Renewable Natural Gas (RNG) is produced from organic materials like wood waste, food and agricultural waste, and even human waste. As these materials decompose, they produce methane. We can capture that methane and then condition it to pipeline quality.
Today, the most common method of making RNG is through anaerobic digestion. This process uses heat and microorganisms to break down organic material in an environment with no oxygen. Gases are released, captured and conditioned to pipeline quality.
Another way to produce RNG from biomass is through a process called gasification. High heat and pressure combine to extract gases out of materials such as wood waste.
Sources (or feedstocks) of RNG can include dairies, landfills, wastewater treatment plants, forest debris and other organic waste. These sources are renewable.
RNG is interchangeable with conventional natural gas. It’s produced locally from waste streams that would otherwise be emitting methane directly into the atmosphere. We can transform these waste streams into RNG and use our existing pipeline system to deliver this renewable energy to vehicles – and one day, to homes and businesses. In doing so, we close the loop on waste and provide up to an 80% carbon reduction benefit.
Check out NW Natural's Plans for RNG and Frequently Asked Questions.
In July 2019, Oregon Governor Kate Brown signed Senate Bill 98 into law. This groundbreaking legislation allows utilities like NW Natural to buy renewable natural gas for customers.
“This is the first piece of legislation of its kind in the nation and we couldn’t be more pleased to lead the way,” said NW Natural President and CEO David H. Anderson. “It’s an important step in supporting our region’s move to more renewable energy, closing the loop on waste and investing in homegrown solutions that address climate change.”
We plan to pursue RNG opportunities, beginning with wastewater treatment plants and food waste facilities. In the future, we’ll look for ways to incorporate RNG produced from landfills, food waste and dairy farms as well as the gasification of wood waste.
The Oregon Legislature passed a law in the 2017 session that will track the sources of RNG in Oregon and help this emerging industry sector develop.2
In its first inventory of technical potential, the Oregon Department of Energy estimates enough feedstock statewide to produce 50 billion cubic feet (BCF) of RNG. That’s equivalent to the amount of natural gas used by all Oregon residential customers today.
NW Natural partnered with the city of Portland to put renewable natural gas — converted from the city’s largest wastewater treatment plant — into our pipeline and then into vehicles. In March 2018, Commissioner Nick Fish and the Bureau of Environmental Services announced the opening of a natural gas fueling station at the City’s wastewater treatment plant. The station will offer a clean-air alternative to diesel for City vehicles operating at the plant in industrial North Portland.
RNG can be used in combination with or in place of conventional natural gas. It can fuel heavy-duty vehicles or be blended into our pipeline system to serve homes and businesses.
The Coalition for Renewable Natural Gas (RNG Coalition) serves as the public policy advocate and education platform for the Renewable Natural Gas industry in North America. The RNG Coalition advocates for increased development, deployment and utilization of renewable natural gas so that present and future generations will have access to this domestic, renewable, clean fuel and energy supply.