china solar energy is general in our country.it has a long history,the history of
solar energy can dates back to 1958.Tianjin University has 12.6 square meters of solar bathroom. By 1973 the world energy crisis, the search for renewable energy, China in the late 70s of last century, increased research and development and production of
solar collectors. Some units before and after 1979, head of R & D all-glass
vacuum tube collector. Tsinghua University, the physical background of the use of power vacuum, stuck with it. Cattle is an elongated structure, but there is a layer including glass selectively absorbing coating.