Tag Archives: Energy

Air Source Heat Pumps in Southeast Alaska

How an air source heat pump works. Photo credit: U.S. Department of Energy.

Air source heat pumps (ASHP) are a heating appliance that act like a refrigerator in reverse.  Where a refrigerator removes heated air from its interior and transfers it to the room, an air source heat pump extracts heat from outside a house, and transfers it to a home’s interior. Using an ASHP in colder climates seems counterintuitive, but the truth is that “cold” outdoor air still contains heat, and an ASHP uses electricity to “step up” that heat to a temperature useful for space heating. Until recently, ASHPs have been used in areas that only experienced mild winters.  However, ongoing advances in technology have resulted in ASHPs that can be installed in colder climates.

Southeast Alaska is a promising candidate for ASHP heating appliances, because it has a milder climate than the rest of the state and access to affordable hydroelectric power. Because ASHPs take some heat from the outdoor air and require less electricity than electric baseboards, they have the potential to reduce heating costs for homeowners who previously heated with electric appliances.

However, there is still uncertainty about the performance of ASHPs in cold climates, and about the barriers to their adoption in Alaska.  CCHRC is planning to explore the opportunity of using ASHPs in Southeast Alaska in a new project: Southeast Alaska ASHP Technology Assessment.  We will conduct a literature review, interview installers, distributers, and ASHP owners, create an inventory of existing ASHPs in Alaska, and model their economic and heating impact.  If you are interested, look for the Technology Assessment on our website in early 2013!

Read CCHRC’s Ground Source Heat Pump assessment here.

What is a ground source heat pump?

A heat pump harvests energy from the ground to use for space heating for your home.

A ground source heat pump (GSHP) is a space heating appliance that uses electricity to convert geothermal heat to a temperature that can be used for indoor heating. They are common in the Lower 48 and quite popular in Europe. There are also several GSHP systems in Alaska, including commercial systems at the Juneau Airport, Weller Elementary School in Fairbanks, and the Alaska SeaLife Center in Seward. Fairbanks has more than 10 residential systems as well.

In the winter, ground source heat pumps work like refrigerators in reverse. Instead of taking heat from the inside of the refrigerator and rejecting it outside, a GSHP gathers heat from the ground, steps it up to a higher temperature using a compressor, and then “rejects” it inside a house. In the summer, some GSHPs can run in reverse mode to provide air conditioning – taking heat from a house and rejecting it to the ground. The main “fuel” for a GSHP is geothermal energy, but it uses electricity to run the compressor. Since the electricity is only acting to boost the geothermal heat (which is free), heat pumps are more efficient than electric heating appliances.

A GSHP consists of 3 parts: the ground loop, the heat pump and the distribution system. The ground loop gathers heat from the ground. It consists of loops of pipes buried in horizontal troughs or vertical boreholes. A pump moves a fluid through the pipes. As the fluid travels, it is warmed up by geothermal heat from the soil and returns to the heat pump with a higher temperature than when it left. Back at the heat pump, the fluid from the ground loop passes its heat to a refrigerant, causing it to evaporate into a gas. The refrigerant fluid then passes through a compressor and its heat can be “stepped up” before it transfers the heat to air or water for the distribution system. Heat pumps can work with a forced air distribution system or a radiant hydronic distribution system, however they generally are not capable of producing hot enough water for baseboard hydronic systems.

Ground source heat pumps are considered a partially renewable technology, because the heat they take from the ground comes from solar and geothermal sources. They are entirely renewable if the electricity they use comes from a renewable source, such as solar or wind. Heat pumps are also very safe to operate, because there is no combustion. They can, however, be expensive to install because you have to excavate land or drill to establish the ground loop. Talk to an installer if you think a GSHP might be right for you.

For more information on ground source heat pumps, see a report by the Cold Climate Housing Research Center and the Alaska Center for Energy and Power: http://cchrc.org/docs/reports/Ground-Source-Heat-Pumps-in-Cold-Climates.pdf. It covers the performance, cost and payback of GSHPs in various regions of Alaska.

How to heat your home using the cold ground

Our new report shows that ground source heat pumps are an effective and affordable technology for parts of Alaska, including Fairbanks, Juneau and Seward.
In this video, CCHRC researcher Colin Craven discusses how heat pumps work and what you have to think about before installing one in Alaska.

Press Release: Report shows heat pumps economically viable in Alaska

laying the ground loop at Weller Elementary School

Ground source heat pumps offer an economically viable heating option in some places in Alaska, according to a new report from UAF’s Alaska Center for Energy and Power and the Cold Climate Housing Research Center.

The study found that the systems, which extract heat from the earth, are technically and economically viable in areas with high heating costs and low electric costs. The report, funded by the Denali Commission, offers the first in-depth assessment of ground source heat pumps in Alaska.

“There recently has been quite a bit of excitement about ground source heat pumps, as people are seeking more affordable heating options. Our report helps explain the technology in the context of Alaska, and analyzes its potential throughout the state,” said co-author Colin Craven, head of product testing at CCHRC.

There are roughly 50 heat pumps in Alaska, including high-profile commercial installations at Weller Elementary School in Fairbanks and the Juneau Airport Terminal as well as several residential installations around the state. A heat pump transfers energy from the earth or water to use for heating or cooling. The system consists of underground tubing filled with heat-transfer fluid, an electric pump and a heat distribution system.

Researchers reviewed the industry in Alaska, interviewed ground source heat pump owners and assessed the performance and economic viability of the technology in five cities: Fairbanks, Anchorage, Juneau, Bethel and Seward. They compared the cost and performance of heat pumps with traditional heating systems in an average-sized new construction home in each city. They found that heat pumps could match or beat other heating systems in Fairbanks, Juneau and Seward.

“Even though the ground source heat pumps have high up-front capital costs, which is what deters people from installing them, they end up costing less over 15 years just because you save so much money on annual energy costs,” said Dominique Pride, graduate researcher at ACEP and co-author of the report.

The systems are most economical in Juneau and Seward, where heating oil is expensive and electricity costs are low. They also potentially make sense in Fairbanks, which has more expensive electricity than Southeast and Southcentral but also higher heating demand and costs, thus more room for energy savings.

The analysis found the pumps are not economical in Anchorage, which has low heating and power costs thanks to inexpensive natural gas. And they are not viable in Bethel and most of rural Alaska because of its extremely high electricity costs.

In addition to economics, researchers looked at cold climate considerations on system performance, including the impact of ground source heat pumps on soil, as extracting heat could create more permafrost if the ground temperature doesn’t recover in the summer. Researches plan to install a pump at the CCHRC next year to further study the effects and viability of the systems.

CONTACTS: Julie Estey, 907-590-0879. Molly Rettig, CCHRC communications coordinator, 907-450-1772, molly@cchrc.org. Marmian Grimes, UAF public information officer, at 907-474-7902 or via e-mail at marmian.grimes@alaska.edu.

Developer hopes to capitalize on wind power near Delta Junction

From The Fairbanks Daily News-Miner, Sunday, September 26, 2010:

A Fairbanks developer said Tuesday he hopes he can build a 25-megawatt wind farm near Delta Junction despite limited avenues for public aid.

Mike Craft said his firm, Alaska Environmental Power, is working with Golden Valley Electric Association to study how to best feed wind power into Interior Alaska’s transmission grid.

The work parallels planning by Golden Valley for a separate wind farm near Healy.

Craft told a chamber of commerce audience Tuesday he hopes the integration studies will lead to power-sale agreements between his firm and the utility. He said Golden Valley previously agreed to a smaller, pilot sale agreement following construction of two smaller turbines at the Delta site.

“(It) made it possible for us to come on line with these two turbines. That helped us a lot,” Craft said. He said the turbines, the largest built with state aid, have produced 134,000 kilowatt-hours of electricity.

Craft, a builder and residential developer, started looking to enter the wind power business roughly three years ago. He approached public officials last winter for help with his project and received lukewarm responses but said Tuesday he chose to continue and hopes to install 16 GE turbines near Delta.

University of Alaska gets $3 million grant for rural hybrid energy

From The Associated Press, Friday, September 17, 2010:

A University of Alaska group will receive $3 million to study options to optimize wind-diesel hybrid energy systems in rural Alaska.

The Alaska Center for Energy and Power, based at UA Fairbanks, was awarded the grant by the federal Department of Energy.

The university says Alaska already has systems pairing wind turbines with diesel power plants but many are not performing as designed due to extreme weather and remote, distributed grid systems.

Research paid for by the grant will investigate technical issues related to power stability, long-term energy storage and control systems to better use fluctuating wind power.

Research also will investigate turbine performance in cold climates and remote locations and challenges such as icing, foundations in poor soils and remote monitoring.

Wind power company in 'talks' with AVEC

From The Tundra Drums, Wednesday, September 15, 2010:

WindPower Innovations Inc., a wind power infrastructure and smart grid solutions company (PINK SHEETS:WPNV), announced talks with Alaska Villages Electric Co-op (AVEC), a non-profit electric utility, owned by the people served in 53 villages throughout interior and western Alaska, and is the largest service area of any retail electric cooperative in the world.

News of the talks arrived in a written statement from WindPower.

“We are in the second round of talks with AVEC to enhance the efficiency of their 250-500 kW wind turbines with our system optimization and grid-tie solutions,” says John Myers, president and CEO of WindPower Innovations. “Alaska represents a marketplace in the hundreds of millions and soon to be over a billion dollars for wind and other alternative energy sources, and the adaptability of WindPower Innovations’ technology allows us to capitalize on opportunities in extreme and remote environments where others can’t. We will be able to provide AVEC with solutions that help them break through barriers in efficiency and help solve the challenges faced by Alaska’s extremes in climate, geography and distance.”

AVEC is in the process of upgrading and increasing the operating efficiency of its power plant facilities and distribution lines, along with expanding its wind power segment, continuing to move away from costly diesel-generated power.

Continue reading: Wind power company in ‘talks’ with AVEC

Parnell signals support for large-scale hydro option

From The Fairbanks Daily News-Miner, Saturday, September 11, 2010:

Gov. Sean Parnell says that if Alaska is to meet the ambitious goal of getting half of its electricity from renewable sources some day, it will have to make a major commitment to big hydroelectric project, such as the Susitna project.

On a visit to Fairbanks today with running mate Mead Treadwell, Parnell said that he is putting a group together to see how a major hydro project could be financed. He said he wants to send a “strong signal” of his support of hydro power as a long-range option.

He also is looking for answers on ways to reduce the cost.

The Legislature and the governor approved $10 million earlier this year to update studies on Susitna and the proposed Chakachamna project.

The state now has an official policy that it will be getting 50 percent of its power from renewable sources by 2025, according to a law approved by the Legislature and governor earlier this year.

It may be impossible to reach that target in 15 years. It will be impossible unless decisions are made soon to get something underway.

Clean energy can lessen Native suffering

From The Anchorage Daily News, Sunday, August 15, 2010:

As an Alaska Native veteran, I want to see our country expand our clean energy sources. It will help our planet and our state, it will help Alaska’s Native peoples and it will help our national defense.

I am 69 years old. In my lifetime I have seen many changes connected to global warming. A big part of where I grew up has permafrost. The small village where my mother was born has sunk in and is now part of a large lake. I saw the old village of Kasigluk begin sinking in my short lifetime. The island where my maternal grandparents lived is mostly gone. A new Kasigluk was created almost a mile downriver from the old village. A new school, federally funded houses, post office and airport had to be built at a high cost.

The warming has affected the fall white fish runs on the Johnson River not far from Bethel. People there rarely fish for them anymore. The black fish creeks are almost nonexistent because of the changing river channels due to warming. The Yukon-Kuskokwim Delta has been invaded by beaver, which dam up the many small tundra creeks, disrupting the black fish runs.

Newtok, where my maternal grandmother’s family is from, and the village of Shishmaref need to be relocated at great cost due to erosion. Our elders link the erosion to changing weather due to warming. The melting of the permafrost also increases the cost of constructing homes and public buildings.

In rural villages, the cost of fuel to heat homes is high. So is the cost of electricity, which comes from expensive diesel fuel.

Continue reading: Clean energy can lessen Native suffering

Finding energy at the ballot box

From The Tundra Drums, Friday, August 20, 2010:

If Alaskans aren’t at a crossroads politically, we’re drawing close. Most all candidates running for statewide offices this year have given due time to talk about the state’s energy future, since we’ve been living off of our energy past for so long and change is coming. A dwindling flow of oil down the pipeline makes it impossible to ignore. It’s the way the state pays for much of what it does, so it impacts nearly everyone. Two of the five questions posed to candidates by Alaska Newspapers Inc. deal directly with energy and how we acquire it.

We also asked them about other issues important to rural Alaskans: subsistence, fisheries, jobs. Every candidate running for the U.S. House, U.S. Senate, governor’s office and lieutenant governor’s office was sent the same questions. Below are answers from those who responded.

Continue reading: Finding energy at the ballot box