Turning Waste into Vehicle Fuel: Renewable Natural Gas (RNG) - A Step-By-Step Guide For Communities
Energy Vision is a national 501 (c) (3) organization based in New York City whose goal is to promote - through research and action - a swift transition to pollution-free renewable energy sources. Programmatically, Energy Vision informs and engages with policy, business, and environmental leaders, to support the shift of medium- and heavy-duty bus and truck fleets along the path toward a sustainable fuel, especially renewable natural gas.
This report was prepared by Energy Vision President Joanna D. Underwood and Director of Research and Outreach Matthew P. Tomich.
Energy Vision wishes to express appreciation to the many stakeholders and interested parties that contributed information, data, and technical assistance. This work was supported in part with a Brookhaven National Laboratory subcontract from the Department of Energy’s Clean Cities Program.
- Authors / Editors:
- Joanna D. Underwood and Matthew P. Tomich
We are pleased to offer this new Energy Vision Guide. It aims to empower local community citizens and stakeholders and other municipal, county, and state leaders across the U.S. to take advantage of an energy resource that can contribute immeasurably to both a healthier and better quality of life for their residents and a stronger economic future for our country. That resource is what Americans have for decades considered “waste.”
Every year, U.S. households, institutions, factories, and farms throw away so much garbage, yard trimmings, crop residues, and other organic wastes that, if turned into a source of energy, it could power almost every urban truck and bus fleet in the nation. This fuel, called “renewable natural gas” (RNG) or “biomethane” is interchangeable with fossil natural gas but has distinct advantages over it. Waste-based natural gas generates close to zero greenhouse gases on a well-to-wheels basis, produces almost no health-threatening particulate emissions, and its production requires no drilling! By throwing away all manner of organic wastes, Americans have actually been destroying a vast renewable fuel feedstock while also draining public budgets.
This Guide has two overall goals: The first is to clarify the distinct and significant contribution that waste-based natural gas can make in reducing U.S. dependence on oil – primarily for transportation fuel – that puts our country’s environmental, health and economic future at risk. The second goal is to provide communities with the steps they can take to turn their residential and commercial organic wastes, and possibly the organic wastes generated locally by farms, dairies, food processing plants, restaurants and other such sources, into a clean, secure, money-saving fuel solution.
RNG can be used to generate power, to heat homes or to fuel vehicles. Perhaps most important, it can significantly reduce our country’s dangerous dependence on oil. The largest share of the oil we use goes into transportation, and while solar, wind, geothermal and other renewable energy sources are available to generate power for residential, commercial, and industrial uses, renewable as well as fossil natural gas are among the few fuels that have the commercial potential to really slash our need for foreign oil today by replacing the use of diesel in fleets of medium- and heavy-duty trucks and buses. These fleets constitute less than five percent of all road vehicles. However, they consume about 23 percent of all on-road fuel, which equates to about 13 percent of total U.S. oil consumption.
How much diesel fuel could RNG displace? Estimates vary, but all are substantial. According to a study byQSS Group, funded by the U.S. Department of Energy in 1998, the practical RNG production potential from organic wastes was about 10 billion diesel gallon equivalents – more than 25 percent of the 38 billion gallons of diesel consumed a year. Two more recent studies, a 2011 report by the American Gas Foundation and a 2012 study by the American Petroleum Council, estimated more conservatively that RNG could replace 6.4 billion gallons (16%) of today’s diesel consumption, using commercially available technologies.
Both studies, however, indicated that it will be possible to make much more RNG in the future from wood wastes and crop residues with “gasification” technology (which is under development now) –enabling RNG to displace about 50 percent of diesel consumption – or some 17.9 billion gallons a year. But gasification technology is not yet fully commercial, and this guide focuses on technologies that are widely used today.
RNG (as does fossil natural gas) offers communities greater fuel price stability and fuel security for the indispensable “workhorse” services provided by medium- and heavy-duty truck fleets that collect garbage and recyclables, that handle emergency response, maintain roadways and deliver products, as well as bus fleets that take children to school, commuters to work, residents to airports, etc. RNG also provides a secure fuel for the trucking sector that, within cities and on long-haul routes, transports a whopping 70% of the nation’s Gross Domestic Product in the form of raw materials and products from the farthest reaches of the country to every possible locality.
While the increased domestic production of oil in the last few years has given the U.S. a more stable supply, the environmental impacts of this expanded production, including the use of “fracking” techniques for tight oil, are not fully understood. Despite these advancements, as a global commodity, the price swings of oil and the growing risk of supply disruptions – as world competition grows for shrinking global petroleum supplies – still threaten the stability of cities and communities as well as this country’s national economic strength.
RNG provides communities with a clean-burning fuel that virtually eliminates the pollutants associated with diesel exhaust, including particulates (soot) that are linked to cardio-vascular disease, cancer and childhood asthma, and smog-forming nitrogen oxides. While RNG would also produce cleaner emissions if used in power plants, when it is used in bus and truck fleets, it is safeguarding urban and suburban residents from diesel emissions that especially threaten the health of children, the elderly, and those with respiratory conditions. In June 2012, diesel fumes were labeled a “known carcinogen” by the World Health Organization.
Both RNG and fossil natural gas can help communities meet their carbon emissions reductions goals, but RNG does so even more effectively. While fossil natural gas can reduce vehicle carbon dioxide (CO2) emissions by 20 to 25 percent compared to diesel fuel, RNG can reduce the carbon footprint of diesel by 88 percent or more. It is the lowest of all low-carbon fuels available for transportation, according to the life-cycle analyses of the California Air Resources Board and Argonne National Laboratory. When considering the production, transport and use of the fuel, RNG comes close to a zero carbon footprint and can even be carbon negative when produced from food waste.
We want to express our thanks to Brookhaven National Laboratory and the U.S. Department of Energy’s Clean Cities Program, whose support made preparation of this Guide possible, and to the companies and municipal officials whose projects are discussed in the Guide. We hope the information on their initiatives will inspire others to embrace a fuel option that can help move our country toward a sustainable transportation future.