Sunday, August 8, 2010

Solar Thermal Systems Gain Popularity

Solar hot water is getting a new day in the sun.

While most of the recent publicity has focused on its higher-tech sister, photovoltaic production of electricity, the solar thermal business is also growing.

"Solar thermal" means liquid is heated by the sun's rays and then used in homes, businesses or institutions. Most commonly, it produces what engineers call "domestic hot water," or what comes out of the hot water faucet.

But it can also be used in some cases for heating the air in a building, primarily through radiant floor systems. Another approach is solar walls, which involve using the sun to heat exterior surfaces and capturing the warmed air to supplement the heating systems.

The basic technology is an old one and fairly simple, said Ron Kamen, who is head of sales and senior vice president for EarthKind Solar in Lake Katrine and who also serves as president of the industry group the New York Solar Energy Industries Association.

The hot water approach is easily adaptable to home use and not nearly as expensive as the photovoltaic approach, Kamen said, though he advocates and handles both.

"There's 10 times as much solar hot water installed as solar electric," he said. "Everyone else in the world pretty much does it. It's a very simple technology, very straightforward. It's the most cost-effective method."

"There's a tremendous need for residential. Hot water is about one-third of the average family fuel bill," Kamen said.

Among the convinced are Robin and Rashmi Sen, both architects with a practice in New York. They have designed and are building a house and studio in Salt Point where solar hot water is used to supplement both domestic hot water and space heating.

They got into green design in some Brooklyn projects, Robin Sen explained, and then brought the approach home.

"We wanted to put in as much as we could in terms of using the least amount of fossil fuels," he said. The house burns no fuels on site, but uses electricity. It has a hybrid heating system that consists of a geothermal heating-cooling system and a solar hot water array ground-mounted near the house.

The house has a ceramic floor that becomes a heater when the solar-heated water is run through it. Sen said that the solar water panels can heat the house adequately when outside temperature drops to as low as 50 degrees. Lower than that, and the geothermal kicks in to help.

Interest is spreading. Contractor Joseph Malcarne has expanded his business into the installation of these units and put some atop his house in Staatsburg.

The solar association list of members is growing, as contractors from various trades get interested in offering such work.

Alteris Renewables has opened a two-person office with hopes of growth at TechCity, the same Lake Katrine facility that houses EarthKind and a growing number of solar-related businesses.

A major solar hot water system was dedicated Monday at Benedictine Hospital in Kingston, for which EarthKind was the source.

It was part of a $428,000 federally funded solar technology and energy efficiency project at the Kingston, Benedictine and Margaretville campuses of the Health Care Alliance. Rep. Maurice Hinchey, instrumental in obtaining the funds, said it was aimed at energy efficiency and cutting carbon emissions.

The Solar Energy Consortium and engineering students at the State University of New York New Paltz assisted.

Environmental consciousness is one stimulus for the solar movement, as is federal and state aid. But the economy hasn't been one.

Elaine Lacy, marketing director for EarthKind , said the slow economy has been felt.

"I think more people are hesitant," she said. "But people are still interested, still calling."

The savings in energy costs are a key selling point. The recession put soaring fuel costs on a holiday, but in the long term, the economics favor alternative sources, Kamen said.

He said fuel prices would rise, and cited the need for energy independence. And as for oil, "It eventually is going to run out. It's just a question of time."

Perhaps the biggest hurdle to jump is the capital cost of the systems. A two-panel solar hot water rig and its associated gear can cost a homeowner about $8,000 to $10,000 and would save about half to two-thirds of the operating costs of getting domestic hot water.

But that upfront cost can soon be offset not only by the savings, but by the hefty federal and state tax credits that can be claimed on the next tax return.

A credit is a dollar-for-dollar savings off one's tax liability. The federal credit is 30 percent. So, for example, a $10,000 system cost brings a $3,000 credit. The state offers a 25 percent credit, which would be good for $2,500. Combined, the credits are $5,500, cutting the homeowner's final cost to $4,500 in this example.

The cost recovery through savings is fastest for people who heat their water with electricity, Kamen said. The second-fastest is oil and the longest recovery is with natural gas.

The final cost recovery may come when the house is sold and fetches a higher price because its energy efficiency is a selling point.

Kamen said solar hot water for heating air is an emerging field. It's being done, as Sen's case shows, but mostly in new construction. Solar hot water does not get up to the range needed for baseboard heaters, for example. But engineers are finding ways to integrate solar hot water with other techniques in combination systems that use solar as a pre-heater and some other gear to handle the rest of the temperature rise.

An obvious shortcoming is that solar is weakest when you need it most, in the winter, and strongest when you need it least, in the summer. A system sized to perform well in winter will produce waste heat all summer. Kamen said some installations use that heat for swimming pools and hot tubs.

Research is aimed at finding ways to turn the excess heat into energy that can then run cooling systems. It's been done, but not yet in a cost-effective way, Kamen said. These sun-driven coolers will most likely be used in commercial buildings first.

Straight solar air is getting used, too. At the Army's Fort Drum in upstate New York there is what's claimed to be the nation's largest installation of solar walls.

There, 50 SolarWall skins have been installed on 27 buildings to collect hot air that is then pumped inside to handle part of the heating. The company says tests on one system saved about $1,000 a month in natural gas costs.

The New York Solar Thermal Consortium, a group of institutions and businesses, has begun drawing up a "Solar Thermal Road Map for New York State" with the aim of growing from about 500 systems now to about 20,000 in a few years and half a million by 2020. That would create 20,000 jobs, too, Kamen said.


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