Energy Conservation and Geothermal Energy: A Multidisciplinary Program of Research, Education and Demonstration
Additional Information
Commercial
Case Studies/Projects
Geothermal Energy
Energy Resource Station
NBCIP
Lighting Research Center
Grant #: 95-03
Principal Investigator: Charles E. Atchley
Organization: Northeast Iowa Community College
Other Participants: Interstate Power Company, Iowa Heat Pump Association, Hawkeye
Tri-County Electric Cooperative
Student Support: Student participation from Industrial Electrician, Electronic Technology, Commercial/Residential Electrician, Computer Technology, Heating, Ventilation, and Air Conditioning (HVAC), Computer-Aided Design and Marketing programs.
Project Dates: 7/1/95 - 12/31/96
Technical Area: Efficiency
Background and Significance:
Background and Significance Geothermal ground-source energy systems are increasing in importance as viable alternatives to heating and cooling by conventional gas, oil and electric systems. These systems contain electrically- powered heat pumps that concentrate and move heat from the nearly-constant temperature of the subterranean Earth to provide heating, cooling, and hot water to residential and commercial buildings. In a closed-loop system, water or an antifreeze solution is circulated through plastic pipes buried in either vertical or horizontal loops beneath the Earth’s surface. During the winter, the fluid collects heat from the Earth and transports it through the pipe loops into the building for heating. During the summer, the fluid cools the building by pulling heat from the building and transporting it through the system into the ground, which is at a cooler temperature. This process creates free hot water in the summer.
The utilization of geothermal energy systems for heating and cooling benefits the consumer, utility company, and the environment. Consumers receive lower operating and maintenance costs, a higher operating efficiency, an outstanding system reliability and lifetime, substantial noise reduction and safety, and improved indoor air quality and comfort. Utilities benefit by an increased market share, reduced electrical demand, and improved load factor during summer. Last, but not least, the environment benefits by lower carbon dioxide emission and less acid rain.
The Geothermal Heat Pump Consortium, Inc. (GHPC) is a national organization dedicated to the creation of a large, competitive, self- sustaining market for geothermal heating and cooling systems in both residential and commercial markets." Their primary mission is to increase annual installations of geothermal heating and cooling systems from less than 1% to around 10% of the heating/cooling market by 2001.
Project Objectives:
NICC has focused on three objectives included in GHPC’s mission:
provide opportunities for geothermal training for HVAC workers, utility employees, and contractors; increase research on the efficiency of geothermal energy systems in the Midwest; and disseminate quality information on geothermal energy systems.
Northeast Iowa Community College has utilized the grant from the Iowa Energy Center (IEC), funding and technical assistance from Interstate Power Company, funding from Hawkeye Tri- County Electric Cooperative, and organizational assistance from the Iowa Heat Pump Association (IHPA) to address these mission objectives in their collaborative project.
Training
In cooperation with IHPA, NICC developed and offered a Heat Pump Contractor Training Series. This series of twelve courses provided up-to-date information to HVAC workers, utility employees, engineers, and contractors on marketing, installing, and maintaining geothermal energy systems. They were delivered to eight different sites around Iowa using the fiber optics Iowa Communications Network (ICN). In addition, one vertical ground-source loop, one horizontal loop, and two heat pumps were installed in the HVAC laboratory at NICC. These loops are used by faculty to train students on the proper operation and maintenance of geothermal energy systems in conjunction with the grant project described below.
Research
The IEC grant and donations from Interstate Power Company (IPC) were used to purchase and install seven CR10 monitoring devices with accompanying software in the Presbyterian Church in Postville, Iowa. These units monitor 16 geothermal ground-source heat pumps and four- vertical ground loops, receiving and storing data collected from an array of soil, temperature, humidity, wind, and flow sensors. The collected data is accessed through a modem by computers at the NICC campus. An EXCEL-5 computer program is used to actively organize, analyze, and display the resultant data. NICC students and faculty worked with technical representatives from IPC to install and troubleshoot the entire electronic system for the CR10 monitors and sensors.
An analysis of data collected to December 17, 1996 yields the following conclusions:
1. Demand for electrical energy to heat and cool the entire church is dramatically less for the geothermal energy system than for heating only by the conventional boiler system that previously existed in the church.
2. The yearly cost of heating and cooling the church with the geothermal energy system is approximately the same as heating the church with the conventional boiler system, since the price of natural gas is currently much less than that of electricity. Thus, for the same yearly energy cost, the church can now be cooled in the summer, so that the comfort level for the occupants of the church has been increased at no additional cost.
3. During the warmer summer months, no correlation was observed between cooling degree-days and the energy consumed by the geothermal system.
4. Greater room insulation was strongly correlated with decreased energy consumption.
5. The temperature fluctuations within a church room were greater for rooms with lesser amounts of insulation and greater exposure of the room walls to the outside. Church thermostats were set at a constant. Air temperatures for rooms with more insulation and less exposure to the outside varied between 70o F to 73° F Two rooms that have more outside exposure and less insulation exhibited a temperature variation between 65° F and 78° F
6. A linear relationship exists between energy consumption (in kWh/day) and heating degree- days (base = 65° F). Around 11.4 kWh of electrical energy was used each day by the geothermal system for every degree the daily average outdoor air temperature fell below 65° F
Dissemination
Preliminary results from the Postville Church Geothermal Project as well as general information on geothermal ground-source energy systems were presented at a two-day symposium held at the NICC campus on May 14-15, 1996. NICC students in advertising and marketing programs designed brochures, scheduled speakers, arranged for travel and lodging accommodations for symposium speakers and participants, and organized a marketing campaign to promote the symposium. Symposium topics included basic earth loop design software tools, marketing of geothermal systems, and specific performance and installation information for residential and commercial structures. Tours of local geothermal energy installations, including the Postville Church, were also conducted.
Monitoring equipment and computers purchased with IEC grant funds and donated by Interstate Power Company will remain in activation after the expiration of the grant. Research will continue on the interplay between electrical energy consumption and environmental variables, such as wind speed and direction, heating degree days, insulation levels, indoor air temperature and humidity, heat pump operating conditions, and ground loop flow rate. This project will continue to produce data and results that will be forwarded to IEC and IPC for use by others.
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