Officials at the Alaska SeaLife Center in Seward previously spent upward of $1 million a year to heat the massive building at the edge of Resurrection Bay. But now the center’s heating system runs on something a little cheaper and readily available just a stone’s throw away.
Thanks to the installation of a new seawater heat pump at the center, officials expect to save big on energy costs — up to $15,000 per month in the winter — through the system that will also reduce the amount of fuel oil the center used to burn, further reducing its carbon footprint. Officials also hope the system will be a blueprint for others in Alaska, where applicable, and inspiration for others to think outside the fossil fuel box.
SeaLife Center Operations Manager Darryl Schaefermeyer said center officials first started looking at the seawater heat pump technology in 2009. After securing about $700,000 in federal and state funding for the system, it was first used in July 2011. The units were officially commissioned in April 2012 after a winter testing period.
The system takes advantage of the fact that the center already pumps large quantities of seawater into the building for various uses in animal habitats, research tanks, and pools, among others.
One of those pumps is now dedicated to supplying enough seawater to feed the heating system. The first stop for the seawater, Schaefermeyer said, is to a heat exchanger in the building.
“On one side we have the salt water and on the other side is a mixture of fresh water and 20 percent propylene glycol,” Schaefermeyer said. “... That mixture then picks up the same temperature that’s in the seawater.”
That same-temperature mixture, which is 48 or 49 degrees at this time of the year, is then piped to a boiler room to two compressor heat pumps while the sea water returns to Resurrection Bay, he said.
“What happens is this 20 percent water glycol at 48 or 49 degrees goes into the heat pumps where it comes into contact with a refrigerant and that boils at a very low temperature,” he said.
When the refrigerant boils, it vaporizes and then that vapor is compressed, Schaefermeyer said.
“When you compress a vapor it gets very hot and so that hot vapor then goes into a different loop of water, this time it is just pure water that heats that water to anywhere from 105 degrees to 130 degrees and we can set and regulate the temperature in that range,” he said.
That hot water is then used to preheat domestic hot water and coils in air handlers to heat the inside of the building. The advantage is that for every unit of electrical energy it takes to run the pumps and the system, the center gets two to three units of heating energy back, he said. The system produces no waste, he said, and works within all the temperature ranges Resurrection Bay waters see, including near-freezing in deep winter.
Currently the center is looking at expanding the system to heat outside habitats, research pads and the concrete in front of the building to keep off snow and ice in the winter months, Schaefermeyer said.
But, Schaefermeyer thinks the technology could help in other coastal areas like Seward that aren’t on the gas distribution system and see high winter energy costs, or spread throughout cities like Seward to other businesses.
“I kind of have a dream — Seward is kind of a compact community to eventually try doing district heating with a system like this,” he said. “You could even heat your streets and sidewalks so do don’t have to deal with all that extraordinary costs of winter snow removal.”
Andy Baker, owner of YourCleanEnergy based in Anchorage and lead designer of the SeaLife Center’s project, said that vision, however, is currently a little out of reach. It’s an exciting new energy development to Alaska, Baker said, but there are many barriers to entry making it easier for individuals or specific facilities to use, rather than whole communities.
“At this is time it is emerging technology,” he said. “We are starting to see these systems going in and so like any new bicycle, it will take a while for it to take off. It is specific areas and specific facilities.”
Restrictions on where such systems can be placed include water bodies that stay ice-free year round, are mostly free of marine silt, are in areas that have a relatively low cost of electricity and have a client or facility that has the capability to design, install and maintain the system.
There are two other systems in the area using similar technology, but instead rely a different water source, such as lake water, Baker said.
“So all three of those systems are working successfully, but all of those clients are pretty motivated, they can take care of things and can maintain the systems, they are also the investors,” he said. “They weren’t given those systems. They went out and decided to invest and they were very careful about who did the work, how it was done and they are the caretaker types.”
But the possibility still exists for the system to heat what Baker called a “mini-district.”
“The only way this could be moved faster is if you had a very visionary city administrator or mayor who said, ‘Look, we are going to do this, we are going to put this in the downtown of Seward,’” he said.
If that situation could be worked out, it would lower the cost of heat which could spur business development and increase density in the business district, all of which benefit a city and its tax revenue base, Baker said.
“So the technology works, the money (in government grants) is there, but what is missing for a district loop is the political will or the social organization that is unified that can agree to commit to this source of heat,” he said.
However, that’s all a “huge leap” for someone to understand or imagine who has never seen or heard of a system like the one at the SeaLife Center, Baker said.
“Think right before electricity was invented and suddenly Thomas Edison comes along and says, ‘Hey, we are going to run wires down the street and we want you to connect all your buildings,’” he said with a laugh. “People would be going, ‘No way.’”
Brian Smith can be reached at firstname.lastname@example.org.