Image by Rube Goldberg Inc.The Santa Fe Civic Housing Authority wants to install photovoltaics and ground-source heat pumps at the Villa Alegre public housing project, according to the top story in today’s New Mexican.
Although I generally shy away from debates about energy technology, because they frequently overshadow the more important discussions of system ownership and economics, this proposal is so bad that it makes for a good discussion.
Photovoltaics convert the sun’s energy into electricity, while ground-source heat pumps convert electricity into heat. So viewed from end to end, this project will convert sunlight into heat using a two-step process – the first one involving silicon wafers, wires, circuit breakers, power converters, and phase-synchronizers, and the second one using compressors, refrigerants, heat exchangers, and fans.
The problem, of course, is that there are far simpler ways of converting sunlight into useable heat, including by running water through a black garden hose on a sunny day. I’m not suggesting that we should heat Villa Alegre with garden hoses – the point is that when simple, low-technology means are available, you are always better off avoiding the high-tech approach.
Rudy Gallegos, the Deputy Director of the Housing Authority whose name is suspiciously close to Rube Goldberg's, assured me this morning that his experts tell them it’s the right way to go.
But no amount of “expert” advice, no accrual of LEED bonus points, and no level of government funding can make the conversion of sunlight to electricity and then back to heat a good idea. Adding unnecessary complexity is always a problem, even if experts tell you otherwise and a government grant will pay you to do it.
Assuming the City and its housing authority can accept that they got it wrong this time, then they also have an opportunity to get it right. As the nonprofit Local Energy has long held, getting it right means starting by stating your values, and then selecting technologies that best apply those values in your community.
We must value energy projects that make efficient use of local resources, and that recycle the money we are paying for energy back into our community. Our research shows that for heating, this can best be accomplished with commonly used hydronic heating systems in which the water is heated with simple, low-cost solar collectors and low-technology, high-efficiency cordwood boilers. Such systems can be supplied and installed by local companies, financed locally, and fueled by the sun and by the local foresters that are working hard to maintain the health of our surrounding woodlands.
On behalf of all the local entrepreneurs who might benefit from opportunities to participate in heating our beautiful city, I have just one message for city officials: We are here for you, and we await your call.