Solar thermal system a window to the future
June 9, 2011
JOINT BASE LEWIS-MCCHORD, Wash. -- Thereâ€™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 facilityâ€™s roof are the first of their kind on JBLM. The panels work alongside the buildingâ€™s gas-fired hot water heater to heat the buildingâ€™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.
â€śIn the summertime, we can be completely dependent on the solar system, whereas in the wintertime weâ€™re pretty dependent on the gas-fired system,â€ť said Sandy Bonderman, a project manager and principle engineer with Seattle-based Notkin Engineering. â€śBut as it nets out on an annual basis, 40 percent of our energy comes from the sun.â€ť
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 regionâ€™s traditionally wet and cloudy weather, while others say itâ€™s because of the abundance of hydroelectric power. But experts think solar power should be a viable renewable energy option here, too.
â€śThe sun comes up every day,â€ť said Richard Sanchez, a project engineer for the U.S. Army Corps of Engineers who has overseen the facilityâ€™s design. â€śIt produces energy every day. Even if it is only 19 percent, itâ€™s still producing energy.â€ť
Bonderman and fellow engineer John Rowlandâ€™s design portfolio includes the Museum of Glass in Tacoma and Seattleâ€™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.
â€śThe RFPs are starting to address (renewable energy) as options, which is how they introduce every new form of construction,â€ť said Ike Holmes, owner of Vet Industrial, the facilityâ€™s building contractor. â€śThey start by options, and they see how itâ€™s done and learn from that and then they become requirements.â€ť
â€śIt is just a matter of time before youâ€™ll see these everywhere,â€ť Holmes said, â€śsome sort of renewable energy.â€ť
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.
â€śBig Army is saying ... we need to get off of fossil fuels, period,â€ť Sanchez said. â€ś(That) itâ€™s a matter of national security.â€ť
While the new system at Nisqually isnâ€™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.
â€śIf youâ€™re going to (be) heating water only and not the whole building, then (solar thermal) is pretty efficient,â€ť he said. â€śIf you combine the two together, then youâ€™re better off.â€ť
Sanchez expects improvements in the efficiency of alternative energy production will lead to its proliferation on military installations across the U.S. Itâ€™s only a matter of time.
â€śIt depends on how fast the gas prices (rise),â€ť he said. â€śIt could be a year or two based on what weâ€™re looking at.â€ť
Ingrid Barrentine: firstname.lastname@example.org