The US has filed a trade complaint against China over its support for its wind-energy manufacturers, at the World Trade Organization in Geneva.

The case is the first filed by the US on green technology, following complaints about Chinese efforts to force manufacturers to make those products in the country, according to Bloomberg.

A Chinese Government fund, China’s Special Fund for Wind Power Manufacturing, requires recipients to use Chinese-made parts and amounts to a subsidy, both of which violate WTO rules, according to the US Trade Representative’s office.

The Chinese aid could total several hundred million dollars, according to the US.

American Wind Energy Association (AWEA) senior vice president Rob Gramlich told Bloomberg that their role as a global exporter of wind turbines relies on a level playing field in international markets.

China is now the largest wind-power market in the world in terms of installed capacity, and is growing at 116% a year, compared with 40% in the US.