MADISON — Dane County plans to stop making electricity with natural gas extracted from heaps of garbage and manure so that it can sell the gas through an interstate pipeline for use as environmentally-friendly automobile fuel.
The $23.5 million project at the county landfill would be the first of its kind in the state.
The effort is a response to utility company plans for sharply cutting back on the money they have paid for nearly a decade to dozens of landfills and waste digesters for gas-generated electricity.
Multi-year contracts with utilities provided more short-term certainty about revenue levels than the county and others will have selling the gas at market prices.
But Dane County officials say current natural gas prices and government subsidies are very likely to mean more income as soon as new equipment is up and running early in 2019. And without the limits imposed by the utility contacts, the door will open to greater production of renewable energy that does far less environmental damage than fossil fuel.
The landfill will gradually increase its gas production and the county hopes the switch to gas sales will lure more private investment to build more biodigesters, said county executive Joe Parisi.
“Our digesters are so important to our lakes cleanup effort,” Parisi said. “This not only shores up the economic stability of our existing digesters, but potentially allows us to expand the number of digesters throughout the watershed.”
Dane County’s sprawling landfill on Highway 12/18 is one of several in the state that collect gas that is created by the breakdown of organic material. Biodigesters collect manure and food waste to produce the gas.
The county projects sales of gas from the landfill alone to bring in millions of dollars annually. And biodigesters that truck their gas to the county’s injection point in an interstate pipeline will bolster their bottom lines, Parisi said.
Technological advances and government subsidies have made selling the gas more lucrative in recent years. The federal subsidies are folded into the ethanol program, which appears to have the backing of the Trump administration, Parisi said. The state of California also offers subsidies the county will pursue.
Three years of gas sales revenue will cover the $18 million cost of equipment needed to purify and inject gas into the TransCanada pipeline that happens to run under the landfill, said county solid waste manager John Welch.
In addition to the $18 million in the current county budget, Parisi has proposed another $5.5 million for equipment to inject gas trucked in by biodigesters. One has committed and another has expressed serious interest in the fee-based service, Welch said. Parisi has also proposed $250,000 to study where new digesters should be built.
More than a decade ago the state Legislature and Democratic Gov. Jim Doyle instructed the Public Service Commission to encourage more production of renewable energy. The state’s investor-owned utilities agreed to pay more than the market rate for a limited amount of gas-generated electricity to help spur construction of digesters and encourage capture of landfill gas.
Dane County’s landfill cleared about $2.7 million annually selling electricity to Madison Gas & Electric. But when its contract lapses in 2019, that would drop to about $500,000, Welch said.
For the Clean Fuel Partners biodigester near Waunakee, it had been unclear how operations could continue after 2020 when its contract with Alliant Energy expires and revenue drops, said Clean Fuel Partners president and chief executive officer John Haeckel.
On Wednesday, Haeckel joined a group that met with the county’s natural gas consultant. Haeckel said if his initial calculations on gas sales hold up, he hopes to purchase gas purification and compression equipment as soon as the county is ready to begin accepting gas. And he wants to increase gas production by 50 percent by activating an idle 1.25-million-gallon digester if he can find farmers to supply more manure, obtain regulatory approvals and secure a market for by-products.
The U.S. Environmental Protection Agency requires landfills to control emissions of greenhouse gases that leak from decomposing refuse. Some simply collect and burn it off into the air, but others, like Dane County, have fed it into electrical generators.
Generating electricity with gas from landfills or biodigesters also reduces carbon emissions by reducing the need for energy from coal-fired energy plants.