PHOTOVOLTAIC = Sexy Solar, THERMAL SOLAR = Not So Much
I can relate to the lack of respect and attention that thermal solar systems (TSS) experience both in the marketplace and within our state and federal governments. As a teenager, my best buddy was this good-looking, smooth-talking guy and standing next to him, I kind of blended into the wallpaper. I wasn’t ugly and/or dull, but next to my buddy the ladies couldn’t see my attributes. So goes it for thermal solar systems!
Photovoltaic (electricity generating) solar systems have become the “sexy solar” systems both in the press and in the legislatures around our country. Don’t get me wrong, producing electricity via the sun’s energy is awesome and deserves attention. My concern is that thermal solar systems may not be getting the attention they too deserve, and thus opportunities may be missed.
Thermal solar systems that generate hot water for domestic use as well as supplemental heat are generally a fraction of the cost of a photovoltaic system. Although thermal systems can’t create an income-generating source as photovoltaic can, I don’t believe it is realistic for the average homeowner to think they will be getting checks from their local electric utility for the unused kilowatts that a residential photovoltaic system could generate. Small residential photovoltaic systems are just that - small - and as a result can’t generate income and fulfill unrealistic expectations of potential buyers.
On March 31, 2009, the governor of New Jersey enacted the Residential Development Solar Energy Systems Act which will require residential home builders to offer a solar energy option to potential home buyers in developments of 25 or more units. I believe thermal solar systems are the best choice. TSS can be installed by properly trained plumbers and HVAC installers. Sixty vacuum tubes or four flat-plate panel collectors can do most, if not all, of a typical domestic hot water requirement for a four-person family, as well as supplement low-temperature heat (approximately 30%) and high-temperature heat (approximately 10%).
TSS collectors are much more efficient than photovoltaic (PV) collectors. Depending on the collector, a TSS can convert 50% to 70% of the sun’s energy into hot water. PV collectors convert somewhere between 12% to 15% of the sun’s energy into electricity. Hot water can be stored at low or no usage periods in an insulated tank with less than one degree loss per hour. PV systems that are large enough to produce more electricity than the home can use can be connected directly to the “grid” and excess kilowatts sold to the local utility. However, it’s more typical in small PV systems that electricity may be stored in a battery, or a series of batteries, which require space, maintenance and can be very expensive.
Thermal solar systems have very little maintenance issues. A circulator is virtually the only moving part and it, as well as the other system component parts, are familiar to all plumbers and HVAC technicians because a TSS is a traditional hydronic system. The only thing different is that instead of a boiler and/or water heater, the panel is your heat source. TSS are simple systems that can do a BIG job at a relatively low installed cost compared to complicated PV systems.
In my role as the training manager at The Wales Darby Learning Center I have plumbers and HVAC technicians calling me daily to ask when our next “solar” class is scheduled. I have learned to ask the question, “You do understand our class is for thermal solar and not photovoltaic?” Unfortunately, I have found that people are using the word “solar” in an all-encompassing way. Early on, I had a few guys in my class ask, “When are we going to talk about systems that produce electricity?” It brought me back to my younger days when I would get phone calls from pretty girls asking me if I thought my buddy liked them. Ugh!
There are signs that the spotlight is starting to shine (pun intended) on TSS. The feds finally came around and lifted the $2,000 limit on tax credits related to residential TSS installations and put it in line with what had been standard for PV systems (up to 30% of installed cost) since the enactment of the 2005 Federal Energy Act.
Eventually my good-looking, smooth-talking friend moved away and I started to get some attention (and I stress some) from the female population.
Hang in there, thermal solar fans. I’m proof that every “dog” has his sunny day!