According to Lester Brown of the Earth Policy Institute, harnessing of solar energy is expanding on every front as concerns about climate change and energy security escalate, as government incentives for harnessing solar energy expand, and as these costs decline while those of fossil fuels rise.

Brown said one solar technology that is really beginning to take off is the use of solar thermal collectors to convert sunlight into heat that can be used to warm both water and space.

Using China as an example, Brown said it’s now home to 27 million rooftop solar water heaters.

“With nearly 4,000 Chinese companies manufacturing these devices, this relatively simple low-cost technology has leapfrogged into villages that do not yet have electricity,” Brown said.  ”For as little as $200, villagers can have a rooftop solar collector installed and take their first hot shower.”

He said the technology is sweeping China like wildfire, already approaching market saturation in some communities. Beijing plans to boost the current 114 million square meters of rooftop solar collectors for heating water to 300 million by 2020.

Brown said the energy harnessed by these installations in China is equal to the electricity generated by 49 coal-fired power plants.

“Other developing countries such as India and Brazil may also soon see millions of households turning to this inexpensive water heating technology.” he said. ”This leapfrogging into rural areas without an electricity grid is similar to the way cell phones bypassed the traditional fixed-line grid, providing services to millions of people who would still be on waiting lists if they had relied on traditional phone lines. Once the initial installment cost of rooftop solar water heaters is paid, the hot water is essentially free.”