Virginia Man Creates “Sand Battery” Solar Heating System

Use the term “solar heating” in a conversation, and your listener will likely think of “solar water heating” (or, maybe, a solar thermal system). But solar space heating certainly isn’t a new concept, even if it’s not the first thing to come to mind: passive solar orientation makes use of it, and numerous designs exist for collecting the sun’s warmth for heating homes and buildings… from the relatively simple DIY plan to more complex technologies.

Dave Stets, co-owner of Richmond BySolar in Richmond, Virginia, has created one of those more complex plans. His solar heating system for his home in Henrico County is built on the concept of high-mass solar heating, and involves storing heat collected from solar panels in a bed of sand until it’s ready for use. According to the Richmond Times-Dispatch,

Eight solar panels, 8 feet tall and 4 feet wide, collect the sun’s warmth in Stets’ backyard, just beyond the patio and bird feeder.

That heat warms a nontoxic form of antifreeze in the panels. Moved by a pump, the hot liquid leaves the panels in a pipe that runs underground. That heat warms a 15-cubic meter bed of sand…

The hot sand warms a separate, water-filled pipe, which runs to Stets’ house and provides heat under the floor.

While use of high-mass solar heating isn’t particularly new, Stets’ system was designed around the question “How can you use Summer’s heat to warm the house in the Winter?” Previous systems placed the sand bed directly below the house, making it impossible to “turn off” in the Summer. Stets, along with Professor James T. McLeskey Jr. of Virginia Commonwealth University, moved the sand bed away from the building, and use the water-filled pipes to control the use of the stored heat.

The system isn’t for sale… yet: Stets would like to eventually develop it into a product he can sell through his company. If you’d like to get a look at the system, check out this infographic, or read the Solar Today magazine article that Stets wrote about the system.

Jeff McIntire-Strasburg is the founder and editor of green blog and product comparison engine sustainablog. If you’re interested in using the sun’s heat in your own home, check out our current listings of solar water heaters and solar pool heating systems.

Image credit: Theodore Scott at Flickr under a Creative Commons license

Posted on March 11th in Solar Products by Guest Author.