BY JOANNA UNDERWOOD | New York’s Metropolitan Transportation Authority is joining Santa Monica, Los Angeles Transit and a growing number of other transit fleets in adopting ultra-low carbon renewable natural gas (R.N.G.). Every fleet vehicle running on R.N.G. in New York will help meet the state’s ambitious zero-carbon standard — not 30 years from now, but today.
That’s a big step forward. But R.N.G. is relatively unfamiliar to clean-energy advocates, and sometimes misunderstood. For example, the article in this newspaper’s June 20 issue (“M.T.A. drive for renewable-gas buses”) quoted Jim Walsh, of Food and Water Watch, arguing that since R.N.G. is like fossil natural gas, it could leak from pipelines and emit toxics and greenhouse gases (G.H.G.) when burned. He also said it would enable factory farms and their negative impacts. These are misunderstandings.
Yes, pipelines can leak. But according to the California Air Resources Board (CARB), R.N.G. is the lowest-carbon fuel available today, even taking potential leakage into account. R.N.G. production involves capturing methane emitted by decomposing organic wastes that would otherwise enter the atmosphere and warm the climate. CARB found that G.H.G. emitted from tailpipes of buses and trucks burning R.N.G. is negligible compared to G.H.G. captured to produce the fuel. It also found that over its lifecycle, R.N.G. made from certain feedstocks (food scraps and manures) was net carbon-negative.
That makes R.N.G. a big net gain for the climate and a prime decarbonization strategy. The fact that it is chemically similar to fossil natural gas and can be used in the same vehicles, power plants and pipelines is a good thing. It means that R.N.G. can easily displace natural gas, reducing, not compounding, the natural-gas industry’s climate impacts.
R.N.G. can also displace diesel, slashing G.H.G. and toxic emissions from diesel use. Buses and trucks equipped with “near zero” natural-gas engines can run on R.N.G., and they cut nitrogen oxide and other health-threatening pollutants to almost nothing (90 percent below U.S. Environmental Protection Agency standards).
Food and Water Watch and others are right to worry about the footprint of large dairy farms. R.N.G. shrinks it. Processing farm manures in anaerobic digesters prevents them from emitting methane and contaminating waterways, and yields renewable fuel that farmers can sell. The additional income stream can help smaller farms compete.
So what’s not to like? R.N.G. comes from an abundant, 100-percent renewable resource. It’s carbon-free, and displaces dirtier fossil fuels. Once it’s more widely understood, it should be embraced as a key part of New York’s clean energy future.
Underwood is founder and a board member, Energy Vision (www.energy-vision.org)