Solar Energy: A Bountiful Harvest

Solar energy has a lot going for it: it’s the fastest growing energy sector in the world — last year, it even grew faster than fossil fuels[1] — and analysts predict it will soon become the cheapest[2].

 

The sun’s energy is not only clean compared to fossil fuels — coal produces 94% more greenhouse gases and other pollutants[3] — but also far more plentiful: just two hours of sunshine contains more energy than humans consume in a year[4].

 

When we think of solar, rooftop panels on homes and businesses usually spring to mind. However, most solar energy actually comes from utility-scale installations comprised of hundreds to millions of panels. They are aptly called solar farms because they “are literally a means of energy harvesting”[5].

How Solar Farms Work — and Where

 

There are two main types of solar technology: photovoltaic (PV) and concentrated solar power (CSP). PV panels use photon energy (light), whereas CSP panels use thermal energy (heat) to generate electricity.[6] The sticking point is price: CSP is far more expensive to produce, so PV comprises 97% of existing global — and over 90% of U.S. — solar energy.[7]

 

China is currently the runaway industry leader; not only does it produce over 60% of the world’s solar panels, but it also has more capacity — 130 gigawatts — than any other country; in fact, China produces enough solar power to run the UK many times over[8]. A full quarter of the world’s solar PV farms are in China, while Japan, Germany, and the U.S. lead the rest of the world[9] with about 13% of the global output each.

The Future of Solar Farms: Rays of Sunshine with a Few Dark Clouds

 

Unlike other types of power, solar farms can be built in only a few months, one of many reasons it now can cost as little as $0.65 per watt[10] on average, with some prices falling as low as $0.04 per kilowatt hour[11].

 

Solar PV farms have their drawbacks, however. Sunshine only reaches panels during the daytime and under relatively sunny conditions, so other types of power  — usually fossil fuels — must pick up the slack during peak nighttime and cloudy hours.

At the same time, too much solar power has resulted in California utility companies not only selling off their solar power but even paying other states like Arizona[12] to take these energy reserves off their hands in order to prevent their grids from overloading.

 

Solutions for both over- and under-production are potentially on the horizon, however, beginning with supergrids connecting countries; Europe leads the way, with a goal of 10% interconnection capacity across borders by 2020[13]. A orbital solar power system in space[14] has even been proposed by Japan to replace its reliance on nuclear energy.

The biggest concern with solar farms, however, is one of sustainability: solar panels have a lifespan of only about 30 years, and 10% of their materials are toxic pollutants[15], from sulfuric acid to lead and chromium.

 

Currently, it is cheaper to make new solar panels than to recycle. Analysts predict, however, that solar recycling could be nearly a $400 million industry by 2024[16], and the first European recycling plant[17] opened in 2018 with contracts to recycle almost all of France’s outdated solar panels. Ideally, this potential sustainability problem can be transformed into an economic and environmental opportunity.

 

As the members of the Drawdown coalition put it: “solar power is a solution, but it might be fair to say it is a revolution as well.”[18] And solar farms are leading the way.

[1] https://www.openaccessgovernment.org/solar-energy-farms/56768/

[2] https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2018/Jan/IRENA_2017_Power_Costs_2018_summary.pdf?la=en&hash=6A74B8D3F7931DEF00AB88BD3B339CAE180D11C3

[3] Drawdown, 8.

[4] https://www.nbcnews.com/mach/science/supersized-solar-farms-are-sprouting-around-world-maybe-space-too-ncna901666

[5] Drawdown, 8.

[6] https://medium.com/cleantech-rising/a-beginners-guide-to-concentrated-solar-power-csp-d5e6f9d12cdc

[7] http://energy.mit.edu/wp-content/uploads/2015/05/MITEI-The-Future-of-Solar-Energy.pdf

[8] www.bbc.com/future/story/20180822-why-china-is-transforming-the-worlds-solar-energy

[9] http://www.iea-pvps.org/fileadmin/dam/public/report/statistics/IEA-PVPS_-_A_Snapshot_of_Global_PV_-_1992-2016__1_.pdf

[10] Drawdown, 8.

[11] http://fortune.com/2016/06/13/solar-to-get-crazy-cheap/

[12] https://www.latimes.com/projects/la-fi-electricity-solar/

[13] https://www.ge.com/reports/helping-europe-interconnected-supergrid-right-way-digital/

[14] http://www.kenkai.jaxa.jp/eng/research/ssps/hmi-index.html

[15] www.sixthtone.com/news/1002631/the-dark-side-of-chinas-solar-boom-

[16] www.sixthtone.com/news/1002631/the-dark-side-of-chinas-solar-boom-

[17] https://www.reuters.com/article/us-solar-recycling/europes-first-solar-panel-recycling-plant-opens-in-france-idUSKBN1JL28Z

[18] Drawdown, 9.

 

Related LEED® v4 Credits:

  • LEED BD+C, EAc Renewable Energy Production  (1-3 pts)
  • LEED BD+C, EAc Green Power and Carbon Offsets  (1-2 pts