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Eugene Weekly : Viewpoint : 12.3.09




Facing the Facts

Photovoltaic panels are a net loss for the environment 

By Warren Weisman

In 1979, President Carter placed solar panels on the White House roof and predicted 20 percent of America’s energy would be provided by solar power by the year 2000. Today solar power provides less than one 10th of 1 percent of the nation’s energy. Solar proponents blame this shortfall on opposition from fossil fuel lobbies or a lack of political will to go solar. In reality, the reasons have nothing to do with politics and everything to do with basic physics. 

To understand solar panels it is important to understand that photovoltaic panels do not create energy; they convert a small amount of the sun’s energy that hits them into electric current. The average amount of sunlight that falls on a square meter of the earth is about 200 watts an hour. Obviously, most of it during a few hours during midday. Tucson, Arizona gets 250 watts, London, England gets 100. How much of that energy can a solar panel capture?

 Today’s solar panels are about 15 percent efficient. Meaning, with a one square meter solar panel we could harvest 38 watts in Tucson, and 15 in London, or 900 and 360 watts over a 24 hour period, respectively. Future solar panels may increase efficiency — though 100 percent efficiency is not possible — but they will always be limited by the amount of energy in a given square meter of sunlight.

The response to this limitation is real estate. A typical household installation might include 20 square meters of solar panels. But if 20 meters of solar panels were placed on the roof of every one of the 128 million homes in America, it would provide less than 2 percent of the 101 quadrillion BTUs of energy consumed in the U.S. each year.

Low voltage current from solar panels is sufficient for lighting, charging cell phones or turning on a laptop computer, but not sufficient to drive electric motors, pumps or heating elements. Solar panel systems cannot heat your home, pump water, run power tools, washer or dryer, iron, sewing machine, hair dryer, refrigerator, garbage disposal, chest freezer, hot water heater, desktop computer, toaster, blender or food processor. In short, solar power cannot do the work we most need electricity to do, and doesn’t do so when we need it the least. 

Covering the American Southwest with solar panels makes sense to many who are under the impression solar panels produce no greenhouse gas emissions or pollution. This is not the case. The amount of carbon emissions in the solar panel manufacturing process per kilowatt-hour of electricity varies from 25 grams of CO2 for thin film solar cells to 55 grams of CO2 per kilowatt-hour for silicon-based cells. For a typical home installation, this could vary between 3,140 kilograms of CO2 in sunny places and 6,280 kilograms of CO2 in less sunny regions — a carbon equivalent of between 350 and 700 gallons of gasoline for every household. While still one-quarter of the CO2 emissions of fossil fuels, solar panels are far from zero emissions.

Furthermore, as more firms switch to thin film solar cells, the use of nitrogen trifluoride is increasing — a greenhouse gas with 17,000 times the global warming potential of CO2 and an atmospheric lifespan of 740 years. Before the Earth’s atmosphere enjoyed a modest reduction in greenhouse gases from solar panel use, it would first endure a massive release of greenhouse gases from the manufacturing process.

An even harder area for solar panels to call themselves green is in the area of toxic wastes produced during their manufacture. In March 2008, The Washington Post reported on Chinese solar panel firms dumping silicon tetrachloride in rural villages — a hazardous byproduct from the production of polysilicon solar cells. Eerily reminiscent of the toxic e-waste that resulted in deaths, illnesses and birth defects in Silicon Valley in California during the dawn of the Information Age. Solar cells made in China are sold to manufacturers around the world, including the U.S. 

Solar panels last only 20 to 30 years and then are not recyclable. Mountains of old solar panels are expected to begin showing up in American landfills by 2020. 

Solar panels are bound by inescapable laws of physics to never produce more than a token amount of the nation’s energy. They are toys for affluent homeowners and businesses to show how green — or gullible — they really are; and to have taxpayers help pay their utility bills through net metering. Solar panels are most certainly not carbon neutral and involve a host of negative environmental impacts. Most importantly, they are a distraction from conservation efforts and from research into realistic alternatives to fossil fuels for energy independence and climate change mitigation. As long as the solar power myth continues, the future remains bright for coal-fired power plants.

Warren Weisman is project director of Complejo de Energía Renovable, México (CEREM), a non-profit biogas power plant, education and training facility planned in Puerto Vallarta, Mexico.