Avoiding the worst impacts from climate change will require throttling back on fossil fuels. While many electric utilities in the Northwest are beginning to understand that clean, renewable power is their only possible future, the gas utility sector is taking a different tack with a new pipe dream: renewable natural gas (RNG). These utilities aim to position RNG as the answer to decarbonization. It’s an answer that would allow them to continue to grow their customer base, lock in profits from new infrastructure investment, and green up their image. Unfortunately, their RNG strategy rests on faulty assumptions and fuzzy math, plus a bit of deception. In the next article in this series, we’ll explore some of the deceptive tactics that utilities are deploying. But first we’ll dive into the fundamentals of RNG.
What is RNG, and where does it come from?
RNG is methane gas, chemically identical to fossil natural gas but sourced from decaying feedstocks. Nearly all available RNG is siphoned off landfills, sewage treatment plants, or livestock manure ponds on large industrial farms. These places are rich sources of RNG because when animal waste and trash decay, the microbes that break down the waste produce gases that contain methane, which can, in turn, be captured, cleaned up, and pumped into a pipeline. Today, many waste facilities already capture their methane gas and use it on-site to generate heat or electricity. Farms also sometimes capture the gas for on-site heat and power, though it is more common for them to release the gas from manure ponds into the air, where it becomes a greenhouse gas in the earth’s atmosphere.
Another flavor of RNG is synthetically manufactured, either from inciting chemical reactions between molecules of water and carbon dioxide or from thermal gasification of biomass like crop residues or debris from logging operations. Synthetically produced RNG is still in the early stages of commercialization, as developers have completed only a handful of demonstration projects, with a few larger-scale plants in the European Union online or in construction.
RNG’s Four Fatal Flaws
On the surface, RNG seems like a promising solution, one with enviable branding: it’s both renewable and natural! But a closer look reveals that RNG is hardly a panacea.
On the surface, RNG seems like a promising solution, one with enviable branding: it’s both renewable and natural! But a closer look reveals that RNG is hardly a panacea.
Although it may play a niche role for a few select purposes, even large-scale RNG deployment would not allow us to keep up business as usual while decarbonizing. RNG has four fatal flaws: availability, cost, carbon intensity, and industry obfuscation.
Fatal Flaw 1: Availability. There simply isn’t enough RNG to replace our current consumption of natural gas—not even close. In 2019, gas usage in the Northwest states of Idaho, Oregon, and Washington totaled 710 million BTUs of gas of the 27 billion BTUs of gas consumed throughout the United States. These quantities far outstrip even the rosiest projections for RNG development. Industry-influenced studies by ICF estimate that RNG could fill in as much as 16 percent of current gas usage nationwide, if all sources were developed. Unfortunately, that’s only about half of what’s currently used by the hard-to-decarbonize industrial sector, which accounts for 30 percent of the nation’s gas consumption. (In Cascadia, industry uses a somewhat smaller proportion of the total amount of gas used: 32 percent in Idaho, 24 percent in Washington, and 20 percent in Oregon.) To the extent that any RNG is commercially available, it should probably be reserved for industries that cannot easily replace gas with electricity and have no other cost-effective alternatives for decarbonizing. In fact, studies by Energy Transitions Commission and Rocky Mountain Institute suggest that using RNG for residential or commercial purposes would be misallocating a “precious” resource because these sectors can be transitioned to all-electric clean power relatively easily.
Fatal Flaw 2: Cost. RNG is very expensive relative to other energy sources. Today, a million BTUs (MMBTU) of natural gas costs $3.67. According to a 2019 study prepared for the American Gas Foundation, about 44 percent of prospective RNG projects can be developed at a cost of $7 to $20 per MMBTU, with a median cost among those of approximately $18. The remaining 56 percent of potential projects exceed $20 per MMBTU. Many of the lowest-cost RNG projects (those developed from waste streams that are large, centrally contained, and conveniently located near existing pipelines) have for the most part already been developed. What remains are the costlier projects: smaller facilities farther away from pipelines, and biomass that is dispersed and therefore costly to gather and process. Even if we were to replace fossil gas with RNG and continued to use combustion appliances, they would cost a mint to operate. Monthly bills could easily increase fivefold. It would not take too many months of sky-high bills to justify replacing gas equipment with efficient electric alternatives.
Fatal Flaw 3: Carbon intensity. RNG has a big carbon footprint. All told, the emissions from natural gas account for nearly a quarter of greenhouse gas emissions nationwide. A clean fuel, it is not. RNG is chemically identical to conventional natural gas, which means that it, too, is largely composed of greenhouse gases. It travels through the same leaky distribution pipelines as conventional natural gas, sending small amounts of super-warming methane into the atmosphere. And when RNG is burned in our appliances, it produces exactly the same amount of carbon that conventional natural gas does.
The emissions savings from RNG, such as they are, come from preventing the release of the “renewable” methane from decaying feedstock sources like landfills, sewage, and manure lagoons. Yet alternatives to generating this methane in the first place abound, and there is a risk that commercializing RNG could actually increase its impacts on the environment. According to a report by California Climate and Agriculture Network, a profitable market for manure-based RNG likely increases localized pollution by reinforcing industrial livestock farming practices that result in liquid-based manure storage and crowded feedlots. If farms pasture-raised their livestock, they could avoid generating much of the methane to begin with. Similarly, diverting landfill-bound waste to recyclers or composting facilities—or simply curtailing the sources of trash—could significantly decrease methane production from landfills.
In all fairness, a full accounting of the emissions from substituting RNG for conventional natural gas or diesel shows that it results in a net decrease. In fact, all told, emissions from RNG are likely to be 55 to 60 percent of conventional natural gas when it is sourced from a landfill or sewage treatment plant, as is most common. Therefore, it may make sense to substitute RNG for natural gas where a net-zero carbon solution doesn’t exist (as is the case for some industrial processes), but from a decarbonization perspective, it does not make sense to use RNG where gas could be simply replaced with net-carbon zero electricity.
Fatal Flaw 4: Industry obfuscation. The gas industry is using RNG to greenwash its image while obscuring its real objective: growth at the expense of the climate. By marketing RNG as a “renewable” solution to greenhouse gas emissions, the gas industry is drumming up excitement for a product it cannot deliver. The industry aims to create the illusion that our gas system can be decarbonized by introducing a new fuel that can offset today’s gas demand, when in reality, it would offset only a small portion of that demand. If the public buys the pitch, it will enable gas companies to invest millions more dollars into new infrastructure that would lock in decades of profits. The result would be consumers paying higher prices for a façade of greenhouse gas reductions.
The tall tales about RNG don’t stand up to scrutiny. Although there may be some modest climate benefit for a few niche applications like heavy industry, it cannot be a replacement for the way we use natural gas now. There isn’t enough of it, it’s too expensive, and it’s bad for the climate. Worse yet, it lets the industry get away with spinning yarns that will benefit gas company bottom lines at the expense of everyone else. In a follow-up piece, we’ll take a closer look at the tactics Cascadia’s gas industry is using to weave these pipe dreams.
Eric Redman
No one claims RNG is a panacea — that’s just a straw man that’s easy for you to knock down. If our objective is to replace fossil natural gas, then three things (at least) are needed: electrification, RNG, and some add’l fuel, probably Hydrogen, that’s carbon-free (but also not yet available at scale). There is not enough of any of these three, including electricity, to replace fossil natural gas in the US — just to replace NG heating/cooking loads with electricity wd require a doubling of total installed US generating capacity, which is not going to happen. Meanwhile, as you note, all the carbon in RNG feedstocks will end up in the atmosphere one way or another (unless geologically sequestered). The RNG should therefore be used to displace fossil NG at the burner tip, molecule for molecule — not flared as raw biogas, e.g., but used for industry, transportation, etc. And BTW although there can never be enough RNG to replace fossil NG by itself, there is much more RNG possible than ppl usually think, because woody biomass is rarely used today for RNG or liquid biofuels. But it should and will be. Please don’t confuse the actual if non-panacea virtues of RNG with the tactics of gas utilities that you dislike; the same type of confusion set back carbon capture & sequestration for at least a decade, and we can’t get that lost time back. The renewable natural gas itself is not a falsehood — it’s real. And within its limited but not trivial admittedly non-panacea sphere, it is a definite climate benefit.
Phil B.
Great primer! I worry about RNG infrastructure & incentives being used for fracked gas support down the road. We’ve seen this sort of thing before.
Ethan Seltzer
There is no such thing as “renewable” natural gas. There is “recovered” natural gas, or “(re)processed” natural gas, or “nonfracked” natural gas, but if we keep calling it “renewable” we only play into the hands of those who want to distract our attention from the need to decarbonize our energy sources generally. This is a useful primer but it would be refreshing to add a fifth point calling attention to the fallacy of using “renewable” anywhere close to “natural gas”. Thanks!
Eric de Place
Ethan, that’s an important point and I’m glad you raised it. We’ll try to address that in our next installment on RNG. An awful lot of the debate over RNG is cast in distorted terms that are designed to advantage the industry.
Mr. Rafe Sunshine
I understand that Ballard Industries of Vancouver is proposing using their fuel cell technology for hydrogen power for freight/ passenger trains and cargo shipping. Can CH4 (methane) be split into C and H4, the hydrogen being used for propulsion in these polluting/ increased carbon emission forms of transportation?
Zane Gustafson
Yes, methane can be used to produce hydrogen, although the chemistry a more complex than simply splitting the methane molecule. And yes, hydrogen can be used as a transportation fuel for Fuel Cell Electric Vehicles.
Laura Feinstein
The vision is that hydrogen will be produced via electrolysis from water (H2O). There is another process beyond that to make synthetic methane (CH4) by combining the hydrogen from water with CO2 from some sequestration source. These processes are both pretty electricity-intensive and are pretty immature technology-wise. But, in a few years, we’ll probably see more of both. The economy is still going to need some alternative fuels to augment clean electricity for things such as aviation and heavy-duty transportation as you mentioned.
Patricia Page
I was struck by this article’s parallels in the Cost and Availability sections to the tactically delaying arguments made against solar and wind power in earlier days. And buried within the article was the “good news” which should have led: that reclaimed (rather than renewable) gas is an improvement over fossil-derived gas where gas is required. The facts are the same, but one approach is oppositional and the other midwifes cooperation in a Best Use scenario. I take encouragement from the notion that change will come more quickly if we cooperate, collaborate rather than oppose whenever we can see our way to do that.
Eric de Place
I think there are some key differences relative to the delay arguments that were used against solar and wind. Among them, RNG is only projected to get more expensive the more it is deployed (because the low-cost stuff is already captured and/or there isn’t much of it). More importantly, hoping for RNG runs the very meaningful risk of incenting another round of capital investment in gas distribution infrastructure that could well prolong the fossil fuel economy. Wind and solar are exactly the opposite.
Jay Mirro
The flaws make a lot of sense. However, I am worried that the Author did no really stress the importance of harvesting methane for Livestock facilities. The methane generated is a serious GHG and something needs to be done with it. Large livestock and leaking landfills are no going anywhere so something needs to be done that methane.
Eric de Place
Jay, we agree that capturing methane from those facilities makes sense. But we should also be careful not to provide them with a financial incentive because, after all, we don’t want to make industrial scale livestock facilities and landfills more profitable. The key point we’re trying to make is that RNG cannot serve as a replacement for fossil gas — there isn’t enough of it and it’s too expensive — and it shouldn’t be used as an excuse to slow decarbonization. And it shouldn’t be used as an excuse not to decommission gas infrastructure.
Jan Steinman
I’d like to make an argument in favour point-of-use capture and used of methane.
If farmers capture methane from farm activities, and use that methane for heating and cooking, what harm is done?
I agree that setting up an entire new industry that will ship materials from afar to make methane that goes into pipes and shipped to afar is A Bad Thing™.
But surely, there is no harm done in capturing methane that would otherwise go into the atmosphere, and using it on-site?