It's a technology that has been used in California in one form or another since the 1800s. But, like its photovoltaic counterpart, solar hot water heating in the state is about to ramp up production in a big way with the signing of bill AB 1470 by Governor Arnold Schwarzenegger last week.

"The goal of the program is to install 200,000 hot water systems on businesses and homes throughout state of California, see reduction in price and similar to the California Solar Initiative...the vision of this program is to create a mainstream market for solar water heating technologies as well." -- Bernadette Del Chiaro, Clean Energy Advocate, Environment California