Beginning next week, the state of Massachusetts will give about 60 state homeowners grants totaling $1 million, in a pilot energy program that uses solar thermal water-heating technology to provide their homes with hot water and energy savings.
While the state wants to find out how solar thermal works as an energy-saver, West Tisbury resident Diane Hartman already knows. “My propane use has declined from 700 to 200 gallons a year since 2008. The savings on fuel is more than the cost of the home equity loan I used to install the system,” Ms. Hartman said last week.
Her system was installed in 2008 by her friend, Tim Twombly, who is also president of SunWater MV, which he formed in 2005 specifically to sell and install solar thermal energy systems.
“I was retired from an engineering career but when I became aware of this technology in 2004, I formed SunWater MV as a dedicated solar thermal business,” he said last week during a tour of the Hartman residence.
“This (solar thermal rebate) is a program we have been waiting for. It helps the homeowner to directly decrease the cost of getting started with solar. The rebate, coupled with federal, state and many utility incentive programs, can contribute nearly half the cost of a system,” he said.
The pilot residential rebate program, entitled Commonwealth Solar Hot Water, is offered by the Massachusetts Clean Energy Center (MassCEC), an agency that implements state energy initiatives.
MassCEC will begin accepting applications mid-month for a the new program, to help Massachusetts residents adopt solar thermal water-heating technology. For more information, homeowners may go to the MassCEC website (www.MassCEC.com) or call Mr. Twombly, at SunWater MV (508-560-0009).
Mr. Twombly is the only NABCEP-certified solar thermal installer on the Island, and one of only four in the Commonwealth of Massachusetts. ”This is a grant, basically. Cash, not a tax credit. There is $1 million available on a first come-first serve basis,” he said in an interview.
He said a solar thermal system for an average-sized house costs about $15,000. He estimated that homeowners could defray half the cost using MassCEC grants and other rebates. Mr. Twombly said SunWater MV has installed eight solar systems since the company’s inception and worked on retrofitting three other systems.
Mr. Twombly explained that thermal solar systems differ from conventional solar systems in that the thermal system uses evacuated tubes, which he described as “large thermos bottles” rather than photo voltaic (PV) elements to gather and store sunlight for conversion into electricity to heat water.
On the roof, the solar panels are similar in appearance to PV systems but the benefits of thermal come from what’s inside the round tubes on the panel, Mr. Twombly said. Panels can be installed either vertically or horizontally.
Each tube houses a five-foot heat pipe made from materials used by NASA in its spacecraft. The entire collector also contains 24 ounces of a non-toxic anti-freeze solution, rather than being filled with water, he said.
Mr. Twombly has built a mini-system with tubes that he uses for demonstrations. Removing the two-foot collecting rod from a tube, Mr. Twombly placed one end of the rod in a saucepan of boiling water and noted that the other end began to warm immediately.
“PV is the first thing people think of in solar systems but it isn’t necessarily the best alternative. I maintain that insulation and window technologies are the first (savings) step for retrofitting. There are eleven thousand homes already standing on the Island. Solar thermal has the potential to fulfill twice as much of homeowners energy needs as photo-voltaic,” he said.
Mr. Twombly also believes customized refrigeration and air-conditioning elements is a viable alternative, using the thermal solar system. Mr. Twombly said Abracus, the thermal solar system he favors, can offer a three- to four-year payback on investment compared with seven or eight years for photovoltaic systems.
Solar thermal provides more efficiency and delivery speed than PV, Mr. Twombly said. “You can only get 10 per cent of the energy that hits the roof with PV. The best solar thermal system may offer 70-80% efficiency as a collector and converter and for storage of energy,” he said.
“Solar thermal tubes do not require direct sunlight to gather energy so they work on cloudy days and in winter. The tubes are rounded so they are able to gather sunlight, regardless of the sun’s angle in the sky and the vacuum promotes energy retention,” he said.
“There are many more advances to come. SunWater’s job is to find the best solutions. There are great combinations of alternative energy sources available now, such as thermal solar and heat pumps, that offer great savings to homeowners,” he said.