Raising the Roof with Solar Thermal

Winery owner Frank Reinhold, who grew up on the land where the winery is located, purchased two German manufactured stills for vodka production earlier this year. Though the stills are some of the most advanced machines for distilled spirits production, Reinhold was soon faced with the fact that they aren't energy efficient and produce approximately 1,000 gallons of 160-degree wastewater during a day of operations.

His cost overruns were looking ominous until Steve Leighton of Leighton Enterprises, the roofing contractor who was installing a steel standing-seam roof on the barn at the winery, suggested a BIST system developed by his second company Dawn Solar.

Reinhold wasn't afraid to try something new, particularly if the system offered a way to put the wastewater to good use.

"Everything that this winery does has been at the cutting edge," he said.

The system designed by Dawn Solar takes the concept of radiant floor heating, which is used to maintain an ambient temperature inside a building, and puts it in the roof. Polyethylene tubing, PEX, is fit into metal purlins, which are used to support the roofing material between the rafters, and the whole set-up is positioned between the attic roof and the outside roof covering. A steel standing-seam roof acts as a solar thermal collector to heat the purlins, which in-turn heat the water that is circulated through the PEX tubing.

The water normally warms to between 60 and 80 degrees Fahrenheit above the ambient air temperature, which is a lower temperature than if a traditional solar thermal collector was used for the system. Because the roofing material will radiate heat after it reaches a certain temperature the system is self-regulating, which helps to keep the water from stagnating in the tubing. The water is then circulated in the building to help achieve an ambient indoor temperature.

The BIST at the winery is a bit different because its main purpose is as a cooling mechanism in the winter for the vodka still. Even if the BIST heats to 90 degrees on a sunny winter day, it will cool the water from the stills enough to be useful throughout the building's radiant heat system.

In the summer when the still isn't running, Reinhold can use the nighttime cooling properties of the BIST and store the water for circulation through his home and business during the day.

Everything about the BIST system designed by Dawn Solar is familiar to building, plumbing and roofing contractors, according to Bill Poleatewich, COO for the company.

The New Hampshire Sustainable Energy Association organized a seminar with Poleatewich and Reinhold at Flag Hill Winery as a way to get the word out about the product, and to let people know that the winery is a demonstration project for the system.

"We're not at all concerned that we're introducing something foreign to (contractors)," Poleatewich said.

While the BIST at the winery is used partly for its solar thermal capabilities, it is also used to cool the 160-degree wastewater that is produced by the vodka stills. It was the wastewater problem that first made Leighton think of a radiant heat solution for Reinhold. Luckily, the barn roof was still in the first stages of production so it was easy to retrofit a BIST into the plan.

Reinhold said the Dawn Solar system has already helped to solve his wastewater issues, but deciding to go with the plan was a fine balance between necessity and funding.

Housing developers had already made numerous attempts to get him to sell pieces off of the 125 acres of land that he owns for his vineyard and winery. Land sales could have helped pay for the solar thermal solution for his business and home, which is estimated to cost US $37,000 just for the tubing systems in the roof and floor, and the circulation system to keep the water moving. But Reinhold just couldn't bring himself to sell any of the land he had grown up on.

"I assumed a certain degree of responsibility," he said. "I don't think (my father) intended for me to turn around and break it up into house lots."

Conservation easements and donations to the Rockingham Land Trusts helped him to not just fund US $750,000 of the system price, but also to protect the land from development beyond its current agricultural use. A conservation easement means that Reinhold has to follow some specific guidelines for the appearance of his land, however. Because the Dawn Solar system is "invisible" when looking at the outside of Reinhold's home and business the BIST was accepted by officials from the trust.

The Flag Hill Winery isn't the first project for Dawn Solar. Poleatewich said the company has worked on three private installations in New England, and has pending contracts in Connecticut, Arizona, Florida, California and New Jersey. Many of the contracts they have are for new construction, though the winery is proof that a retrofit is certainly possible.

Most BIST projects installed by Dawn Solar are meant to collect the heat that is captured in the roof and distribute the heat to the rest of the house, not act as a cooling system for waste water from a still.

Dawn Solar systems are such a mix of construction, plumbing and roofing that the company is looking for contractors who will act as dealers for the sale and installation of their building-integrated solar thermal. Contractors need to know where the best places on a roof to install the tubing and purlins are, so they have to acquire a basic knowledge of solar applications before they start working.

With a product that has four-years of testing and development behind it, plus the benefit of a demonstration site, Poleatewich said he is confident there is a market available for Dawn Solar's building-integrated solar solution.

"We really see the potential of this system as going well beyond the residential applications," he said.

The Flag Hill Winery's solar thermal-assisted vodka will soon be sold throughout New Hampshire liquor stores under the label General John Stark Vodka.