by David Flint
Solar panels seem to be sprouting everywhere, on farms, firehouse roofs and residential homes. The Town of Stephentown is looking into installing them on the Town Hall, the Town Garage or at the Transfer Station. Stewart’s convenience stores has embarked on putting up a 600 kilowatt system on the roof of its manufacturing and distribution center in Saratoga County.
[private]Many of these installations are photovoltaic (PV) systems that produce electricity. With PV panels at record low prices, fuel at high prices, concerns about global warming and generous incentives and tax credits from the government, many are convinced that it makes a lot of sense right now to start producing electricity from the sun. Some PV systems now are also combined with new high efficiency heat pumps that can use relatively small amounts of electricity to produce hot water for domestic use and for baseboard and radiant floor heating.
But PV isn’t the only game in town. Solar hot water or solar thermal systems have been around for a long time, and they are not going away anytime soon. Terry Moag, a NYSERDA-eligible installer who owns The Radiant Store in the Rensselaer Technology Park in Troy, said that while solar thermal may not be the most exciting technology, it does a very good job for a modest amount of money for a very long time. “It has its own little niche,” he said, providing a low cost entry point to solar technology for many people. “And it’s fun,” he added, “to make your own energy and be independent of the grid and the oil man.” Moag made a decision years ago to install only solar thermal systems. But he recognizes that one size does not fit all, and, depending on a number of factors, he might recommend that a home owner or business go with PV, and he will refer them to the right companies that can do that.
Moag points out that the investment required by PV is considerably greater than for thermal. A typical 6,000 watt system for a residential home would run $12,000 to $20,000. The 30% federal tax credit would reduce that to between $8,400 and $14,000. With savings on electricity of about $900 a year, the payback time would be between 9 and 16 years.
A solar thermal system for the average home, Moag said, would run to about $6,000 before credits. But solar thermal in New York is eligible for 25% state tax credits as well as the 30% federal credits, which, along with NYSERDA incentives, would reduce the cost by about 55%. In the northeast these systems typically provide 50% to 80% of hot water needs. So for an investment of about $2,700 you could save about $800 per year in fuel costs, making your payback time just over three years.
Moag said these installations are relatively simple and require little maintenance. The panels don’t degrade as do PV modules. The antifreeze fluid should be replaced every 5 to 7 years at a cost of about $125.
Anita Henry and Tom Quimby built their home on Schmich Road in Stephentown in 2008. Henry is a certified Home Performance Consultant and knew that she wanted an energy efficient home. They had Moag design the hot water heating system which includes radiant heat under the kitchen, bath and basement floors. Two 3’x 6’ solar collector panels on the roof provide heat for most of the domestic hot water and much of the radiant heat. Solar heating is supplemented by a propane powered boiler and a wood stove. The solar panels collect heat from the sun in a closed loop of piping filled with an antifreeze solution, and that heat is transferred to a collector tank in the basement via a heat exchanger. Controls in the system monitor performance and flow. Henry and Quimby say they are extremely happy with the system. Throughout most of the year the hot water they use is free. They have paid only $40 for propane over the past two heating seasons to supplement the solar system. In the first few months after the system was installed they realized that something was wrong because the propane heater would kick in continually. Moag’s people quickly corrected the problem with a simple adjustment to the controls.
In considering putting solar panels on the roof they were a bit apprehensive about roof leaks. These fears have been allayed by the extensive flashing that comes with the panels and the careful and thorough job done by The Radiant Store installers.
Bill Zimmerman lives not far down the road in New Lebanon. Zimmerman had a solar hot water system installed way back in 1983. A lightning strike took it out in June 2009.
He toyed with the idea of a PV system to produce electricity but decided the payback time was too long. Rather than repair old technology he called upon Moag to install a new Velux solar hot water system. He said the old solar panels had to be raised at a steeper angle above the roof level to effectively catch the sun during the winter. The new more effective panels, two of them, lie flat on his roof and the new system is a great improvement over the old one. Even on a cloudy day in winter, Zimmerman said, the temperature in the panels is 15 to 20 degrees warmer than the ambient temperature. In the summer it may be up to 30 degrees warmer. In fact, on a sunny day in summer the system’s pump will run often just dumping the heat out of the panels to prevent overheating. The pump is pretty small, however, and uses little electricity. Zimmerman keeps his furnace shut down from mid-May to September, restarting it just occasionally to keep condensation down. He believes the solar heat saves him at least one delivery of oil per year.
In winter Zimmerman said he does sometimes use a roof rake to clear the panels of snow. The sun will eventually work through the snow and get the system going, but it takes a little more time.
Zimmerman said he is very happy with the system. It’s almost four years old now, and there are no problems. “The Velux system is extremely well designed,” Zimmerman said. “The installation crew was knowledgeable, meticulous and dedicated to doing the best job possible.”
NYSERDA last year gave their Solar Thermal Program Outstanding Achievement Award for 2011 to The Radiant Store. This was for “performing more installations through the program – and displacing more kilowatt-hours – than any other installer in New York State. Since the program’s inception in December 2010, The Radiant Store has installed 50 systems, displacing an impressive 264,001 kilowatt hours of electricity.”[/private]