One of the first home improvements Rachel and I made when we purchased our condo here in Cambridge this spring was a solar hot water installation on our rooftop.The system we had put in uses vacuum tubes, a newer, more efficient type of solar collector than the black box flat panels of old. As a writer covering energy and the environment in Cambridge and China, I'd spent the past three years tracing this new and exotic technology back to the factories and cities in China where they are surprisingly commonplace.
I first read about the tubes three years ago in a story in the Boston Globe. A family in Newbury, MA was using a massive installation to provide hot water and heat for their giant barn of a house. A photo that went with the story showed their installation covered in frost on a cold winter day. Somehow, despite the cold, the tubes were still kicking out 120 to 160 degree water.
