Solar Thermal & The Shirley MacLaine Complex

Feb. 14, 2013
The news is good, for PV, it seems. What about SDHW or solar thermal? How is that looking for 2013 and beyond? Perhaps solar has one more reincarnation left. I recently caught up with Bob ‘hot rod’ Rohr, educational & training manager for Caleffi, North America. Milwaukee, and picked his brain on the topic of the health of solar thermal.

This past year I have read more than one story about the solar industry’s fragile state, or about its impending demise. In fact, I’ve even read headlines that read something like “Solar Thermal is Dead.” I mean, solar thermal was left for dead in the 1970s and has made quite a comeback lately. Just ask the Europeans. Higher energy prices force Europeans to look for alternative energy sources, and solar energy seems to be doing pretty well across the pond.

The interest is there. According to the Solar Energy Industries Association’s (SEIA) nationwide survey of recent voters on their attitudes toward solar, results show that about nine out of ten Americans (92%) think that the United States should develop and use more solar energy.

In some comforting news from the last report from SEIA, Q3 U.S. solar energy saw growth in PV, and witnessed record residential installs. In fact, the third quarter 2012 was the third largest on record for the U.S. solar industry and raised the total installed capacity through the first three quarters of the year to 1,992 megawatts (MW)- already surpassing 2011’s annual total of 1,885 MW. There were 684 MW of photovoltaic (PV) capacity installed in Q3 2012, representing a 44% increase in deployment over the third quarter of 2011. SEIA forecasts that close to 1,300 MW of PV capacity will be installed in the fourth quarter of 2012 alone, bringing the total for the year to 3,200 MW.

The news is good, for PV, it seems. What about SDHW or solar thermal? How is that looking for 2013 and beyond? Perhaps solar has one more reincarnation left. I recently caught up with Bob ‘Hot Rod’ Rohr, educational and training manager for Caleffi, North America, Milwaukee, and picked his brain on the topic of the health of solar thermal.

JM: Can you give specific examples or regions in the U.S. that SDHW is thriving?

HR: Yes, the residential solar thermal market has slowed down since the second coming back 2007, 2008 and 2009, but the commercial solar thermal (ST) side has really increased. The best use of solar thermal is large or at least consistent loads. Clever solar marketers and installers realize correctional facilities, military, high occupancy lodging and many food processing and bottling business are still prime targets. As an installer, one large job can be more attractive and profitable then a dozen residential projects spread across the state.

JM: Are there still rebates going on of which contractors can take advantage?

HR: Yes the Federal Tax Cedit is still available. Various states still have excellent rebate and finance programs. Also some of the power providers have programs. These programs come and go as the funding is used up, so check the dsire site every few weeks. They do a good job of updating the lists. Search the state and local programs at  Database of State Incentives for Renewable Energy is the website. Make sure you spell it correctly or a surprise awaits you.

JM: Any new technology coming down the pipeline that would reassure the notion that solar is definitely going strong?

HR: One technology that has caught my attention is a PV to electric water heater system. As I understand it, the PV module wires directly to a DC voltage element in the tank. You can choose how many KW of collector to include depending on your DHW loads. Several advantages include no piping, glycol, pump, insulation and heat exchanger. The issue of stagnation and dump zones is eliminated. The goal I have heard is starting at $3500.00 installed! This could be a game changer for residential systems. A five-year finance program makes this very easy to sell. As I understand the concept, PV directly to the tank without grid tie in eliminates utility permits, liability insurance requirements from the utility, special net meters, multiple permits and inspections, etc. A licensed electrician and roofer could team up for these installs. I think this system has some merit.

JM: Any news on a solar thermal/PV hybrid system?

HR: I see these as a compromise system similar to an SUV; I don't see a lot of traction in this technology. I have seen some clever agriculture industry applications. Placing a collector over the chicks in a brooder house was one. The thermal warms and a small fan moves the energy down to the nests.

JM: Anything new from Europe that we (Americans) are taking a closer look at?

HR: I still have hope for high temperature collectors to drive AC chillers for residential air conditioning. Evacuated tubes could provide this temperature to drive absorption chillers. I have seen some small two to three ton systems on the market, but the price is still a bit too high to go mainstream. Ideally, the solar thermal would cover DHW, possibly some heating and a good portion of the summer AC load. The high summer solar availability matches ideally with cooling loads. It could also lighten the load on the electrical grid and eliminate brownouts, as the climate seems to get warmer every year now.

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