The growth of renewable energy in Alaska: opportunities 'waiting in the wings'.

• Author: White, Rindi
• Position: SPECIAL SECTION: Energy & Power

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Wind. Water. Geothermal. Air. Seawater. The sources of energy for Alaska communities seem to be growing each year. In some ways, Alaska has become a testing ground for new renewable energy projects. In Seward, the Alaska SeaLife Center uses seawater heat from Resurrection Bay and high-efficiency R134a heat pumps to send heat through pipes throughout the building, heating exhibit pavements, offices, conference rooms, and everything in the facility.

Four new transcritical carbon dioxide (CO2) heat pumps were integrated into its seawater-source heat pump system, which provides 98 percent of the heating for the 120,000-square foot aquarium and research center.

SeaLife Center Special Projects Director Darryl Schaefermeyer says the updated system means the center is now avoiding 1.2 million pounds of carbon emissions each year.

But the center didn't start out with a plan to reduce its carbon footprint. Its goal was more economical--to cut what had become $15,000-per-month utility bills. For a nonprofit that runs on donations, grants, and gate fees, utility costs were overwhelming.

The first thing the center did was purchase an electric boiler, which bought them some time to figure out a longer-term solution.

In 2010, the SeaLife Center designed and installed a heat pump system that uses seawater from Resurrection Bay, heats it, and runs it through a heating loop through the building. Integrating the heat pumps helped the center cut out the expensive-to-run oil boilers, but the synthetic-refrigerant heat pumps were unable to heat the water hot enough to provide heat for the center's offices and labs.

SeaLife Center consultant Andy Baker says the office and lab baseboard heating is designed to run on 160 degrees in the winter; most heat pumps can only heat up to 130 degrees. But at a convention in Vancouver, B.C., Baker learned about smaller, Japanese-made heat pumps that use carbon dioxide as a refrigerant and could heat water to 194 degrees. By incorporating four of the smaller heat pumps, Baker says, the SeaLife Center could offset 98 percent of the conventional oil and electric boiler heat load.

The SeaLife Center applied for and won an Alaska Energy Authority Emerging Energy Technology grant of $550,000 in 2014 and installed the four CO2 heat pump units in December 2015.

"They work really well--we have eliminated the electric boiler for most of the time," Baker says. And the center, which bought about fifty-seven thousand gallons of heating oil a year, hasn't bought any since 2012.

"This is the first known integration of these CO2 heat pumps in the United States to offset a large conventional boiler system," Baker says. "There are only fifteen CO2 heat pump units like this in the United States and the Alaska SeaLife Center now has four of them." The CO2 heat pumps are designed to heat smaller spaces and are popular in Japan and Europe, where energy prices are higher. Incorporating them was a challenge, he says.

"It wasn't that you could just put them in there, plug and play. You had to figure out how to design these loops so that they would work properly," Baker says.

In addition to higher heating, the CO2 heat pumps don't use synthetic refrigerants, relying instead on twenty pounds of CO2 in each of the four units. The difference is important because, eventually, all synthetic refrigerants leak. "It goes into the atmosphere and persists for a really long...