City garbage truck

by Rachel Darken, Administrative Assistant

The City launched an important and unprecedented program this summer. Now when the garbage trucks roll down our streets each week, fire trucks speed toward emergencies, or work trucks maintain our parks and traffic signals – it’s happening. This largely undetectable change is making a difference in our community.

So what is it?

Fleet has started fueling with a 20% biodiesel blend, or B20, for the first time. In fact, Madison is the second public fleet in Wisconsin after the City of Milwaukee to use B20 for all diesel vehicles.

What is biodiesel?

Biodiesel is a biodegradable, renewable fuel produced right here in the Midwest. It’s mostly made from soybeans, but can be made from vegetable oils, animal waste fats, and even used restaurant grease. It can be dispensed into virtually any vehicle or equipment that runs on petroleum diesel. Biodiesel is usually blended with diesel. For example, a blend containing 80% petroleum diesel and 20% biodiesel is called B20. Currently engine manufacturers will honor warranties if customers utilize biodiesel blends up to B20, while they continue promising research into higher blends for future warranty updates.

Impact on Environment

One of the biggest benefits of biodiesel is its ability to reduce carbon emissions. Carbon dioxide (CO2) is absorbed while soybeans and other biodiesel feedstock grows. Studies have shown that using pure biodiesel (B100) reduces CO2 emissions by 74% when compared to petroleum diesel. The higher the percentage of biodiesel, the greater the impact on air quality. There are drastic reductions in multiple other particulate emissions as well. Benefits are extended to both the local community, which will have better air quality, and the entire planet thanks to greenhouse gas reductions.

Fleet has been slowly introducing biodiesel to our fuel program for the last year. This summer marked the first time all of our ten fuel sites dispensed B20. As you can see from the diagram below, the City’s use of biodiesel is already having an impact and reducing carbon emissions.

cumulative CO2 emissions reductions in 2019 from biodiesel

Since biodiesel is produced domestically, we’re reducing our carbon footprint even further by purchasing less fossil fuels shipped from afar, including sources halfway across the world. It also lessens our dependence on petroleum diesel, which can be disrupted by trade disagreements and international politics.

Impact on Fleet

City vehicle with a winter plowMost people including City truck operators will never know the difference. Given our cold Wisconsin winters, there are a few minor considerations we use to keep equipment operating smoothly.

Just like petroleum diesel, biodiesel starts to freeze when the temperature gets low enough. To prevent any issues, we use smaller blends of biodiesel (such as B5) in the winter months, and will stop fueling with biodiesel altogether when the temperature approaches 0 degrees Fahrenheit. Fleets also should plan to change fuel filters more often when first using biodiesel.

Out of more than 500 pieces of equipment in our diesel fleet only one type of off-road equipment has proven incompatible with biodiesel: asphalt heaters used to patch potholes. These 7 Streets assets are fueled with regular diesel.

Madison’s transition to biodiesel has gone largely unnoticed – and in the fleet world that’s a good thing. The equipment is working while we take this positive step for the environment. We’re proud to be one of the first fleets in Wisconsin to fuel with B20 across the board, and we encourage all other fleets to join us. We would like to congratulate private companies Snyder and Martin Transport, Wisconsin-based businesses who have also made the leap to B20.

This content is free for use with credit to the City of Madison - Fleet Service and a link back to the original post.

Category: Sustainability