Solar thermal system a window to the future
June 9, 2011
JOINT BASE LEWIS-MCCHORD, Wash. -- There’s a not-so-new technology in use on Joint Base Lewis-McChord that is helping to provide hot water at the 60,000-square-foot Nisqually Medical Dental facility.
Solar power has been around a long time, but the 24 brand new solar thermal panels on the facility’s roof are the first of their kind on JBLM. The panels work alongside the building’s gas-fired hot water heater to heat the building’s domestic hot water. On some sunny days, the panels have the capacity to heat the water entirely on their own.
While absorbing heat from the sun, an antifreeze-like fluid is pumped through each black panel and then back into a large tank inside the building. Once in the 1,200-gallon tank, the heat from the glycol antifreeze passes through a heat exchanger and into the domestic water.
“In the summertime, we can be completely dependent on the solar system, whereas in the wintertime we’re pretty dependent on the gas-fired system,” said Sandy Bonderman, a project manager and principle engineer with Seattle-based Notkin Engineering. “But as it nets out on an annual basis, 40 percent of our energy comes from the sun.”
While visiting the facility a couple weeks ago on a cool, semi-cloudy day, Bonderman found the panels were producing heat at 180 degrees, which translated into 150-degree water.
That result surprised even her.
Some believe the lack of solar technology in use in the Pacific Northwest can be attributed to the region’s traditionally wet and cloudy weather, while others say it’s because of the abundance of hydroelectric power. But experts think solar power should be a viable renewable energy option here, too.
“The sun comes up every day,” said Richard Sanchez, a project engineer for the U.S. Army Corps of Engineers who has overseen the facility’s design. “It produces energy every day. Even if it is only 19 percent, it’s still producing energy.”
Bonderman and fellow engineer John Rowland’s design portfolio includes the Museum of Glass in Tacoma and Seattle’s Experience Music Project, but the two said they have never worked on a project that incorporated a solar thermal system. They began designing the system after the request for a proposal required solar technology be incorporated in the project.
“The RFPs are starting to address (renewable energy) as options, which is how they introduce every new form of construction,” said Ike Holmes, owner of Vet Industrial, the facility’s building contractor. “They start by options, and they see how it’s done and learn from that and then they become requirements.”
“It is just a matter of time before you’ll see these everywhere,” Holmes said, “some sort of renewable energy.”
Both Bonderman and Sanchez say all of the alternative energy requirements are the direct result of several federal acts. The bipartisan Energy Policy Act of 2005 encourages the use of solar thermal technologies to help reduce U.S. dependence on imported fossil fuels, and the 2007 Energy Independence and Security Act requires all new federal buildings be independent of fossil fuels by 2030.
“Big Army is saying ... we need to get off of fossil fuels, period,” Sanchez said. “(That) it’s a matter of national security.”
While the new system at Nisqually isn’t a full-time alternative energy solution, it is a start.
Sanchez believes another solar technology " photovoltaic " is more efficient because the photovoltaic panels take energy from the sun and immediately convert it to electricity.
“If you’re going to (be) heating water only and not the whole building, then (solar thermal) is pretty efficient,” he said. “If you combine the two together, then you’re better off.”
Sanchez expects improvements in the efficiency of alternative energy production will lead to its proliferation on military installations across the U.S. It’s only a matter of time.
“It depends on how fast the gas prices (rise),” he said. “It could be a year or two based on what we’re looking at.”
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