Imagine that the banana peel you toss into the garbage can today help power your home in the near future. It might happen sooner than you think, if it’s not already happening in the landfill nearest you. Power plants fueled by methane gases from landfills are starting to pop up all over the country. The I-E landfill in Kearny, New Jersey is one of 21 landfills in that state that pump the methane gas created by decomposing waste to use as fuel to produce electricity. In addition to pumping methane to use as fuel for electricity, the I-E landfill’s owner, the New Jersey Meadowlands Commission, has plans to install solar panels in the landfill itself. This way, space that would normally not be used for anything other than holding garbage can be more useful by providing yet another source of energy. And New Jersey isn’t the only state that’s looking to benefit from its garbage. The EPA credits 455 landfills that use methane for generating electricity, and is pursuing over 500 other landfills as potential power plants through its Landfill Methane Outreach Program.
So how does it work? Landfills produce a significant amount of methane gas due to the breakdown of municipal solid waste by anaerobic microorganisms. After the gas is produced, it can be collected by a series of connected wells that are drilled into the landfill. Then, the gas is “dewatered” and cleaned of any trace elements, and after that process is complete, the gas is ready to be used to generate electricity in gas turbines and fuel cells. Landfill gas can also be collected from small and old landfills no longer in use. Instead of using huge turbines, microturbines (PDF) are emerging as a way to generate electricity from landfill gas at a much smaller scale, although long-term costs and reliability have not been assessed yet. If these microturbines are found to be cost-effective, then they provide a great way for old and small landfills to reduce the amount of methane released in the atmosphere. Because small landfills are not under EPA regulations to curb their methane emissions, they may be responsible for as much as 40 percent of landfill methane gas in the US.
The EPA already requires large landfills to minimize the release of methane gas by some sort of collection and flaring system, so using that collected gas to generate electricity would be a beneficial way to dispose of it. Landfills have long been cited for their harmful environmental effects because of their harmful methane gas emissions, along with land use and groundwater problems. The gas build-up can cause fire and combustion in landfills, so landfills often collect and flare their methane gas to reduce this risk. Methane gas is cited as a bigger climate change agent than carbon dioxide, which is released from landfills during flaring. The methane gas that would normally be released into the atmosphere during a flaring process is reduced when used in generators. The two major issues with landfill gas treatment and power generation facilities are air quality requirements and disposal issues from the dewatering process of the methane gas. However, the emissions from the power generation are less than that of the traditional collecting and flaring process.
Landfills will likely be around for a long time and continue to produce large amounts of methane gas. Even though landfill gas will probably never power all of our household energy needs, it could provide as much as one percent of our energy needs. That seems significant to me. Considering we are in the midst of an energy crisis due to our dependence on oil, we should be looking at all the possible alternative ways of generating power. We have plenty of landfills. And, methane gas is naturally produced from these landfills that already exist and might as well be put to good use. Generating electricity from landfill gas seems like a smart solution to two major problems facing this country (and the globe) right now: global warming and the energy shortage. It’s not the only solution, but it is one step in many towards a greener, more efficient lifestyle. New Jersey’s idea of putting solar panels and possibly wind farms in old landfills is also a great idea, because landfills are already taking up space that can’t really be used for anything else. Out of the trash comes new, cleaner energy, and that’s certainly something I can support.
Photo courtesy of Flickr user D’Arcy Norman.