The Juneau Airport secured funding in October 2008 to install a ground-source heat system. The State of Alaska provided a grant for half of the cost of the project, with the City of Juneau paying for the rest. The system is designed and will be built by Alaska Energy Engineering LLC.
The system involves 215 vertical wells, each 175 feet deep with 0.75 inch high-density polyethylene piping. The heat pumps will supply both heat in the winter and cool air in the summer by using the ground-source heat in a reversible compressor/condenser cycle, with the primary product being winter heat. Alaska Energy Engineering estimates a 260% energy efficiency for the system.
Alaska Energy Engineering has calculated the capital cost of this project at $6.05 million with annual electric use of 656,000 kWh and annual O&M costs of $644,000. This project is being built instead of an alternative fuel oil system. The fuel oil system would have lower capital and annual O&M costs ($5.23 million and $268,000, respectively). The fuel oil system would use 40,825 gallons of fuel and 212,000 kWh of electricity annually. Assuming a fuel oil price of $3.31 and an electric price of 7.9¢ per kWh, the ground-source heat project is expected to save over $85,000 in annual energy costs. Note that the need for air conditioning is an important contributor to the economics of this project.
A similar project is proposed that will produce 4.1 billion BTUs annually to meet approximately 81% of heat load for a new pool in Juneau. It is expected to cost $2 million and to eliminate either 63,200 gallons of fuel oil or 1.5 million kWh annually. Annual O&M costs are estimated at $113,220.