At one point, the city’s energy-to-ice system was paying dividends.
Gas from the capped landfill was helping to power a cogeneration system at the Weibel Avenue ice rink and was helping to reduce energy costs. The system won the city an award in 1996 and was helping save an estimated $50,000 annually in operation expenses.
But the system began developing problems around 2003. About five years later, an energy consultant suggested high-efficiency chillers and other modern improvements would save more money than the faltering methane-fueled system.
The city took that advice — something that saved roughly $100,000 in 2009. The new efficient chillers, however, weren’t compatible with the German-engineered MWM 307-KW engine generator, so the once state-of-the-art system was quietly mothballed.
“They so drastically reduced the energy needs the Genset was no longer compatible with producing power,” said Fred Wehran of the New Jersey-based Wehran Energy Corporation. “That was something not thought of or anticipated before.”
Of course, the landfill is still producing methane. And instead of being burned for fuel, the potent greenhouse gas is being released into the atmosphere, albeit in relatively small amounts.
That small amount of methane is now posing two distinct issues for the city outside of its impact to the environment. First and foremost, the gas can build up into potentially dangerous concentrations, and it has shown signs of doing so while inching toward a now-populated area across from the city’s decommissioned landfill on the east side of Weibel Avenue.
But also, the city must dispose of the methane to be eligible to collect the 10 percent remainder of a grant from the state Department of Environmental Conservation in 2008. The city has received $534,000 from the agency so far, but needs to find a way to either use or otherwise burn the methane by the end of the year in order to close out the grant.
“This is a very critical time and we do need to take action,” Mayor Joanne Yepsen told the City Council during its meeting Tuesday.
The city’s landfill was capped in 1995 and was producing enough methane gas then to justify installing the cogeneration system for reducing the roughly $110,000 annual energy costs at the nearby ice rink. At the time of its installation, the system was a benefit to the city.
“It was an award-winning concept,” said Bill McTygue, the city’s former director of Public Works.
But landfills don’t produce an infinite amount of methane — the levels can drop off precipitously depending on the size of the landfill. The Spa City’s old landfill, for instance, is producing only 10 percent to 20 percent of the methane it was emitting after it was first capped 19 years ago.
“The [methane] production curve of landfill is a little bit like a ski slope,” Wehran said. “This one is in the flattening-out part of that production curve.”
The system to collect the methane also isn’t what it used to be. Now approaching two decades old, the blower system moving gas from the methane wells is reaching the end of its lifespan.
“What’s there is beat-up and is old,” Wehran said. “It’s been out there in the weather and needs to be replaced.”
The city also needs to decide what to do with the gas. The most simple option would be to create a flare that would constantly burn off the methane produced by the landfill.
The city could entertain other options, such as using the methane to heat a greenhouse or develop a system to convert it into compressed natural gas for use in vehicles. But none of these options are cheap and they don’t always have a financial payback in the end.
The city approved up to $60,000 for Wehran’s company to study the issue and produce a solution to burn off the methane, close out the DEC grant and upgrade any of the systems that need replacing. It’s unclear how much the process will ultimately cost, but it’s something that needs to be done in short order.
“We want to make sure our system is functioning properly,” city engineer Tim Wales said.