From magnifying glasses to steam engines, scientists through the centuries have found innovative ways to harness the power of the sun. Converting more solar power into electricity is high on the political agenda in many countries, amid the push to find domestic energy sources that are less polluting than fossil fuels.
Distribution
Despite rapid growth in recent years, solar power accounts for less than 1 percent of United States electricity use. Solar power is more entrenched in European countries such as Spain and Germany, which have promoted its development with strong incentives called feed-in tariffs,which require electric utilities to buy solar power at a high, fixed price. In the United States, California is by far the leading solar state.
How it Works
There are several ways to use the sun’s power to generate electricity. One of the most promising is called concentrating solar power. This involves using mirrors to reflect and focus the sun’s rays, providing heat, which in turn helps power a generator. Another is photovoltaic panels, such as the displays on the rooftops of homes and office buildings (some of these displays, especially in California, have recently experienced problems with theft).
Drawbacks and Incentives
The drawback to solar power is that it is expensive to produce: generating power from photovoltaic panels costs more than four times as much as coal, and more than twice what wind power costs. In the United States, the federal government and states have offered a variety of incentives to encourage homeowners and businesses to put panels on their roofs, and for utilities to buy power from large displays. Solar panels produce no energy at night, but that is not a significant problem because the electricity is often most needed in the daytime, when consumers turn on lights and televisions and air-conditioning.
Solar energy is also used to heat water and pools — and of course a properly designed house will optimize the light and heat qualities of as it floods through the windows.
For now, electricity generation from the sun’s rays needs to be subsidized because it requires the purchase of new equipment and investment in evolving technologies. But costs are rapidly dropping. And regulators are still learning how to structure stimulus payments so that they yield a stable green industry that supports itself.
China Leading Solar Race
China has leapfrogged the West to emerge as the world’s largest manufacturer of solar panels. China’s efforts to dominate renewable energy technologies raise the prospect that the West may someday trade its dependence on oil from the Mideast for a reliance on solar panels, wind turbines and other gear manufactured in China.
The Chinese government charges a renewable energy fee to all electricity users. The fee revenue goes to companies that operate the electricity grid, to make up the cost difference between renewable energy and coal-fired power.
In the United States, power companies frequently face a choice between buying renewable energy equipment or continuing to operate fossil-fuel-fired power plants that have already been built and paid for. In China, power companies have to buy lots of new equipment anyway, and alternative energy is increasingly priced competitively.
But China’s commitment to renewable energy is expensive. Although costs are falling steeply through mass production, solar power is still at least twice as expensive as coal.