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.
Representation of systems disturbed by wide band noise
In this paper, a method of handling and working with wide band noise is developed. We represent wide band noise as a distributed delay of white noise and use it to reduce a nonlinear system disturbed by wide band noise to a nonlinear system disturbed by white noise. An application of this reduction to a nonlinear filtering problem under a wide band noise disturbance is discussed.