Solar Heating Is Viable
By Chris Costanzo

For over thirty years, Randolph’s Ed Butler has been installing solar heating systems for his clients, thereby combining his passion for renewable sources of energy with his profession as a plumber.

A casual wanderer through Randolph might stumble upon the house where Butler lives with his wife Cynthia at the end of a remote and isolated road. A quick glance confirms the "green" orientation of its inhabitants. One sees a tiny solar panel that generates electricity to run an attic fan and another that runs a water pump. There is a small wind-generator to charge automobile batteries. On the roof of the barn is a large array of solar panels that absorb heat for the family’s water.

Born in Connecticut, Butler became a plumber’s apprentice immediately after completing high school in Hartford in 1969, and got his own plumber’s license in 1975. By then, he had become very interested in renewable sources of energy, and his interest intensified during the national gasoline shortages in 1974. In 1976 he and a former high school classmate became partners in the firm, Sunrise Solar Systems.

Soon Butler and his partner were busy creating state-of-the-art systems for energy-conscious consumers. Among these was President Jimmy Carter, for whom Butler and his associates installed an array of thirty-two solar panels at the White House.

Butler transferred his operation to Vermont in 1992. By then he had worked in all the New England states, and he particularly liked Vermont’s attitude that encourages the use of renewable energy resources.

"I also loved the state’s beautiful landscape," he says. "It was a move that made sense in terms of my interests and profession."

Despite the electric-generating solar panels that power some appliances in his own home, Butler limits himself professionally to the installation of thermal (heat-preserving) rather than electric systems.

The idea behind thermal systems is really quite simple. Heat can easily dissipate, so the key to the effective use of thermal energy is to take the cumulative heat of the sun and store it efficiently for later use.

Butler’s sophisticated thermal systems employ water reservoirs to store heat from the sun in a mechanical process. Electrical systems, on the other hand, store solar energy chemically in batteries. Although electric systems are effective for running appliances, they are not efficient in preserving the more massive amounts of energy needed for heating, he said.

The principle of thermal storage has been known since ancient times. Architects and builders have always understood that a house with a full southern exposure will heat up during the day and keep some of the heat inside for an appreciable time after sunset, even in winter. The energy saved by a well-designed southern exposure is appreciable, even if the heat does eventually dissipate during the night. But modern technology, such as Butler uses, allows one to concentrate and store heat more efficiently and for a much longer time than merely letting a house warm up during the day.

Typically in one of Butler’s systems, the light of the sun raises the temperature of a heat-absorbent material in a solar panel on the roof. Small pipes embedded in the panel are filled with a non-toxic heat-transfer fluid. The fluid flows into larger pipes that run to a lower part of the house. The hot fluid eventually passes through coiled tubes inside a water tank, thereby heating the water. For a typical family, such a tank, usually located in the basement, might have a capacity of about 80 gallons—enough for baths, laundry and dish-washing.

"It is vital to have good insulation," Butler notes. The pipes leading down from the roof are heavily insulated to prevent heat loss, as is the tank itself. An electric pump keeps the heat-transfer fluid circulating between the heat collectors above and the water tank below.

"The thermal system in my home serves almost 100% of my family’s hot water needs from May through September," Butler says. A very small amount of outside energy is necessary for the pump, which, according to Butler, requires less than 100 watts of electric power.

Due to Vermont’s cold climate, such a system needs to be supplemented from fall into early spring with other sources of energy. For that reason, the hot water tank will contain a second coil that transfers additional heat to the water from a conventional secondary system fueled either by electricity, propane, oil or wood.

But even in winter, there are still significant savings from the stored solar heat.

"Over the whole year, solar energy accounts for at least 60% of my water heating requirements," he said.

Butler estimates that such a system in Vermont will repay the typical owner in roughly eight or 10 years for the costs of material and installation. From then on, one’s hot water requirements will cost virtually nothing.

"The system does requires some minor maintenance, mainly in flushing out and replacing the heat transfer fluid every few years or so," Butler says. He noted that it’s easy to do and inexpensive.

Of particular interest to Butler is the use of "vacuum tubes," developed by NASA, as an alternative to flat heat-gathering panels on rooftop solar arrays. The difference is that the vacuum in the tubes is a superb insulator that preserves much of the heat absorbed from the sun’s radiant energy that would otherwise be lost by air convection around the array.

"It gives the vacuum tubes some advantage on overcast and cool days," Butler explains, "but is more expensive."

Butler has already installed vacuum-tube arrays on a number of houses in the region.

"Some people particularly like their high-tech look," he notes. He added that neither a vacuum tube array nor a panel array has to be on the roof itself. At homes where a roof is shielded from the sun, or where the roof surface is not facing south, an array can be mounted at a more favorable spot, even on the ground.

Energy from the sun need not be limited to heating one’s bath or laundry water. Some of Butler’s installations also provide space-heating for the house. Such systems are somewhat more elaborate, as in the home of Amy and Scott Berkey in Randolph village.

The Berkeys’ system, installed by Butler, employs a 640-gallon water tank in the basement. The huge tank is embedded with a coil that carries the heat-bearing fluid from an array of 60 vacuum tubes on the roof through the water in the tank, thereby heating the water to very high temperatures. But in this case, the water in the tank is not used directly by the household. It stays indefinitely in the tank and serves solely as a heat storage reservoir.

When the household requires heat, a pump sends water from a separate closed system through a coil in the tank, where it is heated. It is then pumped through tubing under the floorboards of the house to provide radiant heat.

Another coil in the tank carries city water to be heated for bathing and laundry. For supplemental energy, particularly in winter, the Berkeys have a wood-heated boiler. They also have a backup propane system for use when the family is away on cold days.

One of the attractions of solar energy lies in financial incentives granted by state and federal governments to those who install solar-energy systems. According to the Vermont Department of Public Service, the state now makes available significant financial incentives for thermal equipment purchased and installed in Vermont. Details are at a website maintained by the Renewable Energy Resource Center (www.rerc-vt.org).

The site also provides a calculator to help estimate one’s savings from a thermal-energy system.

"Vermont is among the greenest in the country in supporting the growing trend towards renewable energy sources," Butler notes.

Butler’s clients interviewed by The Herald are delighted with their solar-thermal systems. Not only do they save money, but, as Amy Berkey said, "I like knowing that we have really reduced our fossil fuel consumption for our family’s energy needs."

____________