How long has this type of collector been in existance?
Pepole have been warming themselves with ths sun for many years. Following the energy crisis in the 1970s there was increased interest in using this energy to heat water. Evacuated tubes were created in the 1980s and, like many innovative products developed during that decade, they were very successful but came with a very high price tag. The evacuated tube system was further improved in the early 1990s by Dr Yukun Pei. He took a number of advancements that were made in his work at the famous Massachusetts Institute of Technology (MIT) back to his native China. It was here that he shared the technology with a number of Chinese manufacturers, and the glass twin walled evacuated tube water heating system was born. Since 1998, Chinese manufacturers have been able to successfully train a large workforce to conduct the skilled glass blowing techniques required to manufacture the evacuated tubes.
