The oldest, biggest and most efficient solar application is heating water. Solar hot water systems have been around in one way or another ever since Roman times. But it has only been over the last 100 years or so that solar hot water systems have become popular -- driven by high energy costs, environmental consciousness, and lower solar equipment costs.

The most popular application of solar heating is for solar domestic hot water, or DHW. These systems generally use a metal and glass solar collector mounted on the roof, and a plumbing system that circulates cold water up to the roof so that it can be heated up to normal home water temperatures. Solar DHW systems are reliable, and make the best economic sense when water is heated by electricity or propane.

My guest this week is Peter Bliss, VP of Sales and Marketing of SunEarth. Since 1978, SunEarth has been designing, selling and installing solar hot water collectors, components and packaged systems. They have been through several generations of the “solar coaster” as solar thermal technology evolves, incentives come and go, and energy prices continue to rise. Please Listen Up to this week’s Energy Show on Renewable Energy World as Peter talks about the economics of solar DHW, as well as the technology and policy changes that can make these systems even more popular.