker solar power panels wisconsin alternating current battery climate change different types diy solar panel electrical current energy star energy storage heating ventilating and air conditioning high school hong kong new zealand quiet recyclable materials roi safe semiconductor solar collector solar energy technology solar lighting solar modules solar oven sunshine u.s. department of energy us

utility company wave power electrical generator home improvement main advantages passive solar building design petroleum philippines power outage purchasing security solar array solar electric solar radiation want waste management youll discover advertising alternative energy sources alternative sources asia central heating college computer customers electromagnetism energy bill epa excess energy fundamental physics concepts hydropower internet large link marketing methane gas month nasa nuclear fission pennsylvania polluting pv panels savings solar power generation solar powered phone solar water heating solution step utility bills water pollution apple consumer electronics electricity distribution

energy efficient energy meter excess power heater hvac indonesia internal combustion engine international energy agency market metals mississippi non-renewable oil energy power bills power companies power lines pv system rechargeable battery renewable fuels renewable resources samsung solar energy facts solar furnace solar house solar lights solar panels cost solar water storm thanksgiving acoustic energy all rights reserved alternate energy sources appliances carbon centaurous energy advisors choosing combined cycle power plant compact fluorescent lamp cons double kinetic energy dupont efficient energy use electricity demand electromagnetic energy energy category energy coffee energy currency energy flow energy transfer england environment football fresh vegetables general energy category germanium

gravitational potential energy heat energy heat pump helping high energy density honeywell generators energy incentives internal energy dq joules kinetic energy graph life energy life energy process life energy processes make energy metal new york times nonmechanical energy ocean paper photovoltaic systems potential energy formula potiental energy project management sewage treatment solar energy companies solar equipment solar panel systems solar tiles sound wave sunlight energy thermal energy convert useful valence electrons wave affordable ways aid kit essentials air pollution allergens antarctica anymore barack obama bathtub best credit cards best renewable energy blended family holiday calorie tracker chic bun cinnamon spice squash concentrated solar power control urges credit cards cropped sweater curly girls

delaware diy decorations diy festive reindeer dna easy adjustments ehow tech holiday email energy system environmental impact family holiday family holiday letter first solar freezer-friendly cookies gadget guide gingerbread glass good renewable resource great gingerbread houses head-turning hairstyle holiday checklist holiday gifts holiday hostess holiday season holiday travel home solar panels hottest advice humidity factor illinois inexpensive ways institutional sign leftovers light-emitting diode london loose waves los angeles lush lip colors main source management manual shooting modes moustaches movember natural new life non renewable powerstation non renewable resources non-renewable energy ocean thermal energy conversion oil spill oregon overcast overeating peppermint chocolate truffles physics

prices primary energy source proper way renewable objects renewable tidal power saudi arabia science score extra cash sock puppet solar collectors solar distillation solar photovoltaic solar powered garden solar water heater solar wind solarworld tax tips tech toys thin film solar cell threads travel plans tresses usable energy valve video allergies washington water power ways mechanical energy wind energy advantages albert einstein battery backup cadmium cape town chemical energy chemistry emissions community guidelines electric power transmission electric vehicle electrical systems energy companies energy company environmental benefits eskom excess electricity france gases global fight gmat graduate management admission test graduate school harmful health healthy lifestyle

hout bay idaho information technology irs jack harvey knowledge large area light fixture non-renewable resource north america organic matter plant power sources pump resource school science fair science project smog solar batteries solar technologies solar vehicle south korea space sustainable tips vehicle volt 1990s american television series bills brazil commercial solar water concentrating solar power consult convertera solar panel up front cost customer diffuse solar radiation electron entropy finance financial incentives food chain future generations ghana indoor fluorescent light investing kyoto protocol lightning liquid solar cover main disadvantages manage materials michigan

most free energy p-n junction perfect powered garden lights shine solar cell panels solar collector dishes solar deity solar generated steam solar heaters solar heating solar maximum solar oven work solar panel change solar panel pipes solar panels beam solar power grill solar power technology solar powered toaster solar products technologies temperature toilet volkswagen solar panel west virginia wide range alibaba group amazon ammonia answer antarctic athens best answer best way conservation movement conservation of energy dallas diabetes district heating dodge eco-system economical el nino electric current electrical ballast electromagnetic radiation endless supply energy economy energy resources energy security european union expenses experience federal law fluorescence

fluorescent lamp geothermal golf good thing home repair idea ireland kyoto box lg main advantage main reason maine mark wahlberg massachusetts mosses national public radio night time noise pollution nutrition pacific ocean personal computer photoelectric effect photovoltaic solar cells power power source qiana rice silk solar cookers international solar electric power solar installation spark sulphur dioxide tannery tax breaks time utility grid will farrell wind generators residential feed in tariff low cost grid parity construction electric car cold input subsidies balance sheet good news polymer wafer electrode

3. ANALYSIS

3.3 MANUAL SELECTION OF THE DEFINITIVE KEYWORDS Since the amount of keywords was way too larger to use we had to select the most important ones. Reading the list we realized that a choice based exclusively on criteria consisting in frequency of occurrence and automatically attributed relevance would not be useful because of the lack in a relationship with the context. We actually wanted to isolate words that could point to a controverted question, words that could be representative of side interesting issues and above all words that could be considered measurers of positive or negative aspects, so we opted for a manual component within the choice. First of all, then, we fixed a minimum of count (10 for the tags by Google Search, 5 for the other fields) and we made a first basic selection; then we did the same with the parameter of relevance up to 0,3 at least; in the end we read all the remaining words and manually decided which ones could point to

interesting subjects, applying a manual refining for composite terms and synonymous. We therefore obtained a corpus of 152 different keywords (71 from Basic Search, 53 from Blogs, 39 from Discussions, 43 from News, 52 from Scholar, with obviously some tags in common) and gathered them in 6 categories following their typology: according to their context we grouped them in “Economics”, “Energy Sources”, “Environment”, “Solar Energy”, “Solar Panels” and “Other” for the few that didn’t fit in any of the categories before. In this way we had defined a small but very focused corpus of fundamental keywords to use both for producing a corpus on URLs and for the analysis of their content in terms of positive and negative aspects of the controversy. In addition, we selected also the most important names of Countries that appeared among the entities provided by Alchemy API to confront with the geographical location of the websites.

3. ANALYSIS

TAGS MANUAL

SELECTION

>40.000 TAGS

CORPUS

ENTITIES &

COUNTRIES

SELECTION

according to: - count > 10 - relevance > 0,3 - tag considered measurer - tag related to burning points

according to: - count > 10

152 KEYWORDS

SELECTED

Discarding tag that do not meet those parameters

3. ANALYSIS

S RCE SOU

lm -fi in th io nium t ita um t acu r v afe ow ve w ind ati w tern al al uel icity co ssil f lectr fo droe e h y than a s me ural g nat lear nuc oil peak able renew e resourc sources water wind balance sheet banking business cheap crisis econo elec mic elec tric bill ene tricity exp rgy bil bill fee ensiv l fin d-in e gre ance tariff gr at h oss dea incigh c ma l in e os rg in iti nti t in in ves al c ves o ves tm ost t e c ors nt st

yn a

al tic eu n ac tio m za i ar y til ph -ra tery ty u x at aci n b p e tio ca harg erva tion c ns mp n co nsu sio co nver t co ren cur -ac ent dc velopm rent cur de t c dire ct limit dire ric car nd elect ricity dema elect needs energy excess generation generator grid grid parity input light mppt net m off g etering pro rid pumduction sh p sp ort-ci st ectro rcuit su orag scopy vo ppl e a ltag y b mo e c a n d rp h c ad g ou co oati miu ap s ry nst ng m s r t al uct lin io e n

o - t w rke a e m ric p oi ngs s r avi idie s bs su x edit ta x cr ta de t cost al tra -fron capit up ture ven cer ide can on diox rint carb on footp carb clean change climate cloud cold earth emissions environment environmental environm global w entally green arming green poll house g ases rec ution sus ycling t wa aina we ste ble bio athe dn tec r go a hnol og h od y la olid ne lo w ay ws n lo g ng te tim rm e

SOLAR PANELS

OT HE R

ss ce ro ip sk al c u2o chr ht c o g cz ts nli cz iode t su g d ec zin dir y gla ed di uble sitiz do e-sen cy dy cien effi ctrode e ele trolyt elec tron elec rimental expe ion funct ium german glass heterojunction home homeowners led maintenance material metals oxyge p-n n ph junction o pho toelectr ic ef po ton fect po lymer qu tenti re antu al ro side m si of ntial s lico s ol a n s ola r ra th pac r tr dia e rm e ack tion er od

BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

ENVIRONMENT

SOLAR ENERGY

EC ON OM IC S

co si nv lic ef ers on fic io i n amma enc t or er y ph ial ou lo lig s w h -c t cr cur ost ys re ta nt vo llin el ltage e po ctroe lym n w er af e d er ge lec iod rm tro e a d fu niu e bi q nc m ot ua tio ec n n hn tum o di co logy re at ct ing lim pn i ju la t dy b nc w e t a ph -s n io ar en d g n m si ap ac tiz eu ed b t el an ical ec ki tro ng he finalyte te p nc ex roju hot e pe n on rim cti en on ta ph ot sp o mp l oe ec x pt y le tro ge c sh tric sco n or ef py t- fe c th irc ct in ui -fi t en lm vir o ex nm tio re pen ent ne si w ve va ab cu le so la d um r t cr a tit ack c ca ani er dm um iu cz oc cu m hr 2 al cz o sk i p d ts ro na ce x- ss ra y

re ne w m abl ar e si ket lic o w n de ve sp ind lo a p c bu me e si nt ne s g s ge t rid ne ra ra de pr ption od ri ec uc ce on tio o n su mic in c pply v na est lea tu me n fo ral nt ss ga il s fu su wa el bs fe ef id r fic ie i s su stoenc st ra y cr ain ge cl a ystaable im lte ll a r in gr te nat e os ch ive s an m ta ar ge en x cr gin er ed gy it em bill co ba l issi al la ow on co nce -co s ns s st u h co mp eet nv ti er on am sio o ea n ve i rph rth nt nv o ca h ure es us pa om c tor ci e ap s ty o it ut wn al i gr liza ers go id p tion od ar ne ity w s w w ind at e re ne t r w ax a ho ble m e so gr ur id ce s ba ligh tte t g ry su ree st r n al ain oo te a f rn ble a ch tive ar g en gen ear e vir er th o at ef nm or fi e fo cie nt ss nc cl il y im fu a co te c pumel ns ha p co e n ns rva ge el um tio ec pt n tr io ca i rb we c c n on a ar di the o r hy e c xid dr co he e oe n ap le om ct ic ric ity le in iti co d co al ld nv co er st de s do ve i ion ub lop np el le m ut ec gl en tr az t ic in po ity b g llu ill ti cl on ou d

ab w le in al te lig d rn h t m ativ ar e k s bu ilic et fo sin on ss es en il fu s vir w el on ate m r e ef g nt in fic rid i ve e p s nc de rod tme y ve uc nt l ge opmtion ne e ra nt t en nuc ion er le g ar su st y bi st ora ll a g co ina e ns c ble um le a p n w tio i n co lo do n ns w- w tr co el cry uct st e ca ct sta ion rb ric llin o it e nan di y bi tu ox ll ra ide sa l ga vin s em e gs i ar e lo ss th gl ne ng ion ob rg te s al y n rm w ee a d th rmi s in ng -fi di p ch lm re ol ea ct lu p cu tio r n am ren or co t ph al ca en ex ous rb vir on ces on f gl s m en in ootpass ta itia ri lly l nt fr co m ien st e d hi tha ly gh n co e go s od d t lo ne iy n gr g t ws ea im t e pe de ak al oi l

re n ew

ab fo w le ss in il d fu lig el re pr ht so ice u al si rce te lic rn on at iv ro e of in ma grid ve r in stm ket ce e n n n tiv t ef ucl es na fic ea tu ien r ra c l y re c gas si le de an co n ns ho tia um lid l p ay su tion s pp en poavin ly er ll gs gy uti o p ne n en ote eds gr e nt ee nh rgy ial ou w bil m s a l ca ain e ga ste rb te se on na s el di nce ec ox tr id ic e b ea ill co wea rth nv th er er ex sion t gl amax cces ob o re s al rp di w ho t ar u co s mi s ns to ng e r cr rva age ys ti ta on m lline et a th che ls in ap hy in of film dr it f g oe ial rid fe le co di ed- ctri st re in ci n ct t ty cl et cu arif im m rr f at et en e er t ch in an g cr ge is is w ro in i do so w la en d r vir up ra clo iy on -f dia ud ro ti m nt on en ta c co lly an st f c l rie e ca ong nd r rb l te ly on ow rm fo -co o hi tpr st gr gh int en id co vir re par st on cy it m el ec en p cli y tr ta ea ng ic l k d it im o th ire y de pa il er ct m ct m su a od n nd yn lig am ht ic s

re n

3. ANALYSIS BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

3. ANALYSIS

3.4 MOST RECURRING KEYWORDS AMONG THEIR CATEGORIES First of all, at the first glance of the precedent visualization it clearly emerges that the division among categories underlines the domination of tags concerning “Solar Energy”, “Solar panels” and then “Economics”, which reflects the fact that the debate over photovoltaic is mainly around technological questions and economical aspects, in fact the widest subjects and the most discussed ones. As it is displayed in the following graphics, since we understood from the beginning that the debate is mainly articulated in web pages led by single citizens, the high frequency of keywords concerning panels and energy highlights the discussion over advantages and disadvantages of a home-based technology in terms of relationships with the standard electric grid and operating life of the plant. For the same reasons, the economical issue is faced from the perspective of homeown-

ers interested in governmental incentives, prices and the present market situation. Exceptions to this main trend are in a light way results by News, which of course focus mainly on the economical features, and more evidently the ones by Scholar, which show a technical debate over the chemical and electronic components of solar panels.

3. ANALYSIS

renewable

ENERGY SOURCES

wind fossil fuel light price rresource

silicon alternative roof market investment ent incentives ntives

ECONOMICS

efficiency clean savings

SOLAR PANELS

SOLAR ENERGY

grid

residential consumption supply

pollution energy needs potential t waste greenhouse gases carbon dioxide

BASIC WEB MOST FREQUENT TAGS DIVIDED AMONG CATEGORIES

ENVIRONMENT

OTHER 33

3. ANALYSIS

renewable

ENERGY SOURCES

wind light alternative market silicon business fu fossil fuel water grid

investment investm

SOLAR ENERGY

environment

product production development generation

efficiency

energy bill sustainable clean window

low-cost st

construction crystalline carbon dioxide

ECONOMICS

Earth

SOLAR PANELS

ENVIRONMENT

OTHER 34

BLOGS MOST FREQUENT TAGS DIVIDED AMONG CATEGORIES

3. ANALYSIS

wind

ENERGY SOURCES

water tax renewable home grid sources light battery

SOLAR ENERGY

green sustainabl sustainable

roof alternative

charge

Ear Earth environment

ENVIRONMENT

SOLAR PANELS ECONOMICS

generator efficiency

climate change

DISCUSSIONS MOST FREQUENT TAGS DIVIDED AMONG CATEGORIES

3. ANALYSIS

renewable

ECONOMICS market

silicon wind space development

business ness

ENERGY SOURCES

grid

trade de

generation

price

production clean natural gas

SOLAR ENERGY

SOLAR PANELS

ENVIRONMENT

OTHER

sustainable

climate change NEWS MOST FREQUENT TAGS DIVIDED AMONG CATEGORIES

3. ANALYSIS

silicon conversion

SOLAR PANELS

efficiency material amorphous light

crystalline electron polymer wafer

current

low-cost

voltage

SOLAR ENERGY

ECONOMICS

OTHER

SCHOLAR MOST FREQUENT TAGS DIVIDED AMONG CATEGORIES

ENVIRONMENT ENERGY SOURCES 37

3. ANALYSIS

3.5 EIGHTY URLS: THE DEFINITIVE CORPUS Once we assembled our instrument for the new research, we thought of which digital tool we could use to produce the corpus of web pages. We started with Google Scraper in order to find out the sites with highest occurrence of our selected tags trying to save our initial work that had provided 1800 URLs, but soon we had to face another crucial problem: Scraper in fact, apart from taking everlasting time for its work depending on the high number of keywords and the huge number of URLs, revealed to fail when Google itself identified our research as a web robot and consequentially blocked it. We had to definitively abandon our initial problematic huge corpus of URLs and to think of an alternative route. We decided to go back to the couple of initial Google queries and make again a web research, this time exploiting our keywords to integrate the two queries. The

goal of this choice was clearly making a sort of alternative Scraper, looking for the web pages most containing our selected tags with the further advantage of benefitting from the rank of the results offered by Google. We then structured our new research in the following way: we combined each one of the two starting query with the words from each one of the six categories of tags, making a total of 12 queries. We took into consideration just the first ten results for each query and compared them at first two lists by two according to their categories, then cross-checking them all together. What we selected were first of all the resultant URLs that compared in more than one query, than we picked the others according to their rank from the first downward till we completed our definitive corpus made by 40 URLs from Google Search, 10 from Blogs, 10 from Discussions, 10 from

News and 10 from Scholar for a total of 80 URLs. In this way we managed to get a handy corpus focused at its best on the burning issues balanced among the different fields of Google according to their importance.

3. ANALYSIS

ENERGY SOURCES ENVIRONMENT ECONOMICS

SELECTED TAGS

SOLAR ENERGY

advantages|disadvantages photovoltaic|solar -thermal

GOOGLE

SOLAR PANELS OTHER

2 NEW QUERIES

12 CATEGORISED QUERIES

> 32 words (limit of Google)

< 32 words each

10 URLS from each FOCUSED QUERIES

FINAL CORPUS

RESULTANT URLs

COMPARISON

1. between same categories 2. with other categories

FINAL CORPUS

SELECTION 1. occurrence > 1 2. according to rank

Same protocol with Blogs, News, Discussions and Scholar

40 URLS from BASIC SEARCH 10 URLS from BLOGS 10 URLS from DISCUSSIONS 10 URLS from SCHOLAR 10 URLS from NEWS

BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

3. ANALYSIS

· advantagesanddisadvantagessolarenergy.com/the-disadvantages-of· solar-energy-weather-and-location/ · cleantechnica.com/2011/09/26/westinghouse-solar-introduceslow-cost-all-in-one-home-solar-power-kits/ · cleantechnica.com/2012/12/11/wind-solar-storage-could-power-full-electric-grid-cost-e ·ffectively-99-9-of-the-time-by-2030-report/ · en.wikipedia.org/wiki/Mitigation_of_peak_oil · greenliving.nationalgeographic.com/advantages-disadvantages-solarpowered-homes-2865.html · homeimprovement.superpages.com/lighting/advantages-of-solar-lighting.html · insight.milliman.com/article.php?cntid=8052 · library.thinkquest.org/20331/types/solar/advant.html · life.gaiam.com/article/whats-it-going-cost-me-go-solar · peakoil.com/alternative-energy/middle-east-beginning-to-embrace-solar-energy/ · solarleasedisadvantages.com/ · wiki.answers.com/Q/What_are_the_advantages_and_disadvantages_of_solar_power · all-recycling-facts.com/solar-energy-advantages-disadvantages.html · ata.org.au/forums/topic/2265 · benefits-of-recycling.com/advantagesofsolarenergy/ · chm.bris.ac.uk/webprojects2003/ledlie/advantages_of_solar_energy.htm · clean-energy-ideas.com/articles/advantages_of_solar_power.html · conserve-energy-future.com/Advantages_SolarEnergy.php · conserve-energy-future.com/Disadvantages_SolarEnergy.php · doityourself.com/stry/disadvantages-of-solar-power#b · eco-info.net/ · ehow.com/info_8473702_advantages-grid-connected-photovoltaic-systems.html · energyandcapital.com/ · energymatters.com.au/renewable-energy/solar-power/grid-connected-systems/ home-grid-faq.php · findsolar.com/index.php?page=rightforme · forbes.com/sites/uciliawang/2012/06/18/dows-solar-shingles-found-their-first-home-in-california/ · greenelectricityguide.com/the-benefits-and-disadvantages-of-renewable-energy-resources · homedepot.com/webapp/catalog/servlet/ContentView?pn=KH_BG_ EL_Solar_Power&storeId=10051&langId=-1&catalogId=10053 · ilsr.org/solar-grid-parity-101/ · millionsolarroofs.com/advantagesofsolarenergy.html · powersourcesolar.com/5151/index.html · scottmadden.com/insight/407/Solar-Photovoltaic-Plant-Operating-and-Maintenance-Costs.html · solarcity.com/residential/solar-pricing.aspx · sunrunhome.com/solar-for-your-home/guide/advantages/ · sunrunhome.com/solar-lease/cost-of-solar/ · thedailygreen.com/environmental-news/latest/solar-panel-recycling-460810 · udel.edu/udaily/2013/dec/renewable-energy-121012.html · wholesalesolar.com/gridtie.html · wholesalesolar.com/StartHere/GRIDINTBallparkCost.html · wholesalesolar.com/StartHere/OFFGRID/OFFGRIDCalculator.html

· advantagesanddisadvantagessolarenergy.com/ advantages-and-disadvantages-of-solar-energy-going-off-the-grid/ · blog.heliopower.com/ · earthfourenergy.blogspot.it/2012/11/the-advantages-and-disadvantages-of.html · green.blogs.nytimes.com/2012/12/11/solar-installations-surge-onlower-costs-and-government-support/ · homeenergy.com/ · globalissues.org/news/2012/12/14/15521 · greenlivingtips.com/articles/advantages-of-rooftop-solar-power.html · renewablegreenenergypower.com/advantages-and-disadvantages-of-solarphotovoltaic-quick-pros-and-cons-of-solar-pv/ · thegreenerhome.com/eblog/whatever-happened-to-low-cost-solar-power/ · udel.edu/udaily/2013/dec/renewable-energy-121012.html · answers.yahoo.com/question/index?qid=20080707101630AAzDoHR · answers.yahoo.com/question/index?qid=20081216144143AAobcIx · askville.amazon.com/real-cost-putting-solar-panels-house/AnswerViewer.do?requestId=127043 · doityourselfchristmas.com/forums/showthread.php?23298-Go-Green-Go-Solar-The-Advantages-of-Solar-Power · in.answers.yahoo.com/question/index?qid=20120329052542AAJv4P0 · ths.gardenweb.com/forums/load/energy/msg0209522418015.html?10 · greenerpeople.com/forum/greener-energy/259-solar-vs-wind-energy.html · groups.google.com/forum/?fromgroups=#!topic/google.finance.3025529/Pb19lArdNpo · groups.google.com/forum/?fromgroups=#!topic/soc.culture.indian/nLmjPYCBwDc[1-25-false] · groups.google.com/forum/?fromgroups=#!topic/uk.rec.sailing/-jEOn9l4X5c · articles.timesofindia.indiatimes.com/2012-12-16/coimbatore/35850119_1_solar-plants-solar-energy-solar-power · ntdtv.org/en/news/science-technology/2012-12-11/grid-parity-and-net-metering-hotsubjects-for-israel-s-solar-.html · seekingalpha.com/article/1060131-the-buy-side-of-solar-finally-coming-public · seekingalpha.com/article/1067681-biggest-reason-why-first-solar-is-a-short-it-s-the-cost-stupid · thinkprogress.org/climate/2012/12/16/1320311/get-ready-utilities-solar-is-coming/?mobile=nc · cleanenergyauthority.com/solar-energy-news/efficiencies-to-drive-cost-down-121612 · dailyrecord.us/Story.aspx?id=14657&date=12%2F17%2F2012 · equities.com/news/headline-story?dt=2012-12-16&val=832844&cat=energy · onlinetes.com/first-solar-thin-film-module-121612.aspx · utilityproducts.com/news/2012/12/16/towards-a-low-carbon-future.html · ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1486627&url=http%3A%2F%2Fieeexplore.ieee.org% 2Fxpls%2Fabs_all.jsp%3Farnumber%3D1486627 · ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4845579&url=http%3A%2F%2Fieeexplore.ieee.org% 2Fxpls%2Fabs_all.jsp%3Farnumber%3D4845579 · onlinelibrary.wiley.com/doi/10.1002/adma.200501717/abstract · onlinelibrary.wiley.com/doi/10.1002/pip.533/abstract · nature.com/nature/journal/v395/n6702/abs/395583a0.html · nature.com/nmat/journal/v4/n9/full/nmat1457.html · sciencedirect.com/science/article/pii/0379678787901050 · sciencedirect.com/science/article/pii/S0040609008013953 · sciencedirect.com/science/article/pii/S0927024802000582 · sciencemag.org/content/315/5813/798.shortv BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

3. ANALYSIS

GLOBAL COUNTRIES GEOLOCALIZATION Canada

United Kingdom

United States

Europe China

India

Singapore

Australia

42 ng

Pa ki st an In di a Ch in a Si ng ap or e N or th Ko re a Au st ra Ja lia pa n

Ira

do Sp m Fr ain a Ge nc rm e an It y So Gre aly ut ec hA e fr i Is ca ra el

ite

na d

Un Me ite xico dS ta te s

3. ANALYSIS

BASIC WEB GEOGRAPHICAL COMPARISON

TAG OF COUNTRIES GEO LOCATED IPs

3. ANALYSIS

SCHOLAR GEOGRAPHICAL COMPARISO

Ch in a

ud iA Sa

Ki ng d Un

ite

do m

es at dS t ite Un

bi a

TAG OF COUNTRIES GEO LOCATED IPs

44 ut

pp in es hK or Au ea st ra lia Ja pa n

ili

Ph So

ia in

In d

ss ia

ic a

Ira

hA fr

do m Fr an ce Ge rm an y Ita ly

Un i

Ca n

te s

M ex i dS

Un i

3. ANALYSIS

BLOG GEOGRAPHICAL COMPARISON

TAG OF COUNTRIES GEO LOCATED IPs

in a

Ta iw Au an st ra l Ja ia pa n

di a Ch

d Sp om ai n G Cz erm ec an hR I y ep tal u y Gr blic ee ce Sa ud iA ra bi a

ite

na d Ch a ile

te s

ite

3. ANALYSIS

NEWS GEOGRAPHICAL COMPARISON

TAG OF COUNTRIES GEO LOCATED IPs

46 nd

Ze la

In di a Ch Si in ng a ap o Th re Ph ai l a il n Ho ippi d So ng nes ut Ko hK ng Au ore st a ra Ja lia pa n

ng do Sp m ai n Ge rm an Ita y ly

ite

Ca na

Un Me ite xic dS o ta te s

3. ANALYSIS

BLOG GEOGRAPHICAL COMPARISON

TAG OF COUNTRIES GEO LOCATED IPs

3. ANALYSIS

3.6 MANUAL EVALUATION OF THE POSITIONING OF THE TAGS With the definition of a list of URLs we finally obtained our sample of online debate over photovoltaic energy. As specified in the introduction we pointed our research to the contents of the discussion rather than on its actors, so we deepened the analysis of the websites through the selected keywords. Those were actually picked for their quality of being measurers of focal points and in this phase we exploited them to investigate how our speakers face the issue. Our intention was to cross-check each site with the tags of the branch of Google we got it from (News, Blogs, Discussionsâ&#x20AC;Ś) but Scraper again couldnâ&#x20AC;&#x2122;t help us because of its limits, so we looked for alternative ways and this time we found a vital support in Google Bar Lite. This little tool permitted us to discover the frequency of every single word within the single site and its position within the sen-

tences: apart from offering a view over the weighed presence of the keywords, it let us analyse the context and the role of them. For this reason we started reading carefully each one of the URLs of the corpus giving a positive, neutral or negative value (+1, 0, -1) to each tag according to the main question at the base of the project. In this way we highlighted how the sites of the corpus handle specific topics.

3. ANALYSIS

IS A DETERMINED TAG USED FOR EXPLAIN AN ADVANTAGE OF A DISADVANTAGE OF THE SOLAR ENERGY?

CORPUS

GOOGLE BAR LITE

To higlighs the tags wich appears in the contents of the current url

TAGS

URLS CONTENTS LECTURE and TAGS DEFINITION

TAG

DEFINITION

0 -1

POSITIVE VALUE: In the url contests the tag is used with positive meanings for the deﬁnition of solar energy

NEUTRAL VALUE: In the url contests the tag is used with negative meanings for the deﬁnition of solar energy

NEGATIVE VALUE: In the url contests the tag is used with neutral meanings for the deﬁnition of solar energy

TAG LIST List of tag with a connected number of evaluation

alternative

wind

weather

waste

up-front p cost

tax credits

supply pp

storage g

solar

silicon

savings g

roof

resources

residential

renewable

recycling

price

potential

pollution

peak oil

off grid g

nuclear

net metering g

needs

natural gas g

metals

market

maintenance

long g term

light g

initial cost

incentives

high g cost

heart

grid

g greenhouse gases g

g global warming g

fossil fuels

feed-in tariff

excess

environmentallyy friendlyy

environmental impact p

energy bills

electricityy demand

electric bill

efficiencyy

earth

DIY

crisis

conversion

conservation

cloudyy

climate change g

clean

cheap p

carbon footprint p

carbon dioxide

amorphous p silicon

3. ANALYSIS

BASIC WEB TAG USED TO HIGHLIGHT AN ADVANTAGE

COUNT OF TAG USAGE

TAG USED TO HIGHLIGHT A DISADVANTAGE

50 business

coal

wind

weather

water

wind

water

sustainable

storage

savings

residential

renewable

production

pollution

off the grid

nuclear

market

low cost

investment

industry

high cost

good news

glass global warming

sources tax

generation roof

fossil fuel

excess

environment

renewable

pollution

lgiht

LED

input

energy bills

emissions

initial cost

electricity bills

grid

efficiency

earth

developement

consumption

home

green

generator

erath

environment

electricity car

electricity bill

clean

cheap

carbon footprint

cleaning

economic

development

china

chinese

conversion

consumption

cold

cheap

charge

DISCUSSION carbon dioxide

COUNT OF TAG USAGE

carbon dioxide

TAG USED TO HIGHLIGHT A DISADVANTAGE

alternative

TAG USED TO HIGHLIGHT AN ADVANTAGE

battery

alternative

3. ANALYSIS

BLOG

amorphous

thin film

silicon

photon

p-n junction

material

low-cost

heterojunction

environment

electron

electrolyte

efficiency

dye-sensitized

CZTS

current

conversion

biotechnology

wind

trade

storage

space

silicon

renewable

production

prices

nuclear

market

investment

industry

grid

generation

fuel prices

fuel

fossil fuel

emissions

efficiency

economic

development

conversion

consumption

coal

clean

business

3. ANALYSIS

NEWS TAG USED TO HIGHLIGHT AN ADVANTAGE

COUNT OF TAG USAGE

TAG USED TO HIGHLIGHT A DISADVANTAGE

SCHOLAR

0 5 10 15 20 25

52 price initial costs market cheap needs electric bills high cost energy bills investment offgrid savings electricity bills tax credits up-front cost business consumption economic fuel prices incentives low cost peak oil solar supply trade recycling pollution waste weather cloudy carbon dioxide environment clean cloud emissions cold global warming climate change carbon footprint environmental impact renewable chinese china potentially light excess storage consumption grid battery conversion offgrid production supply consumption developement electricity demand input efficiency roof residential cleaning maintenance silicon amorphous electrolyte home manteinance metals potential space wind fossil fuels renewable coal light peak oil natural gas alternative sources nuclear

price i savings cheap incentives market offgrid electric bills investment needs industry business electricity bills energy bills initial costs low cost peak oil price tax credits consumption crisis developement economic feed-in tariff high cost clean environment pollution carbon dioxide recycling earth global warming emissions sustainable greenhouse gases cold waste climate change renewable environmentally friendly green carbon footprint renewable electricity car chinese long term alternative biotechnology good news heart grid light storage consumption supply developement generation net metering battery production conversion excess charge conservation current electricity demand electric car generator offgrid g efficiency maintenance roof residential potential material LED metals silicon DIY home amorphous cleaning dye-sensitized electrolyte glass heterojunction p-n junction photon thin film renewable wind alternative fossil fuels light resources nuclear coal water natural gas fuel sources

3. ANALYSIS

85 80 75 70 65 60 55 50 45 40 30 25 20 15 10 5 0

ECONOMICS ENVIRONMENT OTHER SOLAR ENERGY SOLAR PANELS SOURCES

3. ANALYSIS

TALKS ABOUT ADVANTAGES TALKS ABOUT DISADVANTAGES COUNT OF SELECTED TAGS FOUND IN THE SITE

7 8 9101112131415161718 192021

22 23 24 25 26 27 28 29 30

31 32 33 34

36 37

BASIC WEB -1,0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

• advantagesanddisadvantagessolarenergy.com • eco-info.net • doityourself.com • ilsr.org • solarleasedisadvantages.com/ • nsight.milliman.com • chm.bris.ac.uk • energymatters.com.au • ata.org.au • peakoil.com • solarcity.com • greenelectricityguide.com • conserve-energy-future.com • millionsolarroofs.com • cleantechnica.com • ehow.com • greenliving.nationalgeographic.com • scottmadden.com • life.gaiam.com • thedailygreen.com

1,0

21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

• library.thinkquest.org • clean-energy-ideas.com • wholesalesolar.com • en.wikipedia.org • homedepot.com • wholesalesolar.com • udel.edu • energyandcapital.com • wiki.answers.com • all-recycling-facts.com • sunrunhome.com • forbes.com • cleantechnica.com • powersourcesolar.com • wholesalesolar.com • conserve-energy-future.com • sunrunhome.com • benefits-of-recycling.com • findsolar.com

3. ANALYSIS

1 TALKS ABOUT ADVANTAGES

8 9

BLOG

TALKS ABOUT DISADVANTAGES COUNT OF SELECTED TAGS FOUND IN THE SITE

-1,0

1 2 3 4 5 6 7 8 9 10

1,0

• advantagesanddisadvantagessolarenergy.com/advantages-and-disadvantages-of-solar-energy-going-off-the-grid/ • blog.heliopower.com/ • earthfourenergy.blogspot.it/2012/11/the-advantages-and-disadvantages-of.html • green.blogs.nytimes.com/2012/12/11/solar-installations-surge-on-lower-costs-and-government-support/ • homeenergy.com/ • globalissues.org/news/2012/12/14/15521 • greenlivingtips.com/articles/advantages-of-rooftop-solar-power.html • renewablegreenenergypower.com/advantages-and-disadvantages-of-solar-photovoltaic-quick-pros-and-cons-of-solar-pv/ • thegreenerhome.com/eblog/whatever-happened-to-low-cost-solar-power/ • udel.edu/udaily/2013/dec/renewable-energy-121012.html

7 8 9

SCHOLAR -1,0

1 2 3 4 5 6 7 8 9 10

1,0

• ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=1486627&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D1486627 • ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4845579&url=http%3A%2F%2Fieeexplore.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D4845579 • onlinelibrary.wiley.com/doi/10.1002/adma.200501717/abstract • onlinelibrary.wiley.com/doi/10.1002/pip.533/abstract • nature.com/nature/journal/v395/n6702/abs/395583a0.html • nature.com/nmat/journal/v4/n9/full/nmat1457.html • sciencedirect.com/science/article/pii/0379678787901050 • sciencedirect.com/science/article/pii/S0040609008013953 • sciencedirect.com/science/article/pii/S0927024802000582 • sciencemag.org/content/315/5813/798.short

3. ANALYSIS

4 5

6 7

8 9

DISCUSSIONS

TALKS ABOUT ADVANTAGES TALKS ABOUT DISADVANTAGES

-1,0

1 2 3 4 5 6 7 8 9 10

1,0

COUNT OF SELECTED TAGS FOUND IN THE SITE

• answers.yahoo.com/question/index?qid=20080707101630AAzDoHR • answers.yahoo.com/question/index?qid=20081216144143AAobcIx • askville.amazon.com/real-cost-putting-solar-panels-house/AnswerViewer.do?requestId=127043 • doityourselfchristmas.com/forums/showthread.php?23298-Go-Green-Go-Solar-The-Advantages-of-Solar-Power • in.answers.yahoo.com/question/index?qid=20120329052542AAJv4P0 • ths.gardenweb.com/forums/load/energy/msg0209522418015.html?10 • greenerpeople.com/forum/greener-energy/259-solar-vs-wind-energy.html • groups.google.com/forum/?fromgroups=#!topic/google.finance.3025529/Pb19lArdNpo • groups.google.com/forum/?fromgroups=#!topic/soc.culture.indian/nLmjPYCBwDc[1-25-false] • groups.google.com/forum/?fromgroups=#!topic/uk.rec.sailing/-jEOn9l4X5c

1 2

7 8

NEWS -1,0

1 • articles.timesofindia.indiatimes.com/2012-12-16/coimbatore/35850119_1_solar-plants-solar-energy-solar-power 2 • ntdtv.org/en/news/science-technology/2012-12-11/grid-parity-and-net-metering-hot-subjects-for-israel-s-solar-.html 3 • seekingalpha.com/article/1060131-the-buy-side-of-solar-finally-coming-public 4 • seekingalpha.com/article/1067681-biggest-reason-why-first-solar-is-a-short-it-s-the-cost-stupid 5 • thinkprogress.org/climate/2012/12/16/1320311/get-ready-utilities-solar-is-coming/?mobile=nc 6 • cleanenergyauthority.com/solar-energy-news/efficiencies-to-drive-cost-down-121612 7 • dailyrecord.us/Story.aspx?id=14657&date=12%2F17%2F2012 8 • equities.com/news/headline-story?dt=2012-12-16&val=832844&cat=energy 9 • onlinetes.com/first-solar-thin-film-module-121612.aspx 10 • utilityproducts.com/news/2012/12/16/towards-a-low-carbon-future.html

3. ANALYSIS

3.7 THE ACTORS AND THEIR NETWORK OF RELATIONSHIPS With the definition of a list of URLs we fAs for the actors of the debate, instead, we wanted to build a network of relationships to explore their mutual influences and their common inspirations. A big problem at the base of this was represented by the fact that most of our URLs are single pages regarding photovoltaic energy that can be found just at a certain depth within websites regarding different subjects. For this reason we first recurred to the tool of Link Ripper, since it obtains outgoing and incoming links making reference to the single web page. The results were really disappointing, because not only anyone of our URLs reported to no one of the others, but also they had no external links in common (if we exclude twitter.com). We then gave a try with Navicrawler even if it didnâ&#x20AC;&#x2122;t really match our needs since it works just with hosts, basically pages that we donâ&#x20AC;&#x2122;t

know what they talk about. Once again, the results were not satisfying because of several URLs with no connections, but at least we were able to build a basic network of relationships that we geographically located through Geo Ip.

w w w. w

le sa le cl so ea .n la w a n tio r w t e w. ch .com be nal n ic ne ge a. o fit s- gra com ph of -r ec ic.c om y en clin g. .w lib co ik ra m ip ry .th edi a. in or kq ue g st w pe w . w. ak org cl oi lif ea l.c e. nom w en gai w a e m w. rg .c co yo ns id ea m er w s w ve . c w -e om ne .ata rg .o r yg. w w w futu au w. re en ww . .e er co com gy -in m at fo te . rs net w . co w w w m w .a w. .for be u ho s. m co ed ep m w o w w. t.co w e m w w. how w w .c w. sol om ar su ci nr un ty.c om ho m w w e .c w. w om w th w. ed i l ai s r b lyg .o lo ea rg g re rt en hf .he lio ou .c om po gr ren w e ee er .c n. rgy. o bl w og blog m w s. s w. gr nyt pot w .it im ee w w. th nliv es.c eg in om g re en tips .c er om ho w m w e. w w. co gr ww m ee .u de w ne w l.e rp w. d e s cl ea eek opl u e. ne in co ga ne m lp rg ha ya .c ut om h th in orit kp y.c ro w om w w. gre ss on .o li w nete rg w w s. w co w. w.n at sc m ur ie n e w . c c ed w om w. sc irec t.c ie nc o em m ag .o rg ng

ivi

gr ee

BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

3. ANALYSIS

BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

CONCLUSIONS

LI F

/R EC YC LI N G

AT I

LA TI

ST AL

DI SP OS AL

UC TI

SO U

PA N

-0 29 4-1 31 -1 00

4. CONCLUSIONS

CONTROVERSIES

! !

000 129-0 1314-

4. CONCLUSIONS

4.1 GENERAL OVERVIEW ON MAIN FOCAL POINTS At the end, we went back to our initial goal to highlight the focal points of the solar controversy along the life cycle of solar panels. In the following large visualization we can observe the comparison of debates relating to each tag of our selection, after having filtered them according to a minimum count of 4. Each bubble represents a web page, its diameter represents the number of times that keyword appears within that specific page and its positioning along the vertical axe stands for the average positive or negative value assigned to the tag. Analysing this graphic let one discover the quantity of burning discussion over each single tag. A very heated controversy can have two main characteristics: very big bubbles located next to the zero on the vertical axe indicate that there is a strong debate over the positive or negative aspects relating to photovoltaic energy;

bubbles located next to the extremes of the axe instead indicate a clearly defined positioning of that web site according to that issue. In the end, another interesting feature of the visualization is the possibility to explore how the debated is handled among sites gotten through different Google fields, according to the colours of the bubbles. Thanks to this visualization we were able to isolate the most heated topics on which we focused in the following pages.

62 ch

BASIC WEB BLOGS DISCUSSIONS NEWS SCHOLAR

ss ec ea p t en ric er bil gy l b hi ills gh in co ce st nt iv in es du in st iti ry a in l co ve st st m e m nt ar ke ne t ed s pr ic sa e ta ving ca x c s rb re on di di ts ox id cl e im at cle a e ch n an g cl e ou dy ea em r t h en iss i v o gl iro ns ob n al me w ar nt m po i n g llu re tion cy re clin ne g w ab le w as w te ea th er el

in e

bu s

4. CONCLUSIONS

ECONOMICS ENVIRONMENT

1.0

SIZE: tag occurence within a single url

0.0

s f al ilic te on rn at ive fo coa ss l na il f tu ue ra l lg nu as c re lea so r ur ce s w at er w in d

SOLAR ENERGY

d ne t m lig et ht er in of g f pr gr od id uc ti st on or ag s e am up or ply ph ef ou fi m ci s ai en nt en cy an m ce at er i m al et po als t re ent si ial de nt ia l

gr i

co ba ns tte um ry co pti n o de ver n ve sio lo pm n en t e ge xce ne ss ra tio n

4. CONCLUSIONS

SOLAR PANELS ENERGY SOURCES

4. CONCLUSIONS

4.2 RING OF ADVANTAGES

FOCAL POINTS ALONG THE LIFE CYCLE OF PANELS Each one of the following visualizations maps the controversy over a single selected tag analyzed within the corpus of web pages. The representations are reserved just to the keywords that proved to be more controversial: unexpectedly these are not the most recurring ones in the debate, though. Reading these graphics permits to measure the burning quality of the focal issues and contemporarily to identify the type of web sites participating in the debate, that means also the speaking voices behind them. Thanks to the quotations in the lower part we tried also to give a sample of the terms these discussions were handled in. Starting from these preliminary mappings it is possible to begin specific researches about very single topic, deepening the analysis.

RING OF DISADVANTAGES SECTORS OF GOOGLE TOOLS PROVENIENCE

TAG

TOTAL COUNT OF TAGS USED TO HIGHLIGHT DISADVANTAGES

TOTAL COUNT OF TAGS USED TO HIGHLIGHT ADVANTAGES

0,0

Example of disadvantage found i n our c orpus o f URLs

1,0

Example o f a dvantage found i n our c orpus o f URLs

AVERAGE POSITIONING OF THE TAG

4. CONCLUSIONS

INITIAL COST

10 00-131 4-1

29-00

00 4-129-

00-131

TRADE & INSTALLATION

-1,0

0,0

ROOF

Initial costs are high so in practice installing a grid connected solar system is like paying your electricity bill up front, years in advance

Most certainly. For example, a system with solar panels facing on a -1,0 1,0 rooff in a westerly direction will generate far less than one with a northerly aspect

13 INITIAL COSTS 17

ROOF

0,0

Initial costs are not as prohibitive as they appear, because tax credits and rebates make solar systems more affordable

Equipment needs lots of room (unless the 1,0panels are on yourr rooff)

4. CONCLUSIONS

OPERATING LIFE

-1,0

MANTEINANCE

WIND

0,0

1,0

-1,0

0,0

1,0

4. CONCLUSIONS

-1,0

PRICE

GRID

0,0

1,0

-1,0

0,0

1,0

4. CONCLUSIONS

-1,

OFF-GRID

BATTERIES

0, 0

-1,

4. CONCLUSIONS

-1,0

FOSSIL FUELS

POLLUTION

0,0

1,0

-1,0

0,0

1,0

4. CONCLUSIONS

-1,0

LIGHT

EFFICIENCY

0,0

1,0

-1,0

0,0

1,0

4. CONCLUSIONS

RECYCLING

DISPOSAL / RECYCLING

-1,0

0,0

1,0

4. CONCLUSIONS

MARKET

ACROSS-THE- BOARD

-1,0

0,0

1,0