Will Clean Energy Ever Be a Reality in the U.S.? Here's What's Standing in Our Way

Renewable energy is essential if we are to avert disastrous climate change caused by carbon-dioxide emissions from burning fossil fuels. Yet despite significant recent growth, less than 2 percent of the about 4 trillion kilowatt-hours of electricity the U.S. generates a year comes from solar or wind power. More than two-thirds still comes from coal, natural gas or oil, and 20 percent from nuclear power. Meanwhile, the world's total reserves of oil, gas, coal, and uranium are expected to run out by the end of the century, especially as electricity consumption increases.

So what are the obstacles to converting the U.S. electrical system to renewable energy? They are a mix of technological, economic and political factors.

Solar and Wind Make Gains

Solar energy has become "economically viable only in recent years," says Seth Masia, deputy editor at Solar Today, an industry trade magazine in Boulder, Colorado. Prices for photovoltaic panels--the most commonly used devices to convert sunlight to electricity--have dropped dramatically, Masia notes, as "Chinese manufacturers have flooded the market with low-cost devices."

Germany is the world leader in switching over. Early this year, the amount of its electricity that came from renewables passed 20 percent. Solar output almost doubled from the previous year; a utility trade group credited plummeting costs for solar panels and the government deciding to retain subsidies for private solar-power generation. Wind and solar sources now make up almost half of all new electricity generation in Europe, says Ken Zweibel of the GW Solar Institute at George Washington University.

In the U.S. overall, renewables have become a significant percentage of new electricity generation, although this amount fluctuates with the market. In April, California Gov. Jerry Brown signed a law requiring 33 percent of all electricity produced by utilities in the state to come from renewables by the end of 2020. Masia projects that 20 percent of U.S. electricity could come from solar power by then.

Contracts have been signed for solar-power plants with a capacity of 13 gigawatts--enough to power New York City at the record-high peak set during last July's heat wave--to come online by 2016, says Brett Prior, a senior analyst with Greentech Media in Boston. That means solar power could be 20 percent of new capacity by then, he adds.

Some plants use large arrays of photovoltaic panels. Others employ more complicated systems to concentrate solar power, such as parabolic trough mirrors that heat an oil-filled tube to 1,000°F and generate steam to spin a turbine. Most are in California and Arizona, but there are others underway in Colorado, Nevada, the Long Island suburbs of New York City, and Austin, Texas. Construction has begun on three 250-to 370-megawatt plants in Southern California deserts, but two larger ones--a 1-gigawatt plant at Blythe and a 709-megawatt one in the Imperial Valley--have been delayed for further state review, because they switched their plans from concentrated solar power to photovoltaic cells.

Texas now gets 8 percent of its electricity from wind. This is largely due to a 2005 state law that established collaboration between wind-farm developers and utilities, says Mark Kapner, a retired senior engineer in Austin Energy's renewables division. If wind developers commit to building on a site, the utilities will commit to building power lines out to it, and the cost of transmission will not increase with distance.

This is important, Kapner explains, because the strongest winds are in remote areas, such as west Texas and the rest of the Great Plains. Before the bill was passed, wind turbines had to be taken out of service sometimes, because they were generating more electricity than the existing power lines could handle.