Southern California Gas Co. (SoCalGas) and biogas producer Calgren Dairy Fuels announced that renewable natural gas produced at Calgren’s dairy digester facility in Pixley, California is being injected into SoCalGas pipelines. The project marks the first time that carbon-negative renewable natural gas produced from cow manure has been injected directly into SoCalGas’ natural gas system.

In August 2018, SoCalGas began receiving renewable natural gas into its system from CR&R, Inc.’s  anaerobic digestion facility in Perris, California. The renewable natural gas from that digestion facility is already being used to fuel about 400 waste hauling trucks. Renewable natural gas is a carbon-negative fuel produced from waste and agriculture that can be used in trucks and buses, to generate electricity, fuel heating systems in homes and businesses, and for cooking.

Developing renewable natural gas is a smart and cost-effective solution to reducing greenhouse gas emissions from the transportation and building sectors. Replacing just 16 to 20 percent of our traditional natural gas with renewable natural gas would reduce emissions equal to electrifying 100 percent of buildings in the state, but it would be two to three times more cost-effective. Moreover, the renewable natural gas solution does not require expensive appliance changeouts or costly new mandates.

—Sharon Tomkins, SoCalGas vice president for customer solutions and strategy

Calgren’s facility, known as a dairy digester pipeline cluster, will collect biogas from anaerobic digesters at 12 Tulare County dairies then clean it to produce pipeline-quality renewable natural gas. This is the first such dairy digester pipeline cluster in California and is expected to be the largest dairy biogas operation in the US when Calgren adds 9 additional dairies later this year.

The facility will capture the methane produced from the manure of more than 75,000 cows, preventing about 130,000 tons of greenhouse gas from entering the atmosphere each year, the equivalent of taking more than 25,000 passenger cars off the road for a year.

SoCalGas will be capable of adding up to 2.26 billion cubic feet of renewable natural gas each year to its pipeline system from the facility, enough to fuel more than 1,200 Class 8 heavy duty trucks.

Renewable natural gas can be produced from dairy manure, food waste, landfills, and wastewater treatment plants and other sources. Capturing this otherwise wasted gas and turning it into a renewable fuel significantly reduces greenhouse gas emissions from these waste sources.

A renewable natural gas solution to reducing emissions from the transportation and building sectors is also consistent with the mandate under Senate Bill 1383 to reduce short-lived climate pollutants, 80 percent of which comes from waste streams, dairies and agriculture.

Today, there are already 24 California dairy methane capture projects either operating or in development, and experts estimate there could be as many as 120 projects funded and operating in next five years. In addition, as the state seeks to divert organic waste from landfills and capture emissions from wastewater treatment plants, more renewable natural gas will become available.

The Calgren project and others like it are partly funded under California’s Dairy Digester Research and Development Program, which aims to reduce greenhouse gas emissions from manure generated at state dairy farms.  Calgren’s preference is to provide renewable fuel for existing CNG refuelers in California via SoCalGas’ pipeline system. However, the Calgren facility is also able to use the renewable gas to indirectly produce a high-octane gasoline additive or in a new biodiesel plant that will come online midyear.