Saturday, December 24, 2011

A New Kind of Solar System

Solar Skies in Alexandria was the featured attraction of the Minnesota Department of Employment and Economic Development’s (DEED) Minnesota Solar Manufacturing Supply Chain Roundtable on Wednesday, November 16.

Randy Hagen, president and CEO of Solar Skies, said his product reaches as far as Hawaii, Guam and Guantanamo. Solar thermal collectors are assembled right here in Alexandria but not a lot of businesses in the city – or state – are using them.

“When people think solar, they think of places where the sun is shining with warmer temperatures,” Haugen said. That’s a misconception he would like to dispel. Recently, Canadians have been showing a lot of interest in Solar Skies.

‘The goal is to create a solar sector in the state,” said DEED Representative Kari Howe.

A discussion on using solar thermal energy to heat water was followed by a tour of the Solar Skies plant where solar thermal collectors are assembled.

SOLAR THERMAL WATER HEATERS

The collectors produced by Solar Skies are extremely efficient. Kurt Koegel provides sales and technical support for Solar Skies. Koegel said the collectors are “pretty much at the max for efficiency.”

Solar energy is constantly evolving, he said. The cost of producing a product needs to be worth the return and right now it’s reliable and efficient.

Rather than being consumed with 100 percent dependency on solar thermal for a family’s hot water needs, Koegel said the aim is to produce half of their annual hot water load with solar thermal in addition to the existing method such as gas, electric or geo thermal.

A family of four uses 80 gallons of hot water per day, requiring 5,550-kilowatt hours to heat with electricity. By harnessing the radiant heat produced by the sun, it cuts down on the energy needed to heat the water, thus reducing the monetary cost. An added benefit is a reduction in carbon dioxide released into the atmosphere.

“I hate the term ‘green’,” Koegel said, “We’re doing it smart.”

One question raised during the discussion was how this technology will benefit residents in the Northland during the winter months and if there is cause for concern of the system freezing up.

Collectors can still gather the sun’s energy when it isn’t directly overhead. Solar thermal collectors are installed at a tilt equal to the latitude of the location. In Minnesota, that tilt is 45 degrees. Solar thermal, at this time, is viewed as a supplemental energy source so when the conditions aren’t prime for the solar tank to produce hot water, a person can rely on their previous method as a back up.

“Cold weather will affect the collector very slightly,” Koegel said, adding that, “these units are designed to last over 30 years.”

In the winter he recommends adding antifreeze, propylene glycol specifically. “Propylene glycol is nontoxic and food safe, it’s the same stuff used in ice cream,” Koegel said.

There are two types of water heating units – a flow back system and a pressurized tank. The pressurized system has a higher cost for materials but less cost for labor. Pressurized systems are necessary when there is not a proper pitch on the roof for flow back, Koegel explained.

On average, the cost for a residential configuration with installation is $8,000 to $12,000. If the system is included in plans for a newly constructed home, the cost could be less.

Rebates and incentives are offered for using solar energy. A $10,000 Minnesota Solar Hot Water Rebate helped with the costs of implementing the solar system project at The Wellstone Apartments in Hudson, Wisconsin. In Lake City, Minnesota a couple qualified for a 30 percent federal tax credit and a $1,500 Minnesota State Solar Thermal rebate for adding their solar system.

BEHIND THE SCENES

Six men were busy welding, fastening and assembling solar conductors as Solar Skies general manager Shannon Snell walked the group of Minnesota business professionals through the warehouse.

The building isn’t overrun with solar collectors. Snell said they don’t make a lot to keep in stock.

Sheets of translucent glass a bit smaller than a sliding glass patio door are framed and sent to the next assembly station. The tempered glass is tested at 350 pounds per square inch and is durable enough to withstand wind, rain, snow, sleet and hail. The glass is tough enough that technicians can lay their tools on it without worry of damage to the product.

“I like to keep the dollars local,” Snell said. The glass currently comes from Ohio and Tennessee. “I honestly haven’t been able to find a supplier locally at remotely the same price,” he said.

A copper tube with “fins” welded to it is affixed to the glass. The fins are also copper and coated with a substance Snell called “black magic,” which contains a selective clear-coat designed to absorb solar energy. The piece is welded in Jacksonville, Fla., where one of only two companies in the United States is equipped to handle the task.

“We’re looking quite aggressively to perform the weld in-house,” Snell said.

Snell recently saw laser welding done in Germany that allows use of materials other than copper. Koegel noted that when the U.S. was taking a break from pursuing solar energy in the 1980s, Germany continued and can be credited with many of the advances made to date. A lot of European countries are using a copper tube with aluminum plates, resulting in a lower cost for more product.

Hagen noted that Woodland Elementary in Alexandria does have a solar thermal system to demonstrate to students how it works, but the community has not yet begun using the technology. He hopes the DEED roundtable will help get the message distributed throughout Minnesota.

To learn more about Solar Skies, visit www.solarskies.com. Solar thermal collectors can be seen on the Solar Skies building at 106 Donovan Drive in Alexandria.

Solar thermal saves

Solar thermal collectors are 50 to 70 percent efficient in converting the sun’s energy into heat.

Solar thermal water heaters can provide up to 70 percent of hot water per year.

One four-by-10-foot collector can produce 40 to 60 gallons of 120 degree water per day in Minnesota.

One system for a family of four can displace as much Co2 as a car driven 12,000 miles per year.

SOURCE: http://www.echopress.com/event/article/id/90098/

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