When BGE became the first utility in Maryland to win regulatory approval to use renewable natural gas, or RNG, in its distribution system, the move was hailed in some quarters as a significant step in the reduction of greenhouse gases.
But some critics saw it as a smoke and mirrors approach to reducing the demands for fossil fuels.
The gas would come from a BioEnergy Devco plant under construction on the grounds of the Maryland Food Center Authority in Jessup.
Ken Durbin, the construction manager, says trucks loaded with food waste from the surrounding processing plants or even local supermarkets will pull up and dump their cargo into a funnel where it will be ground up, mixed with water, and eventually pumped into one of two giant 1.9-million-gallon tanks.
Through a process known as anaerobic digestion, it becomes the kind of gas you can use to heat your home or cook with.
Durbin says it will take about 30 days from the time they start until they “can start pumping the gas out.”
What’s left in the tanks, becomes the organic matter to start the process again and the water goes back into the tank, gets treated and “keeps getting used and used,” he explained.
Vinnie Bevivino, Bioenergy’s director of organics who has been working with the surrounding food processors, calls it a carbon neutral process.
“The carbon of our methane was once carbon that was in our air that plants have pulled out of that atmosphere made into lettuce that got digested in our digester and made back into methane,” he said. “It's completely renewable and carbon negative energy source.”
Rebecca Wolf, a food policy analyst with Food and Water Watch, scoffs at that idea. She says renewable natural gas projects are merely a distraction that doesn’t help change the model for energy use.
“It's not drawing down the amount of methane that we're using,” she said. “It’s actually propping up and creating incentives for the expansion of what we already know that we need to move away from, which is using fossil fuels or using methane.”
She was among a large group of activists opposed to similar plants BioEnergy Devco and Clean Bay Renewables are planning in Sussex County, Delaware and in Maryland’s Somerset County. Those operations would use waste products from the giant poultry farms on the Eastern Shore.
Wolf says using gas produced from waste of what she called “factory farms” only “incentivizes the build out of both gas infrastructure, as well as the factory farm model, which we know methane and the factory farm model are two big things that we need to move away from.”
Tom Spangler, one of the founders of Clean Bay Renewables, says the factory farms are a fact of life that provide the most cost-effective source of protein to feed the world. And they aren’t going anywhere anytime soon, so you have to figure out what to do with the waste from those farms.
“We view ourselves as enhancing the efforts that the poultry industry has already tried to undertake, by dealing with the current situation of being able to sustainably recycle poultry litter,” he said. “We view it as a solution as opposed to any other type of process.”
It’s not as if the environmental community is uniformly opposed to renewable natural gas projects, however.
Carlton Waterhouse, the Deputy Assistant Administrator for EPA’s Office of Land and Emergency Management, told a conference at Emory University earlier this month that anaerobic digestion is an alternative to disposing of food scraps in landfills that can create fuel to run vehicles and heat buildings.
“The highly controlled process more efficiently captures biogas than landfilling and produces a soil amendment that can be composted or land applied, thus transferring nutrients back to the soil,” he said.
On its web page, the EPA says renewable natural gas captures and recovers methane, a gas with a global warming potential more than 25 times greater than carbon dioxide, thereby providing “beneficial impacts in mitigating global climate change.”
Ryan Maher, a lawyer with the Washington based Environmental Integrity Project, agrees that anaerobic digestion beats dumping millions of tons of food waste into landfills annually and letting the methane it produces as it decays escape into the atmosphere. But he has reservations.
For one thing, he says, scientists have estimated that renewable natural gas can fill only 10% of the existing demand.
“So it's not scalable,” he said. And he raised an objection similar to that of Rebecca Wolf of Food and Water Watch.
“It distracts from the fact that a lot of other solutions are needed. So rather than building new natural gas infrastructure, the focus should be on alternative renewable energies.”
It can be part of the solution, he says, but on a small scale. And it shouldn’t be used to justify new natural gas infrastructure.
“That’s the concern,” he said. “These companies are presenting renewable natural gas as if it's as if it's a standalone fuel source, but really, it's going to be supplemented.”
Stuart Page, BGE’s manager of economic development, says his company recognizes that it will take a mix of fuel sources to meet the state’s energy needs and that there are advantages and disadvantages to each.
“But you know, we ultimately, as a utility, need to make sure that our infrastructure is ready,” he said. “And the grid is, you know, positioned to really incorporate all those different energy sources.”
BioEnergy’s Bevivino says those who question renewable natural gas because it won’t fill all the energy needs are missing the point. Renewable energy is an all encompassing strategy, he says.
“If we question solar and say, would solar create all the electricity of our needs? No? Then solar has no value,” he said. “That's not how we should be evaluating anaerobic digesters and renewable natural gas.”
Every bit of fossil fuel that’s replaced by renewable natural gas is a win, he argues. And while he concedes that the nation’s entire energy needs cannot be met by anaerobic digesters, they play an important role.
“And they play, I would say, an absolutely important role once you consider what they replace these fossil fuels or these greenhouse gas emitting landfills or incinerators that these types of materials are going to right now.”
Ken Durbin, the construction manager, says the plant should start producing renewable natural gas in the spring.
