Though the US International Trade Commission (ITC) approved an investigation into charges of unfair Chinese trade practices in the solar energy sector on Dec 2, industry experts said that rather than confronting each other, China and the US should cooperate based on their respective advantages in solar power. \"Chinese and US solar companies can cooperate on research and development (R&D) to further improve conversion efficiency, the economics of photovoltaic technologies and joint manufacturing activities to lower the unit cost of solar panels,\" said Kevin Tu, senior associate of China energy and climate policy at the Carnegie Endowment for International Peace. \"Chinese solar companies lead the world in the downstream portion of the photovoltaic value chain, especially solar panel manufacturing,\" Tu added. The ITC took the first step toward imposing added tariffs on Chinese solar imports, voting unanimously on a petition by Bonn-based SolarWorld AG that called for anti-dumping and countervailing duties. The commission will now hold a full investigation. China rejected the preliminary ruling that imports of Chinese solar panels are harming the domestic industry, saying the decision shows the US \"inclination to trade protectionism\". GCL Solar Energy Inc, China\'s leading polysilicon and wafer maker, which has been investing in solar projects in the US, said the US solar companies have advantages in technological innovation but some of them are far from commercial. The Chinese solar power investor, which has about 400 megawatts of projects in the pipeline in the US market, said it sourced panels from international suppliers in China, the US and Japan.