Prince of Wales residents were invited to attend an Air Source Heat Pump Expo on this spring at the Craig High School. The Expo featured guest speaker Dana Fischer from Efficiency Maine, and included mechanical contractors, financial institutions, and experts statewide through a webinar.
The event was organized because the micro-grid that supplies POW residents with electricity will soon have more hydro power electricity on-line, than the island currently demands. Today most of POW residents use diesel oil to heat buildings; the new hydro plant may provide a unique opportunity for residents to convert to a more efficient and sustainable heating option.
What are Air Source Heat Pumps? Air source heat pumps (ASHP) use electricity to circulate air through a heat pump, this is the same technology used in your refrigerator, but in reverse. The heat pump extracts heat from the air outside and transfers it into the building. Even in cold climates, outdoor air contains heat. The efficiency of a heat pump will change with the temperature outside. High performance ASHP models have been shown to perform at, and below, 00F.
In southeast Alaska’s mild climate, heat pumps can have a coefficient of efficiency (COE) that surpasses other heating technologies. For example, a COE of 2 means that for every one unit of energy which goes into the heat pump system, two units of energy are produced. It is typical for a heat pump unit to deliver four units of heat for every unit of electricity at 50°F, but only deliver two units of heat for every unit of electricity at a temperature of zero. However, a COE of two is still much better than the COE for heating fuel (COE of 0.85), or electric space heaters (COE of 1), neither of which change depending on temperature.
Electric Rates and Conversion to an ASHP: Hiilangaay Hydropower is expected to come online in 2018. The 5-megawatt hydropower project near Hydaburg will eliminate the need for diesel powered electric generation (except during times of maintenance), and result in a surplus of clean energy available for future growth on the island. Growth in electric demand will actually result in utility fixed costs being spread over a larger sales base, resulting in downward pressure on rates.
Prince of Wales residential customers currently pay $0.25 per kWh, $0.23 per kWh with Power Cost Equalization (PCE). Heat pump use and the related cost will vary by household circumstances. AP&T strongly encourages customers to do their own research and analysis based on the cost of heating fuel, electricity, heating habits, and the age/ efficiency of the old heating system.
It can be challenging for consumers to predict the cost comparison over time, because today’s fuel and electric prices are unlikely to be the same as tomorrows. One advantage offered by ASHPs on Prince of Wales Island is that they provide more stable, predictable pricing due to the fact that they use locally available hydropower. The price of hydropower is relatively flat, and is not susceptible to global events which impact the supply and price of oil.
Homeowners are encouraged to maintain a back up heat system for very cold temperatures. This allows consumers to use fuel if diesel prices temporarily fall, allowing residents to take advantage of temporary price swings. Some consumers also choose to keep wood stoves or propane heaters as supplemental heat sources.
The Cold Climate Housing Research Center has done a lot of research on the effectiveness of ASHP’s in Alaska, and specifically in SE Alaska. For more information, including contact information for mechanical installers and financial institutions, visit AP&T. To request an Air Source Heat Pump financial calculator, email firstname.lastname@example.org.