The Alaska SeaLife Center is now heated almost completely by renewable energy thanks to a system that uses heat from an unconventional source.
The Seward research institution and aquarium announced Friday that after three months of testing, it has gone from heating 60 percent of its building with renewable heat to 98 percent. Its heat pump system uses energy from Resurrection Bay's seawater.
The facility has been using heat pump energy since first installing a system in 2011. Project designer Andy Baker said the original system covered most of the building's hot water and radiant floor heat, but was not able to get hot enough to power baseboard heaters in the rest of the building.
But that's changed thanks to the new system that was installed in December 2015. The second phase of the system still uses the heat pump technology, but instead of using a synthetic refrigerant similar to coolants in standard air conditioners, the new heat pumps use carbon dioxide instead.
The new system pulls heat from relatively cold water in Resurrection Bay and compresses it into heat capable of warming water and buildings. It uses carbon dioxide refrigerant, which can compress the heat to higher temperatures than the synthetic version.
Baker, owner of the Anchorage renewable energy consulting firm YourCleanEnergy, said the synthetic refrigerant not only couldn't heat up as much as the carbon dioxide-based version, but it also had a great degree of greenhouse warming potential should it leak out into the atmosphere.
He said the carbon dioxide also has some greenhouse warming potential, but to a much lesser degree.
"The fact that you could use the same gas to solve the problem is pretty cool," Baker said in a phone interview Friday.
Center special projects director Darryl Schaefermeyer said in an email the new system alone has "virtually eliminated operation" of electric boilers, saving the organization $4,000 a month. The whole system combined saves the center about $15,000 a month in total by eliminating use of several oil-fired boilers.
The new carbon system cost about $656,000, according to thecenter. A majority of the cost was offset by a $537,640 grant from the Alaska Energy Authority emerging energy technology fund.