Solar Energy
= Despite its abundance and low environmental impacts, solar energy plays a relatively small role in our economy.
URL = http://commonsabundance.net/wiki/solar-energy/
This page discusses some of the barriers to its success, and provides links to initiatives to promote this energy use. Initial Version (February 3, 2013) by Courtney Cisler, student at Truman State University
Definitions
Solar energy is the light and heat energy radiating from the sun. Uses of this energy form include solar heating, photovoltaics, and appropriate architecture. Such uses can be divided into commercial purposes and residential design. They are divided into either passive or active solar technology based on whether they rely on basic heat absorption or technology and moving parts.
There are many benefits to solar energy – the most important being the fact that solar energy is renewable. It is environmentally friendly and, unlike conventional energy sources, releases no emissions into the air. Solar energy is cost-effective because the resource is abundant, and many forms of solar energy collectors last much longer than collectors of other energy sources. It can provide low-cost electricity in remote, off-grid areas almost anywhere in the world so that each family can generate its own power. Lastly, the use of solar energy could be a route to a country’s energy independence because the nation could end its reliance on foreign energy resources and potentially create a less volatile economy.
History
Solar energy has been used technologically since 700 BCE when it was discovered that the sun could be used to ignite materials through the use of magnifying glasses and mirrors. Specifically in buildings, solar energy was documented at least since 100 AD when it was observed that Romans built bath houses with large south-facing windows to warm the rooms. Similarly, cave dwellers in that time often chose caves facing the south with the purpose of capturing the sun’s heat in their homes.
In the late 1700s, Horace de Saussure invented the first solar collector for the purpose of heating water. Joseph Priestley and Lavoisier soon followed suit, establishing the foundation for solar technology as we know it today. The photovoltaic effect was discovered by Edmond Becquerel in 1839. Clarence Kemp popularized the use of solar energy with his invention of the solar water heater in 1891.
Modern solar technology took off in the 1950s with the invention of photovoltaic cells. Since then, solar panels have been adapted for a wide array of uses. Space exploration technology including Explorer III and Sputnik 3 were equipped with photovoltaic systems by the 1960s, and Volkswagen began experimenting with photovoltaic cells on its vehicles soon after. Completely solar-powered aircrafts have been piloted in several countries worldwide.
Photovoltaic cells also led to the construction of the first completely solar-powered home, built in the Hudson River Valley in 1983. Since then, researchers have been working to perfect the technology by improving its efficiency and making it more affordable. As new developments have been perfected for the global market, the production of photovoltaic technology has grown exponentially.[2]
Future
The goal of solar power is to enable individuals without access to standard energy sources to generate their own electricity on-site and independent of neighboring areas. Specifically in the United States, manufacturers aim to reduce costs by 75 percent within a decade to make the panels cost-competitive without subsidies.[3] The government’s goal is for solar energy to make up 10 percent of total energy production by 2025.[4]
It is estimated that within the next 10 years, the cost of photovoltaic power will decline to be comparable to that of traditional energy sources such as natural gas and coal powered electricity.[5] Net-zero energy buildings will become the norm as technology advances, so many homes will no longer rely upon currently standard energy forms. Improvements will likely take place in the basic design of solar collectors – including both efficiency and size, their efficiency under cloudy conditions, their potential for use from an architectural standpoint, and the ease of incorporating them into architectural designs. Advancements will reduce the costs of solar energy while simultaneously making it more popular in residential communities.
Goals for future expansion of the solar industry vary greatly by country. Germany is by far the global leader in the production of solar energy. The United States, South Africa, and Spain have also developed more advanced systems.[6] These industrially advanced countries tend to focus on developing new uses for the solar energy, as well as improved technology of photovoltaic cells. Less industrialized countries, however, aim to adopt the most basic solar technology on a small-scale level.
Discussion
Context within NORA
Needs
The provision of virtually all material needs involves the use of energy, and solar energy can help provide that. Plants capture solar energy directly in photosynthesis, but solar energy captured technologically can power the transport of all kinds of goods, as well as the heating and cooling of homes, and the manufacture of goods.
Resources
Energy
Solar energy is one type of energy resource. An increased use of solar energy can contribute to reducing our need for fossil fuels and thus reduce pollution and global warming.
Air
Use of solar energy can help to reduce air pollution from the combustion of solid or liquid fuels.
Water
Use of solar energy can potentially reduce water pollution from spilled liquid fuels (if less of those are needed). It can also potentially be used for sea water desalination, providing a renewable source of fresh water in arid areas close to coastlines.
Land
Solar collectors require substantial areas. However, this area can be minimized by placing solar collectors on rooftops.
Minerals
Photovoltaic panels require rare earth minerals, which are in short supply. Efforts to recycle these materials should be greatly increased.
Understanding Current Patterns of Abundance and Scarcity
The US Department of Energy calculates that the entire world could be powered by a photovoltaic array of 496,805 square kilometers – an area approximately equal to five percent of the Sahara Desert. If solar farms were constructed at a rate equivalent to the land area deforested each year, it would take only three years to power the globe with solar energy.[7] Why, then, do we not already have an abundance of solar power?
Favoritism Toward Conventional Energy
The use of this renewable resource has been so widely opposed that supplying the world with solar power is considered an unrealistic goal. Most utilities have shown that they are unwilling to promote the use of alternative forms of energy unless all conventional forms have been exhausted. Over the past several years, the rate of solar panel installations has been doubling each year, but this is still relatively slow growth. Currently, 85 percent of the world’s commercial energy is still derived from oil, natural gas, and coal.[8]
Much of this opposition is caused by a general lack of understanding about the technology. Conventional energy is less expensive, and the industries are trusted by the people. Many believe that renewable energy will have negative economic and environmental impacts on their community, as well as compromise their safety and energy security. In reality the expansion of renewable energy usage has often been proven to create jobs and stimulate the economy, and it is much cleaner than conventional energy.[9]
Lagging Technology
A major obstacle which prevents widespread use of solar energy is the lack of technological advancements in the field. Researchers are constantly working toward developing an improved model of photovoltaic cells, as well as investigating new ways to harvest the sun’s power.
This energy can be difficult to store in an efficient and cost-effective way, which makes solar power much less realistic to use. The most popular storage method currently involves banks of batteries, which must be very large, and are therefore expensive and unrealistic in community-sized proportions. Using the energy to pump water with the intention of converting it to hydropower is also an accepted method of storage and is widely used, though not as practical for small communities or use for off-grid systems. Storage technology could greatly benefit from advancements in superconducting magnets and improved capacitors. Modern scientists often look to the photosynthesis mechanisms in plants for inspiration. Researchers have found methods to use the sun's energy to split water's oxygen and hydrogen molecules which can be stored and later combined in a fuel cell to produce electricity. While this works well in plants and small experiments, it will require much more research to be feasible for powering an entire building.[10]
The most common solar cells today only convert between ten and twenty percent of the energy received into usable electricity.[10] This means that the cost of energy derived from solar sources is much higher than necessary. Engineers must find a way to make the cells more efficient. The most commonly used material, silicon, allows a maximum efficiency of 31 percent; cells could theoretically exceed this if an alternative element was used. Current research geared toward multilayer cells and nanotechnology may offer a solution to this issue, and have been predicted to reach efficiencies as high as 80 percent.[10]
Obstacle of Cost
It is often difficult to persuade people that the use of photovoltaic cells is cost effective, although it very much is. Installation of solar panels requires a high initial investment. However, the system will usually pay for itself within the first few years, and will afterward save its users money compared to using fossil fuels. Furthermore, costs have been steadily declining.
The cost of photovoltaics varies greatly with the country in which they are produced. For the last few years, China is by far the leading manufacturer in this field.[11] Manufacturing costs depend on the resources used to build the system, as well as their abundance. Alternative materials may therefore be highly beneficial for this issue. Companies must develop technology which is thin enough to carry electrical charges a short distance, therefore reducing the requirement for the material to be pure, and thus reducing the cost. However, the material must also be thick enough to absorb much sunlight.
Limitations of Resource
One main issue with the use of solar energy is its uneven distribution across the world. Although solar energy is abundant in deserts and arid zones, the regions in the world where the most energy is consumed face shortages in solar energy. The sun’s power received by the Earth provides approximately 10,000 times the current commercial energy consumption on the planet, but it is too unevenly distributed to be realistic with current technology and modes of usage.[12] Despite the fact that this resource is completely renewable, has no cost, and is available to everyone, it is an unreliable resource for most of the population unless combined with other renewable energy sources such as wind power, in which case it becomes a valuable source of power.
Timing also contributes to the abundance or lack of solar energy for widespread use. Regions with harsh winter conditions may face difficulties in acquiring enough solar energy to fulfill their needs. Thus, solar energy can be considered a limited resource. A major concern in the use of solar energy is the lack of reliability of the resource. Studies show that half of the solar energy in in mid-latitude cities of the northern hemisphere is collected between May and August.[13] While solar technology is a valuable resource during these months, it cannot be considered abundant enough for widespread usage during other seasons. Without further technological advancements, it is not feasible to use solar energy as a main resource year round. It is crucial that researchers develop an efficient method of storing the electricity collected during sunny hours. While solar energy can effectively be coupled with other renewable resources, such as wind energy which is often more abundant when solar energy is lacking, to supply communities with energy, it cannot be depended upon as a sole source for powering a neighborhood.
Lastly, other technological advancements limit the availability of solar energy. Pollution limits the availability of solar radiation in that it blocks sunlight and reduces the intensity of the sun’s rays. In particular, this negatively impacts industrialized regions where pollution has more profound effects. For every global temperature increase of 2° Celsius, the efficiency of photovoltaic cells decreases 1 percent. With the current size of the photovoltaic industry, this would result in $1 billion of energy lost annually.[14]
Graphic showing variation of solar insolation by latitude and season
More on solar energy reaching the earth's surface
Opposition to Solar Energy
Widespread use of solar energy would benefit a nation in many ways, as it would both be healthy for the environment and would improve the economy by making the country energy independent. However, multiple institutions would face losses if solar energy were generally available. Since solar energy is typically advertised in conjunction with information regarding impending fuel shortages and increased costs of traditional fuel sources, it is clear that such industries would fall apart if solar energy were to be used more commonly.
Oil companies are the primary opponents of solar energy. Recently, in the 2012 United States presidential election, coal, oil, and natural gas manufacturers spent $153 million to promote the industry and criticize renewable energy.[15] Their revenues rely strictly on the idea that oil and natural gas are the primary feasible forms of energy, and that these are vital to human populations regardless of their environmental impacts. As long as we depend primarily on fossil fuels, the oil industry has complete control over prices and may raise them whenever there are shortages. Thus, the implementation of solar radiation as the most common form of energy would be a major setback for the oil industry. Nations whose main export is oil would suffer an economic downturn in this case.[16]
Similarly, the construction of net-zero housing would be a major setback for all fossil fuel industries, as well as all electric companies. Institutions which could not convert to solar energy quickly enough or efficiently reduce costs would not maintain their power through such an energy shift. They therefore band together to oppose advancements in solar energy technology. In the state of New York, six electric companies joined forces to combat a recently proposed energy bill. Similarly, interest groups work closely with the government to stop the passing of legislation for stricter environmental regulations. They also attempt to inhibit funding for research for alternative energy sources.
Lastly, the implementation of widespread solar energy may create conflicts over land use. Widespread use of solar energy requires large surfaces exposed to the sun. Some locations, such as remote deserts, may be more favorable locations for solar technology. Unfortunately, these locations are often controlled by entities which do not support solar initiatives, and require transmission of electric power across large distances. Land availability can also be an issue on a smaller scale. Communities may favor more dense developments, which tend to block sunlight. While this problem can be addressed through the use of rooftops as solar collectors, some communities may protect trees, which also prevent sunlight from reaching its target.[17] Some creative use of presently underutilized spaces may be needed, as for example covering parking lots with photovoltaic collectors which could even protect the areas beneath from sun and rain.
Approaches toward greater abundance
Technologies
Active
- Photovoltaics (large scale)
- Photovoltaics (small scale; rooftop)
- Solar Thermal (large scale)
- Solar Thermal (small scale)
- Energy Storage
- Smart grids
Passive
Economic and Social
- Government incentives and subsidies
- Solar cooperatives
- Solar commons
- Solar energy financing (example)
The Future of Solar Pricing
Vinay Gupta:
" let me give you an example of something that’s changing in a semi-predictable way right now, which is the price of solar panels. Solar panels have fallen in price by 7% a year, every year for the past 40 years. So, on the order of every decade, the price of solar panels halves. 30 years out you can rationally expect the price of solar panels to be less than a 10th of what it is now, and as a result the entire global energy landscape will change.
Energy relates to every single economic process we have. It gets deep inside of the structure of things like bitcoin because of the ratio of costs. It is an absolutely ubiquitous part of human life. So, when you hear people talking about 10-15-20-30 year projections forward and they don’t talk about the exponential fall in energy prices, they’re living in a fantasy land. There’s just no such place.
Let me show you a thing. This yellow cable that I have around my keys is a material called “spectra” [dyneema]. Everybody see that? So, spectra is a nanomaterial. The breaking strength of that piece of string is in excess of 400 kg. And sometimes I demonstrate this by having people pull on it in teams, 4-5 people on each side. This stuff will cut into wood half an inch. It’s 40p a meter on Amazon. It’s just dirt cheap; long chains of carbon atoms axially aligned with the forces. [on the cable]
So you look out 30 years this stuff is going to be everywhere. They’re spinning it into clothes. Levi’s is making jeans that are laced through with spectra today; you can buy them for about £80 a pair. Look forward 10 years, the ubiquotous use of clothing, construction. Look forward 20 years, solar substantially cheaper than any other kind of power available. Look forward 30 years, nanotechnology, biotechnology, replicator engineering are everyday parts of life." (http://vinay.howtolivewiki.com/blog/other/my-bitcoin-expo-london-talk-nov-2013-with-transcript-3539)
More Information
Resources for Further Information
For a brief outline of the many uses of solar energy, check out http://www.solarenergy.com.
To learn about even more applications of solar energy, with more than 1000 pages of diagrams, data, and explanations, check out the book Solar Collectors, Energy Storage, and Materials by Francis de Winter (1990).
For current information outlining solar and other forms of renewable energy, consult this recent report compiled by REN21.
For recent news in the solar community, visit the US Department of Energy solar energy website.
To connect with others interested in solar energy, explore the American Solar Energy Society's website.
To find out more about the solar energy movement, read the book A Solar Manifesto by Hermann Scheer (2005).
References
[1]http://www.renewableenergyworld.com/rea/tech/home
[2]http://www1.eere.energy.gov/solar/pdfs/solar_timeline.pdf
[3]http://www1.eere.energy.gov/solar/pdfs/52018.pdf
[4]http://www.greenamerica.org/programs/climate/cleanenergy/usastudy1.cfm
[5]http://www.ieee.org/about/news/2011/15june_2011.html
[6]http://education.nationalgeographic.com/education/media/solar-energy-graphics/?ar_a=1
[7]http://landartgenerator.org/blagi/archives/127
[8]http://www.energy4me.org/energy-facts/energy-sustainability/
[9]http://www.irena.org/DocumentDownloads/Publications/Renewable_Energy_Jobs_and_Access.pdf
[10]http://www.mesg.nl/wiki/images/f/fd/Paper_VGTU_03.pdf
[11]http://www.export.gov.il/uploadfiles/03_2012/chinisrenewableenergyindustry.pdf
[12]Cunningham, William P., and Mary Ann Cunningham. Environmental Science: A Global Concern. 11th ed. New York: McGraw-Hill Higher Education, 2010. Print.
[13]http://www.eecis.udel.edu/~honsberg/Eleg620/02_Solar_radiation.pdf
[14]apollo.eas.gatech.edu/EAS6410/2004/term_papers/hanley.ppt
[16]http://blueocean.org/issues/opposition-to-clean-energy/
[17]http://www.planning.org/pas/infopackets/open/pdf/30part1.pdf
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