How Landfills Can Make Trucking Cleaner

I like to promote ways to reduce waste and send less stuff to landfills. But landfills can be useful. Closed landfills are often covered with grass and trees. That city park near you where children run down the hill in the summer and sled down it in the winter? The hill might be made of garbage. Mount Trashmore Park in Virginia Beach is just one of many parks built on old landfills.

Landfills are also helping to power the transition to cleaner vehicle fuels. As trash decomposes in landfills, it releases methane, a greenhouse gas. Landfills in the US emit a huge amount of methane. Annual methane emissions from landfills are about the same as total carbon emissions from electricity, heating, and transportation for the entire state of Alabama.

Image from Rethink the Bins. Created by Sirajum Munir Galib.

Methane from landfills is a problem, but it is also an opportunity. Technology exists to capture the methane and turn it into renewable natural gas (RNG). The Landfill Methane Outreach Program in the US tracks data from landfills all over the country. More than 1200 landfills in the LMOP database already collect methane and convert it into natural gas. Hundreds more are likely candidates for this technology, and the US government will, hopefully, follow through on its plans to expand the program.

The compressed natural gas (CNG) that heats our homes, supplies our gas stoves, and powers some large vehicles is compressed methane. It typically comes from deep underground. Even though CNG is often promoted as a cleaner alternative to petroleum, it is a fossil fuel. Extracting natural gas increases carbon emissions.

But RNG is different. By capturing methane from landfills or dairy farms (cattle produce methane), RNG production reduces the amount of the gas released in the atmosphere. As for emissions occurring when the gas is burned, those are the same no matter the original source.

Back to vehicles. I attended a virtual conference, Transform USA, that featured a presentation from TruStar Energy. The company helps business convert heavy vehicle fleets from diesel to RNG. As I and many other have mentioned, clean diesel is a myth. Electric trucks are one alternative, but that option is best for garbage or local delivery trucks that have access to nearby charging stations. Also, 18-wheelers are large and heavy and would require huge batteries to achieve anything near a reasonable driving range.

For long-haul trucking, battery power isn’t workable. That’s where alternative fuels come in. Natural gas greatly reduces emissions from driving compared to diesel and driving range is similar. RNG is especially appealing because it takes advantage of existing sources of methane like landfills.

Several barriers stand in the way of switching all long-haul trucks from diesel to RNG. First, fueling stations don’t exist everywhere. It takes at least six months to build a new station and costs up to $1.8 million. Diesel is cheap and readily available. Also, the supply of RNG is limited. According to the conference presenter, there’s enough supply to convert about 8-10% of the trucking industry. Still, 10% is better than nothing.