When one side of the earth is lit by the sun, the other side is in dark. This highlights the importance of joint efforts in developing solar energy.

But worldwide efforts have often met challenges, as in the latest anti-dumping and anti-subsidy investigations launched by the United States against China's photovoltaic (PV) products.

China's PV industry issued a statement on Wednesday, opposing the second investigation in three years by the United States, several days ahead of the release of the US preliminary investigation results.

The United States initiated the investigations in February, the second after a similar one in 2011, which slowed the Chinese PV industry and damaged the development of the US PV application market.

This time, the preliminary anti-subsidy investigation result is expected on June 2 and the preliminary anti-dumping investigation findings on July 28.

A large amount of hard evidence presented by the Chinese companies during the last investigation has already proved that there are no such things as dumping or illegal subsidies.

Chinese PV products win the affection of the world based on superior quality, reasonable prices and good after sales services, rather than taking advantage of any government subsidies.

It is a great pity the evidence was ignored by the US side.

The protectionism measures of the US side will not only hurt Chinese exporters, but also domestic market players and American people due to higher prices they would have to pay.