Methane from animal waste powering renewable natural gas programs

In this March 31, 2017, file photo, dairy cattle feed at a farm near Vado, N.M. Virginia-based Dominion Energy and Vanguard Renewables Ag of Massachusetts announced in January a $200 million partnership to convert methane from cow manure into renewable natural gas. The money will fund projects at dairy farms in New Mexico, Colorado, Utah, Nevada and Georgia. 

Inexhaustible sources of methane such as hog and cow manure and food waste from restaurants are powering a growing renewable natural gas industry, and Utah consumers now have an opportunity to boost that effort.

Dominion Energy customers can elect to buy blocks of renewable natural gas at $5 each, added as a surcharge to their monthly gas bills. Dominion uses funds from this GreenTherm program to purchase renewable natural gas from methane recapture plants, either in Utah or around the country.

“Theoretically, if we’re able to replace 4% or 5% of the natural gas on our system with methane derived from waste, that’s a lot of gas and our system would be carbon neutral,” Dominion spokesman Don Porter said. “It’s a pretty big impact.”

In addition to reducing use of fossil-based natural gas, diverting the various sources of waste for renewable gas processing cuts the release of large amounts of methane into the atmosphere, thereby limiting greenhouse gases.

“Our goal is to buy renewable gas locally if it’s available,” Porter said. “If we can’t, we need to go find it somewhere else.”

The more customers who choose to buy renewable energy blocks, the more Dominion will be able to expand the use of renewable gas, he said.

At least two significant methane recapture programs are in operation in Utah, although only one of them has a direct connection to Dominion.

In a $500 million venture with Smithfield Foods, Dominion will capture methane from Smithfield’s hog farms and convert it into renewable gas for use on the Dominion system.

The companies hope the venture will produce enough renewable gas to power more than 70,000 homes by 2029. According to a news release, the program’s first project, in Milford, began operation in 2019 and will power 3,000 homes and businesses when it reaches capacity.

In an unrelated project in North Salt Lake, the Wasatch Resource Recovery plant will convert organic waste, much of it from restaurants. The refined gas — enough to serve 40,000 people — will be fed into the nearby natural gas pipeline, according to Wasatch.

Wasatch Resource Recovery

This undated photo shows the Wasatch Resource Recovery plant in North Salt Lake. The plant refines organic waste, much of it food from restaurants, into renewable natural gas.

“More of these things are being built all the time,” Porter said. “We’re doing this (GreenTherm blocks) so people who want to reduce their carbon footprint will be able to basically buy into this.”

A Dominion fact sheet says one $5 GreenTherm block is equal to half a standard dekatherm of renewable natural gas. A typical Utah residential customer uses 80 dekatherms of natural gas annually.

“Hog waste and dairy waste, that stuff is pretty potent methane,” Porter said. “If it just escapes into the air like it’s doing at these farms, it’s 25 times more potent than if you were able to capture that gas and burn it another way.”

The Environmental Protection Agency says replacing diesel or gasoline with renewable natural gas can significantly reduce emissions of nitrogen oxides and particulate matter, improving air quality.

Dr. Scott Williams, executive director of the Healthy Environment Alliance of Utah, said his group has not deeply studied methane recapture projects, “but we would need to be sure they didn’t generate carbon emissions from the processing.”

Such projects also should be “cost effective for the ratepayer as alternative sources of energy,” he said.

Concerning any other environmental damage or degradation of wildlife habitat that may result, Williams said, “we’re sympathetic to those issues as well.”

Participation in Dominion’s GreenTherm program is voluntary. Customers who do not participate will not pay more for natural gas service, the company said in a news release.

Customers can enroll by logging in at DominionEnergy.com or calling 877-250-0037. More information can be found at DominionEnergy.com/GreenTherm.

You can reach reporter Mark Shenefelt at mshenefelt@standard.net or 801 625-4224. Follow him on Twitter at @mshenefelt.

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