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The Role of Renewable Natural Gas in the Decarbonization of Our Economy

The potential of renewable natural gas in the decarbonization landscape is examined in this Q&A with Johannes Escudero, CEO and Executive Director of the Coalition for Renewable Natural Gas (RNG Coalition).

Decarbonization — a phased reduction of carbon dioxide emissions by eliminating or significantly reducing the use of fossil fuels — is a key piece in the climate-change mitigation puzzle. The combination of decarbonization and electrification can result in an enormous reduction of greenhouse gas emissions, not to mention energy savings. Electricity generation using renewable natural gas (RNG) increases the decarbonization benefit even further.

I recently met with Johannes Escudero — CEO and Executive Director of the Coalition for Renewable Natural Gas (RNG Coalition) — to discuss the environmental challenges we face and the solutions we can employ, including renewable energy sources. The RNG Coalition is the trade association representing and providing public policy advocacy and education for the North American RNG industry.

John Hanselman: What role does renewable natural gas play in the implementation of decarbonization strategies?

Johannes Escudero: When working toward a resilient energy system and economy, RNG — like electrification — is an important piece of the puzzle. Our world needs a diverse portfolio of sustainable solutions — including decarbonization — to truly address global environmental challenges. We cannot afford to place all bets on a single stock or gamble with our future by placing all chips on one approach. Renewable natural gas is a necessary and complementary resource that pairs well with other decarbonization technologies.

JH: How is renewable natural gas produced?

JE: RNG production starts with the collection and control of naturally occurring biogas — including methane — that emits from the anaerobic digestion of organic feedstocks, such as food and beverage waste and farm manure. Biogas is upgraded to RNG by removing CO~2~ and trace contaminants to create a purified gaseous product — biomethane or renewable natural gas — that is completely interchangeable with traditional natural gas.

JH: Is there enough RNG available to contribute to an impactful decarbonization strategy?

JE: Sufficient RNG could be developed from organic waste feedstocks to cover approximately 13 percent of current US natural gas demand. This could be used to supply all current commercial gas demand nationwide, 75 percent of current residential demand, or 45 percent of industrial demand.

JH: How does renewable natural gas work with other decarbonization strategies, such as electrification?

JE: The RNG industry alone cannot solve the challenge of decarbonizing existing natural gas and oil demand — but RNG is an important and sustainable part of the solution. As of January 1, 2021, we have 157 operational RNG production facilities in North America, and an additional 110 RNG production facilities under construction or that have completed substantial development.

According to the International Energy Agency, there are limits to how quickly and extensively electrification can occur; because electricity is not well suited to deliver all types of energy. Even California — which is in the top tier in energy consumption and on an aggressive path to net-zero energy consumption — will still require significant volumes of gas in 2050. Per the California Energy Commission, in a high-electrification scenario, just under 1,000 tBtu of gas demand will still exist in California in 2050 — compared to approximately 2,000 tBtu in 2020.

In the longer run, we expect other sources of renewable gas — including hydrogen derived from RNG and from renewable electricity — to play an important role in meeting energy demand that can’t easily be electrified. Renewable hydrogen is currently more expensive than RNG derived from organic wastes.

Vanguard Renewables' Farm Powered anaerobic digestion facility; Haverhill, MA | Image credit: Vanguard Renewables

JH: Will renewable natural gas programs incentivize the generation of more waste?

JE: Absolutely not; but so long as life on our planet is sustained and energized by organic materials, there will always and inevitably be some waste. Every day, society pushes waste bins out to the curb without giving thought to what happens next — including with the organic waste we produce. What happens to that waste matters. Unless RNG production facilities are developed, that methane will be flared (literally wasted) or worse, escape fugitively into the atmosphere as a short-lived climate pollutant and greenhouse gas that is many times more harmful than CO~2~. RNG production facilities abate and recycle captured methane and convert those avoided emissions into renewable energy for productive, everyday applications.

JH: Is renewable natural gas too expensive to be a meaningful part of decarbonization?

JE: As with all renewables, there is also a premium associated with RNG production — but as markets mature and technologies advance the cost delta between RNG and conventional natural gas is decreasing. RNG supply from organic waste is comparable in price with other important decarbonization technologies. Further, GHG emissions reductions from RNG often fall below regulated cost-containment caps in those places in the US where the pricing target is set by utilities. RNG is an available drop-in substitute for conventional natural gas.

JH: Will increased use of renewable natural gas require a buildout of infrastructure?

JE: No. RNG production facilities are co-located with various sources of organic waste — including at landfills, wastewater treatments facilities and farms, and connect to existing gas systems. As such, interconnecting with RNG production facilities presents an opportunity for gas utilities to decarbonize existing energy infrastructure and offer their customers a renewable product. RNG is transported via virtual (mobile) pipelines and gas distribution to the end-user for transportation, dispensation and consumption. Because of RNG’s compatibility with conventional gas systems, it can be a big driver of near-term greenhouse gas reductions. As we use more hydrogen and electricity to carry energy, RNG from organic waste streams can become a valuable part of the renewable energy supply — and a prime candidate to further decarbonization efforts.

JH: How can companies use renewable natural gas in their sustainability profiles?

JE: Beyond the commodity value, RNG also contributes to greenhouse gas reductions — adding further value in the form of environmental credits that can be monetized. It can help companies reach carbon neutrality and adhere to stringent sustainability mandates. RNG is composed of biogenic carbon; this means that any emissions released from combustion, collection or transportation of RNG are already part of the carbon cycle. Under current GHG reporting protocol, CO~2~ emissions from RNG are treated as carbon neutral. RNG consumers achieve 100 percent reduction in Scope 1 emissions; and biogenic emissions are offset by a reduction in Scope 3 emissions, based on the carbon-intensity score of the RNG. RNG with a carbon-intensity score of zero eliminates 100 percent of biogenic emissions.

At Vanguard Renewables, we get asked all of the time how a company can currently buy and use renewable natural gas. The outstanding utilization factor for RNG is that it requires no new capital equipment or system modifications. RNG utilization and the resulting reduction in carbon intensity is completed through the contractual agreement with the users’ utility or energy supplier. Supply of RNG is currently limited to certain states and regions of the country where food waste or landfill gas has been captured and repurposed, but is growing daily.

Companies that want to increase their use of renewable natural gas should take time to ensure they are dealing with a reputable seller or reseller of RNG, and that the purchaser commits to a long-term agreement — RNG is going to be in greater and greater demand as the US retail energy market becomes increasingly aware of its significant value.