Sea Life Center taps clean, plentiful energy source

Posted on: November 6, 2009 | musiclover | 1 Comment | Print Article | Rate Post:

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Most of us probably wouldn’t imagine the seawater in Resurrection Bay to be warm. Not warm enough to heat local buildings during the cold winters. But we would be wrong. In fact, Resurrection Bay is a wonderful source of energy that stores large amounts of solar energy from the summer months that could help heat buildings in Seward while also reducing our dependence on more costly, polluting forms of energy.

The Alaska SeaLife Center, located right on the bay, is preparing to put into operation a pilot project that will provide supplemental heat for one of its existing large air heating units, and outdoor pavement, using an innovative heat transfer process that employs high efficiency heat pumps, said Darryl Schaefermeyer, the center’s general manager.

The center recently received an Emerging Technology Grant from the Denali Commission to build and install a seawater heat pump system capable of meeting 25-30 percent of its building’s heating needs. The system could save the center $66,000 per year in heating oil costs (at $2.52/gallon), and reduce the building’s Co2 emissions by 587,000 lbs a year, Schaefermeyer said.

“It’s a very good source of green energy. It’s as exciting to me as wind energy,” Schaefermeyer said. “Think of it as using solar energy, ocean-warmed by the sun… (it’s) renewable every year.”

Seward City Manager Phillip Oates very proudly announced the grant received for the sealife building, which the city owns and leases to ASLC. Other parties who could benefit from observing the seawater heat pump project, and how well it works, includes the Alutiiq Pride Shellfish Hatchery, who could use the method in raising larvae and algae cultures needed for shellfish production; the UAF School of Fisheries and Ocean Sciences in Seward, who may consider converting its own heating system to employ seawater pump technology; and Kenai Fjords National Park, which is hoping to develop a visitor center and administration building downtown to meet the Department of Energy’s carbon neutral “net-zero” standard.

 (Photo: Darryl Shafermeyer stands by PVC pipes below sea life center)

ASLC already brings sea water into its building through two 24-inch diameter seawater intake pipes that draw flow from a depth of 275 feet. The center uses the water for its aquaria. “It’s the life blood of the place,” said Schaefermeyer, taking this SCN reporter on a tour of the various massive energy/water systems located in the basement level of the building. The sea water is stored in a tide level intake basin, and is pumped to its fish and marine mammal tanks through large white PVC pipes. The center also pumps fresh water for its fresh water tanks and research laboratories. Additional PVC pipe systems carry contaminated waste water away from the tanks, which is treated with ozone and expelled.

Data gathered at ASLC from 2003-2008 show raw seawater temperatures in Resurrection Bay reaches a maximum of 52 degrees Fahrenheit in October and November, and drops to a minimum of 38 degrees F in April. Temperatures average around 41F in July to 49F in early winter, to 38F in early spring.

The center will employ the new pump to “lift” latent heat from raw seawater and transfer this heat energy into air handler units and pavement heating exchangers at a temperature of 12- degrees F. The basic concept is that the raw sea water, at temperatures ranging from 38F to 55F, would first be pumped through a heat exchanger containing propylene glycol, a vegetable-based antifreeze in common use in northern latitude commercial and residential heating systems. Then the water would go to an electric powered compressor, where it would be heated further to 120F, and finally through looped pipes to heat the facility and its outdoor pavement. After being used as a heat source, the raw seawater would be distributed to ASLC aquaria and research tanks or simply be expelled back into the bay.

Using an energy recovery formula engineers typically apply to heating units to measure their efficiency, ASLC discovered that the new pump will have a coefficient greater than three, which means that every unit of electricity put into the process (i.e. running the pump), yields greater than three units of energy in return, making this method both cost effective and efficient, Schaefermeyer said.

Coastal communities with access to seawater from ice-free bays and with reasonably priced electricity have the potential to replicate this innovative heating system, Schaefermeyer said. The center would be ready to showcase the system to its own visitors and to interested facilities and communities. In coastal communities that have warm seawater temperatures extending into the winter months (like Seward), the potential exists for expanding this technology into a district heating system, such as those used in coastal communities in northern Europe. Large seawater heat pumps supply warm source water to buildings along a buried insulated loop pipe that is tapped to serve customers along the route. These customers can use their own “off the shelf” heat pumps to lift the warm source water temperature to 120 F for building heat and domestic hot water.

The City of Seward could build its own saltwater plant to heat city buildings, local businesses, or even run it through pipes buried below city sidewalks downtown, reducing winter snow removal, Schaefermeyer said.

“It would be a technology that we would be interested in,” said Jeff Mow, superintendent of the Kenai Fjords National Park. For five years, the park piloted a hydrogen fuel cell project at Exit Glacier that garnered much public attention due to its remote location. The fuel cell ran flawlessly for a couple of months, but the technology moved on, and the park ran out of funding to keep up with the changes, Mow said. Soon, they will be able to observe first-hand how the ASLC’s heat pump system works.

Other Alaska communities where this system may be cost effective include Kodiak, St. Paul, Dillingham, and Sitka, Schaefermeyer said. Seawater heat pump system could motivate coastal communities to develop small electrical power generation systems such as wind or hydro to provide the electricity needed to power them, he said. They would shift dependence on heating oil to electricity as the prime mover of heat, making this system an alternative to conventional fossil fuel heating systems.

Seawater heating has been successfully employed in northern Europe for nearly 20 years: Ocean-warmed seawater provides heat for 41,000 people living on a military base in Bodo Norway; Vartan Ropsten has the largest seawater heat pumps on the planet in Stockholm, Sweden; STATOIL Research Center in Trondheim, Norway provides district heating with seawater; and the City of the Hague is building a new seawater plant to heat 750 reconstructed homes in the village of Duindorp, along the North Sea Coast.

(contact heidizemach@yahoo.com)

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