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Air Force base cuts costs with methane generation

The patriotic neighbor who flies an American flag or sports a yellow ribbon bumper sticker has nothing on the Davis County, Utah, landfill that supports our military with 1.2 MW of clean, renewable energy.

Hill Air Force Base near Salt Lake City is the first Federal facility with its own dedicated landfill-gas powerplant. Located less than two miles from the small landfill, the base is the perfect end-user for methane-generated energy. “They were just flaring the gas before Wasatch approached us last year with the idea of using it for power,” said Base Utility Manager David Abbott.

Wasatch Integrated Waste Management District owns the landfill. “The base buys steam from Wasatch’s waste-to-energy facility, so we already had a relationship with the company,” Abbott noted.

Benefits move agencies to quick action
A self-generation project with a renewable resource component held several potential benefits for Hill. Like all Federal facilities, the base must comply with Executive Order 13123 to reduce its energy consumption by 30 percent by 2005. The projected output of the plant would supply a little over 3 percent of the base’s electricity needs, independent of grid events and rising energy prices.

Also, the facility could help Hill minimize the impact of time-of-use charges levied by its power provider Utah Power. “When we factored in the cost of natural gas, the answer was ‘Heck, yes!’” said Abbott.

The Department of Energy agreed. Base energy officers presented the idea to DOE officials at a conference they attended shortly after their discussion with Wasatch. “They were interested enough to come up and meet with people from the county,” said Abbott.

The proximity of the base to the landfill convinced the DOE that a facility was viable, and the project moved forward. “I’ve never seen an Air Force base move this fast on a project,” Wasatch Executive Director Nathan Rich said in an interview with Distributed Energy, a journal covering on-site power issues.

Cost savings pay for energy projects
One thing that sped the project along was the Federal Energy Management Program’s Super Energy Savings Performance Contract. The streamlined procurement process allows Federal agencies to award energy-saving projects to a pre-approved list of contractors and realize the cost and energy savings immediately. Hill selected Ameresco to build the plant and operate it under a 20-year contract.

The $3 million project received the first Technology Specific Super ESPC for biomass and alternative methane fuels. The tech-specific Super ESPC finances energy-saving systems that are not yet readily available through routine procurement processes. Biomass and alternative methane fuel is the latest technology to be covered by this category, which includes geothermal heat pumps, photovoltaics and solar thermal concentrating systems.

FEMP created the Super ESPC so Federal energy and facility managers could improve their buildings and install new energy-saving equipment without an up-front investment. The savings from the project pays for the cost of installation.

Hill uses the power from the landfill-gas generator and receives a credit from Utah Power of $.04/kWh under Rate Schedule 37. “So we are paying Ameresco instead of the utility,” said Abbott. “It’s a great program because there is not a lot of O&M money around for projects like this.”

Economic, environmental rewards

Under Energy Engineer Lt. Timothy Hinko, construction on the plant began in April 2004 and immediately yielded a valuable fringe benefit. Although Ameresco handled most of the building, Hill utility personnel laid 1.5 miles of pipeline on the base. “We used it as a training opportunity, because they don’t often get the chance to do heavy construction,” observed Hinko.

Wasatch put the landfill gas compression and conditioning station on-line and laid about 3,000 feet of pipeline to the base's fence line. Although the base is initially accepting only 400 to 500 cfm, depending on the quality of the gas, the compressor unit is sized to handle 900 cfm/scfm. Oversizing the system will allow the landfill to send additional gas when it becomes available.

The new powerplant is located next to the electrical substation serving the base. It houses switchgear and two Caterpillar generators with a total capacity rating of 1320 kW. There is room to add a third generator.

Commissioned in January 2005, the landfill-gas plant is expected to save Hill an estimated $394,379 in annual energy costs. By replacing 1 MW of coal-generated electricity with green power, the plant reduces annual emissions by 5,000 tons of carbon dioxide, 4.8 tons of carbon monoxide, 19 tons of sulfur dioxide and 5.5 tons of nitrogen oxide.

Numbers like those—and the 2004 Industry Partner of the Year award Ameresco received from the EPA Landfill Methane Outreach Program—suggest that more landfills should be drafted into service. Ameresco is eyeing potential sites for landfill-gas-to-energy plants in California and Nevada. Federal agencies may one day look on landfills as a great ally in the fight for energy independence.