The U.S. Coast Guard Research & Development Center wanted to demonstrate that fuel cells are capable of providing power to operational units during power outages caused by adverse weather conditions, such as ice storms or blizzards. The center chose to install a FuelCell Energy Model DFC 300 250-kilowatt natural gas fuel cell at Air Station Cape Cod, one of the largest U.S. Coast Guard air stations on the East Coast. In addition to electric power, the fuel cell provides heat for domestic hot water for the Bachelor's Quarters and an associated galley and, at full 250-kilowatt design output, has the potential to provide space heating for the entire building.
In its first 12 months of operation, the fuel cell averaged an operating availability of 96.2 percent above its first year's expected design availability, producing a total of 1,392 megawatt-hours of electricity; 1,250 megawatt-hours of total production powered the entire Air Station Cape Cod building loads, while the remaining142 megawatt-hours powered the internal fuel cell loads. Over the same year, approximately 1,832 MMBtu of recovered heat was utilized for domestic hot water use, offsetting the purchase of nearly 26.3 million cubic feet of natural gas and resulting in a total net savings of almost $24,000 in operating expenses.
Demonstrating one of the main benefits of fuel cell technology, in 2003 the fuel cell at Air Station Cape Cod provided emergency power to the barracks and galley during a number of short grid outages, and in September 2003 was operated in a totally grid-independent mode as a precaution against a potential loss of commercial power during a hurricane. Although Cape Cod was not affected by the widespread blackout of the Northeast in August 2003, the fuel cell is poised to demonstrate its value in case of a major utility outage.
One important lesson learned from this demonstration is that site loads should be accurately determined prior to the design of a fuel cell project. Originally, the site expected to use the total fuel cell output, which provided cost savings by avoiding additional utility interconnection requirements. After installation, it was discovered that the fuel cell output exceeded site demand, resulting in part-load operation between 150 and 180 kilowatts. Had the loads been determined more accurately, additional buildings could have been connected to the fuel cell or provisions made to export power.
Because fuel cell economics are dependant on both electricity and gas prices, rising natural gas prices also had a negative impact on expected cost savings. If gas prices should continue to rise, it may become more economical to purchase electricity rather than generating it. Maintenance is another important factor to consider prior to procurement of a fuel cell, as restacking and preventative maintenance costs can be significant. While the first year's maintenance was included in the original procurement for this fuel cell, current negotiations will determine the long-term maintenance costs and ultimately the fuel cell's future.
Air Station Cape Cod intends to operate the fuel cell as long as the economics are favorable. Funding was obtained for the design and installation of the utility interconnection needed to allow the fuel cell to operate at full power, and Coast Guard personnel are also working to reach agreement with their utility on export of excess energy. Finally, the economics of the long-term operation and maintenance costs will significantly impact cost-effectiveness.
In recognition of its superior performance and management, the Air Station Cape Cod fuel cell project was selected as one of only two winners in a new Energy Security & Reliability category of the 2004 Federal Energy and Water Management Awards.
For more information about this project, contact Shawn Herrera, FEMP, firstname.lastname@example.org, Mark Halverson, PNNL, email@example.com, or Bill Chvala, PNNL, firstname.lastname@example.org. To monitor continuing operation of the Air Station Cape Cod fuel cell project, including meter readings, status reports, outages, and availability, visit: http://www.uscg.mil/systems/gse/energy/technology/technology.htm#AIRSTA%20Cape%20Cod%20Fuel%20Cell%20Project.
Reprinted from FEMP Focus, a publication of the U.S. Department of Energy, Office of Federal Energy Management Programs. For more information, visit www.eere.energy.gov/femp/.
Publication date: 10/17/2005