17 March 2012
Solar heating and cooling project saves New York high school more money than anticipated
UNIONDALE, N.Y. – A new solar heating and cooling system installed at Kellenberg Memorial High School is working so well it has saved the Catholic school in Uniondale, N.Y., about $12,000 in utility costs so far this year. “And that’s on the conservative side,” said Brother Gary Eck, who has taught math at Kellenberg for 16 years and is the school’s solar project coordinator. If it hadn’t been such a mild winter, he said, that figure would have jumped to $25,000 had the school needed the same amount of heat it used last year.
The system, which has been operating since Dec. 15, features an array of 115 SPP-30A evacuated tube solar collectors made by Solar Panels Plus, a leading U.S. manufacturer of solar thermal, hot water, space heating and cooling products.
“During some of the recent sunny days that we have enjoyed, the system has been bringing in more than 800,000 BTUs per hour,” Eck said. To put this into a layman’s perspective, he continued, 100,000 BTUs (British Thermal Units) equals one therm, a commercially used measurement of heat energy. On average, the school pays about $1.25 per therm of natural gas. “So that translates into $10 of gas per hour that we’re not buying,” said Eck, estimating the solar array is producing about 10 percent of the energy used by the school.
The Kellenberg Solar Thermal Collector Project system is designed to use sunshine to make hot water to help heat the three-story, 275,000-square-foot facility in the winter. In the summer, the hot water will fuel a high-tech absorption chiller to air condition parts of the school. During the shoulder seasons of spring and fall, the harvested solar energy will be used to help produce the school’s hot tap water. Overall, the renewable solar energy will reduce the consumption of natural gas for heating and the use of electricity for cooling, saving the school tens of thousands of dollars in utility bills each year.
Eck said he expects the amount of energy produced to rise in the summer. “Amazingly, on 20 degree days that are bright and sunny, we’re turning out water near 160 degrees F,” he said. “This is still the winter season when the sun is low. Come spring and summer when the sun is higher in the sky, the panels will be even more effective.”
Money for the project was provided through stimulus funds from the American Recovery and Reinvestment Act by way of a New York State Energy Research and Development Authority grant for renewable energy and energy efficiency. In 2010 NYSERDA approved the school’s proposed solar thermal collector project, which had a price tag of $944,755.
The choice of the more technologically advanced SPP evacuated tube collector over flat panels was easy, Eck said. “First, they are more efficient. Secondly, we have experience with a small set of four SPP panels that we installed as a test project several years ago. We have had no problems with outdoor leaks forming or circulation water freezing. And in this part of the country where subfreezing temperatures are par for winter,” he said, “that’s an important consideration.” The SPP collectors, he added, are further protected with a glycol antifreeze solution.
He also praised the durability of the evacuated tubes, citing a freak hail storm that hit the area last spring. “We had nickel-size and quarter-size hail come down and none of the tubes were broken,” Eck said.
On a personal note, he added, the SPP tubes are compliant with the Buy American Act. “The tubes are assembled in the U.S., which I think is great,” Eck said. “They didn’t need to be to get the grant but it certainly was a positive factor in meeting grant guidelines.”
One of the challenges of this project was the circa 1965 facility’s “marginally acceptable” roof where the collectors are now installed. The structural engineer determined the collectors had to be mounted to withstand wind loads of 120 mph or more. Racking systems that involved 15 tons of steel or lighter racks that required upward of 1,300 holes for fasteners could have done the job, but neither was suitable for the structure.
Composite Technologies of Calverton, N.Y., came up with a specially designed solution that involves a racking system that uses reinforced-fiber panel technology and epoxy. Dubbed the RMORs RR roof rehab racking system, it had the required tensile strength, with none of the weight of steel. The preassembled mounting frames securely adhered the collectors to the roof without penetrating it.
As part of the project, an assortment of instruments including temperature gages, flow meters and BTU meters have been incorporated into the system to allow students to access operational data. Eck is currently developing a website which will ultimately be used as part of various science classes’ curriculum. “Students will be able to gather data from a working solar application and analyze their findings to determine what solar energy means on a practical level,” he said.
In addition to the solar thermal project, over the years Kellenberg has made several energy efficiency upgrades, including retrofitting lighting fixtures, switching to more energy-efficient light bulbs, installing motion detectors to control lights and adding insulation.
For more information on Solar Panels Plus, which is headquartered in Chesapeake, Va., or any of its products, visit www.solarpanelsplus.com or call (866) 576-5277.