|Rows of solar collectors line the roofs of many buildings in China.|
Driving through Jiangsu and Anhui provinces adjacent to Shanghai, China, last month, I was struck. Not by the sheer number of people and vehicles, or by the seemingly endless number of new buildings under construction with their distinct bamboo scaffolding, but by what was on top of those roofs: continuous rows of solar collectors.
China’s increasing emphasis on renewable energy on a large-scale level can be seen by wind farms  in Inner Mongolia and several other green World Bank projects  in the country. However, the most pervasive example for the public and individuals has been the explosion of the use of solar water heaters.
Due to a combination of research and development, market competition, and government incentives in China, models designed for families of three start at around 1500 Yuan or US$200 – about 70-80 percent less than the least expensive models in the United States. (High-end models have higher capacities and are able to seamlessly switch between solar and gas power.) Chinese companies also are apparently helping push down the price of solar panels – by almost half over the last year – in other countries, according to a recent New York Times article .
I recently talked to Erik Desrosiers of Opsun Technologies , who told me that China produces more than 60 percent of the world’s solar cells and other high quality products at a low cost. He said that most water heaters in China are solar thermal heaters, which use evacuated tube  technology. Desrosiers also said it’s more prevalent in China due to need, density, and less stringent building codes.
The market has been rapidly expanding. To put it into perspective, there are an estimated 600,000 workers solely employed in installing solar water heaters – which is about the population of Washington, DC.
In Shanghai, a resident of the Moon River community Wang Lijun told me, “I installed a solar water heater in my home because it brings my family many benefits. I feel that it’s safer, has less impact on the environment, and saves me money in electric and gas bills.”