Landfill will supply power to CPS
February 05, 2013 | posted by The Institute
When CPS Energy customers turn on the lights next summer, part of the power could be coming from garbage.
An 18-month-old company plans to begin construction in March of a landfill-gas-to-electricity plant at the city-owned Nelson Gardens landfill on the Southwest Side.
Officials at Nelson Gardens Energy LLC say the plant, expected to be running in July, will have a capacity of 4.24 megawatts.
CPS has a 15-year agreement with Nelson Gardens Energy's affiliate, Greenfield Energy of Liverpool, N.Y., to buy the power. CPS spokeswoman Christine Patmon declined to say what the utility will pay for the power.
The plant's output “is not a lot in the grand scheme of things for CPS,” said Thomas Kennedy, a principal at Nelson Gardens Energy and Greenfield Energy. Yet it would contribute to CPS' renewable-energy portfolio.
Kennedy estimates that his company will sell about 33 million kilowatt-hours to CPS each year.
CPS has more than 728,000 electric customers, and average usage per customer is 1,100 kilowatt-hours a month, the utility said. That would equal demand of more than 801 million kilowatt-hours a month.
The electricity will be produced by processing the landfill's gases, including methane formed by decomposing waste. Methane is a greenhouse gas that's 21 times more harmful to the atmosphere than carbon dioxide, according to the Environmental Protection Agency.
Because landfill gas is a renewable resource, many utilities are including it in their generation portfolios.
“It's a small but steady renewable resource,” Patmon said. “If it wasn't captured, it would go unused. And we try to use or recycle everything we possibly can. So, why not use landfill gas to power homes and businesses?”
Nelson Gardens Energy plans to finance the $9.5 million project with bonds issued by the Mission Economic Development Corp. in the Rio Grande Valley.
The City Council recently approved Mission's plan to issue taxable revenue bonds to finance the project. Mission sought — and received — permission from the council to finance the plant because it will be built within the city's jurisdiction, said Ed Davis, the city's assistant director of economic development.
Mission officials did not respond to requests for comment.
Mission Economic Development Corp. has issued $250 million in bonds for pollution control projects in about 25 counties in Texas, said Lee McCormick, president of Community Development Associates LLC, which acts as a financial adviser to Mission.
San Antonio has no liability for the bonds to be issued, Davis said, and will gain at least $12,000 a year from a lease for the land.
Nelson Gardens Energy will be responsible for maintaining the landfill's gas collection system, which includes 139 vertical wells and three gas collection trenches. But it will lease just one acre from the city.
“That's big enough for our plant,” Kennedy said. Much of the equipment for the plant is now onsite, he said. The company will hire four employees locally for the facility.
At present, the landfill methane is flared, or burned off, by the city's Solid Waste Management Department.
“Instead of flaring, we're going to take the gas to our plant, clean it up, compress it and use it as fuel for the four engines that will drive four generators to make electricity,” Kennedy said.
The gas from Nelson Gardens “is pretty good,” he added. “We've been testing it, and it doesn't have some of the typical contaminants.”
CPS also has a contract to buy electricity from Energy Development Inc., which produces electricity from landfill gas at Waste Management Inc.'s Covel Gardens landfill. It's adjacent to Nelson Gardens.
Energy Development's plant has a capacity of 9.6 megawatts. That amounts to about 5,000 megawatt-hours of power it can produce each month, CPS' Patmon said.
“It's a pretty steady source of generation,” she said, “and comes in 24-7.”