The sun provides a virtually unlimited, clean, and free fuel at a price that never changes. Solar farms take advantage of that resource, with large-scale arrays of hundreds, thousands, or in some cases millions of photovoltaic (PV) panels. They operate at a utility scale like conventional power plants in the amount of electricity they produce, but dramatically differ in their emissions.
Solar farms can be found in deserts, on military bases, atop closed landfills, and even floating on reservoirs, deploying silicon panels to harvest the photons streaming to earth. Inside a panel’s hermetically sealed environment, photons energize electrons and create electrical current—from light to voltage, precisely as the name suggests.
Bell Labs debuted silicon PV technology in 1954. At that time, photovoltaics cost more than $1,900 per watt in today’s currency. Since then, public investment, tax incentives, technology evolution, and brute manufacturing force have chipped away at the cost of creating PV, bringing it down to sixty-five cents per watt today.
In many parts of the world, solar PV is now cost competitive with or less costly than conventional power generation. In tandem with other renewables and enabled by better grids and energy storage, solar farms are ushering in the clean energy revolution.
life cycle emissions [vs.] coal plants: Schlömer, S., et al. “Annex III: Technology-Specific Cost and Performance Parameters.” In Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK, and New York: Cambridge University Press, 2014.
outdoor air pollution…premature deaths: WHO. Burden of Disease from Ambient Air Pollution for 2012. Geneva: World Health Organization, 2014.
utility-scale…additions to solar PV capacity: IRENA. Letting in the Light: How Solar PV Will Revolutionize the Electricity System. Abu Dhabi: International Renewable Energy Agency, 2016.
[proposed] Chernobyl…solar farm: Vidal, John. “Chernobyl Could Be Reinvented as a Solar Farm, Says Ukraine.” The Guardian. July 29, 2016.
Bell Labs…“solar battery”: Perlin, John. Let It Shine: The 6,000-Year Story of Solar Energy. Novato, California: New World Library, 2013.
“the beginning of a new era”: “Vast Power of Sun is Tapped by Battery Using Sand Ingredient.” New York Times. April 26, 1954.
At that time…$1,900 per watt: Mathiesen, Karl. “What is Holding Back the Growth of Solar Power?” The Guardian. January 31, 2016.
use [by] the oil industry: Perlin, Shine.
sixty-five cents per watt today: Weiser, Matt. “Here Comes the Sun: US Solar Power Market Hits All-Time High.” The Guardian. June 28, 2016.
cost competitive with…conventional power: IRENA, Solar PV.
bid[s]…at pennies per kilowatt-hour: Dipaola, Anthony. “Cheapest Solar on Record Offered as Abu Dhabi Expands Renewables.” Bloomberg. September 19, 2016.
panels rotate…generation can improve: Greentech Media. “Solar Balance-of-System: To Track or Not to Track, Part I.” November 28, 2012.
annual carbon dioxide savings [from PV]: IRENA, Solar PV.
20 percent of global energy needs by 2027: Farmer, J. Doyne, and François Lafond. “How Predictable is Technological Progress?” Research Policy, 45 (2015): 647–665.
solar PV…in Italy…Germany and Greece: REN 21. Renewables 2016 Global Status Report. Paris: REN21 Secretariat, 2016.