The next source of clean fuel for Oregon homes may be the food you eat — or at least what’s left of it once you’ve digested it.
Lane County will start building facilities next year to capture and treat methane from wastewater, turning it into a renewable natural gas product. A new state law allows utilities to use it as an energy source despite it being a higher-cost resource.
The law, which Gov. Kate Brown signed at the end of July and takes effect Sunday, clears the way for natural gas distributors to use renewable natural gas in existing systems. Oregon public utilities are required to deliver service as cheaply as possible, a longtime barrier for using renewable natural gas.
Using renewable natural gas from waste products is more expensive than using fracked natural gas but is cleaner, according to the resource’s proponents.
Renewable natural gas is, essentially, methane harvested from rotting food, livestock waste, wastewater and other sources. That gas then can be injected into current natural gas infrastructure and used to power homes, reducing the reliance on fossil fuel natural gas.
The Metropolitan Wastewater Management Commission, a Eugene, Springfield and Lane County partnership, may begin adding renewable natural gas to that distributor’s system by 2021 following the construction of a facility that will harvest methane from wastewater.
“We generate it locally,” said Springfield Managing Civil Engineer Josh Newman.
The renewable natural gas then can be sold, to NW Natural and to companies that can process it into vehicle fuel.
Biogas from wastewater has been part of the local electricity grid since the 1980s, Newman said, but the technology now exists to further refine it into renewable natural gas, which is essentially the same as natural gas obtained from fracking and used in NW Natural pipes.
By building an estimated $10 million facility at the Eugene-Springfield waste water plant, Newman said the plant will be able to generate and then sell renewable natural gas. That plan already was in the works before the new law passed this year and the original intention was to sell the gas for transportation fuel, but Newman said allowing utilities to use the gas will add another customer.
“Up until recently we’ve just been focused on producing clean water, but this comes in as a resource. So how can we best utilize this resource?” said Newman.
Depending on how it’s produced, the report said renewable natural gas could equate to between 4.6% and 17.5% of Oregon’s total yearly use of natural gas. U.S. wastewater treatment plants could meet 12% of the national electricity demand, according to the National Association of Clean Water Agencies.
The law includes regulations to limit the price hike customers would experience from a more expensive resource being used in energy supply.