Solar hot water (SHW) is a huge market globally, but an almost untapped market in the U.S., as recently reported by GTM's Herman Trabish.

It's a topic we've covered in depth of late at Greentech Media. Here's a roundup of our recent coverage:

According to Sunnovations CEO Matt Carlson, there are approximately 100 million residential water heating systems in the U.S., and just under half use electricity, fuel oil or propane. “I’m looking at a market of 50-million-plus homes that don’t use natural gas to heat their water,” he said. “That’s a pretty sizeable market, and that’s where the opportunity is.”  Here's a profile of Sunnovations.

The growth potential for solar thermal is huge. But governments will have to create stable, long-term policy frameworks for solar thermal that include economic incentives and remove barriers. They will also need to set quality-control standards and fund and support research, development and demonstration (RD&D) efforts (especially in the area of small scale heatstorage) that will bring commercial production to much higher levels within a decade.

The recent Intersolar show in San Francisco featured a number of SHW firms. This article looks at SHW technology and government incentives for SHW.

The U.S. military is waking up to solar hot water. The Eneref Institute, founded in the wake of the September 11 attacks to help shift the nation’s energy use, has recently taken up the cause of solar thermal and brought it to the Pentagon where, due to budget constraints, it has been well received by a military eager to save money and energy.   

Cogenra, a Khosla Ventures-funded firm, combines solar hot water with photovoltaics and seems to be gaining some traction.

Third-party financing has completely changed the solar photovoltaic landscape -- opening up new customer sectors, new investment areas and huge entrepreneurial opportunities. Could third-party financing do the same for solar hot water? Skyline Innovations, a third-party financing SHW startup, thinks so.