Highlights of the California GeoExchange Project
A two year project sponsored by the Pacific Gas & Electric Company, the California Energy Commission, and the National Geothermal Heat Pump Consortium was initiated in 1997 to increase public awareness, identify California-specific cost-effective technologies, and reduce market barriers for ground-coupled heat pumps. Major activities included demonstration projects, research and development of system and loop designs, and market evaluations. Four commercial projects, and seven single and multifamily residential projects consisting of 326 units, were initiated. Five of these sites were monitored for up to 16 months. Monitoring data were used to calibrate DOE-2 models, which were in turn used to develop performance data for technical evaluations and market studies. Technical evaluations were completed on sizing methods, flow optimization, loop design options, water heating options, hybrid systems, and loop irrigation. Vertical helix loop designs were developed, installed and tested. The project developed 600 pages of reports, including a business plan for GeoExchange in California, and a GeoExchange Handbook. Project recommendations were to distribute key project findings, continue R&D on near term technologies, continue support for R&D to reduce loop costs, and to expand DOE-2 modeling capabilities to accommodate a larger number of system design options.
Monitored ground source heat pump performance in northern California
Fourteen residential ground source heat pump installations in the greater Northern California area were monitored during the period of December 1996 to January 1998. Equipment power, capacity, and efficiency, and loop water temperatures and flow were recorded on a 15 minute basis. Monitoring results were used to calibrate the DOE2.1E hourly building simulation program ground loop model and DOE2.1E was then used to estimate energy savings and life cycle economics for various load, system, and installation configurations.
Geothermal heat pumps at Fort Polk: Early results
At Fort Polk, LA an entire city (4,003 military family housing units) is being converted to geothermal heat pumps (GHP) under a performance contract. At the same time other efficiency measures such as compact fluorescent lights (CFLs), low-flow water outlets, and attic insulation are being installed. If these contracts and this technology are to be used widely in US Department of Defense (DoD) facilities and other public buildings, better data from actual projects is the key. Being the first GHP project of this type and size, Fort Polk proved to be very challenging for all concerned. To get from RFP to start of construction took several years. This hard work by others created a once-in-a-lifetime opportunity to address many of the due diligence issues that delayed the Fort Polk project. So that future projects can move faster, an evaluation has been undertaken to address the following barriers: absence of a documented large-scale demonstration of GHP energy, demand, and maintenance savings (a barrier to acceptance by federal customers, performance contractors, and investors); newness of large-scale facility capital renewal procurements at federal facilities under energy savings performance contracts (ESPCs) or traditional appropriations (lack of case studies); and variability in current GHP design tools (increases risks and costs for federal customers, performance contractors, investors and designers). This paper presents early energy and demand savings results based on data collection through January 1996.