By Jarrett Renshaw and Nichola Groom (Reuters) -U.S. President Joe Biden extended Trump-era tariffs on imported solar energy equipment by four years on Friday, but in a major concession to installers he also eased the terms to exclude a panel technology dominant among big U.S. projects. The decision represented a balancing act by the Biden administration to meet the demands of two important political constituencies: union labor which supports import restrictions to protect domestic jobs, and clean energy developers keen to access cheap overseas supplies. The four-year extension of the tariff e…