WUXI, China  President Obama wants to make the United States “the world’s leading exporter of renewable energy,” but in his seven months in office, it is China that has stepped on the gas in an effort to become the dominant player in green energy  especially in solar power, and even in the United States.

Chinese companies have already played a leading role in pushing down the price of solar panels by almost half over the last year. Shi Zhengrong, the chief executive and founder of China’s biggest solar panel manufacturer, Suntech Power Holdings, said in an interview here that Suntech, to build market share, is selling solar panels on the American market for less than the cost of the materials, assembly and shipping.

Backed by lavish government support, the Chinese are preparing to build plants to assemble their products in the United States to bypass protectionist legislation. As Japanese automakers did decades ago, Chinese solar companies are encouraging their United States executives to join industry trade groups to tamp down anti-Chinese sentiment before it takes root.

The Obama administration is determined to help the American industry. The energy and Treasury departments announced this month that they would give $2.3 billion in tax credits to clean energy equipment manufacturers. But even in the solar industry, many worry that Western companies may have fragile prospects when competing with Chinese companies that have cheap loans, electricity and labor, paying recent college graduates in engineering $7,000 a year.