In addition to committing to wind and solar power, DTE Energy has been at the forefront of renewable energy by developing and operating landfill gas facilities across the country.  Now, DTE Biomass Energy is taking renewables one step further by harnessing the power of a seemingly unlimited fuel source:  cow manure. By using this waste stream to create renewable natural gas (RNG), DTE Biomass Energy is helping farmers reduce their environmental impact while simultaneously improving dairy farm profitability.

A leader in renewables

For 30 years, DTE Biomass Energy—a part of DTE Energy’s Power and Industrial group —has been dedicated to building and operating landfill gas-to-energy projects. By capturing the methane gas naturally produced in landfills, DTE has created a sustainable source of RNG while providing landfill owners with a consistent revenue stream. The Biomass team has now brought this renewable gas expertise to the agricultural sector.

“If you’re not a farmer or living close to a farm, cow manure, let alone the potential of cow manure probably isn’t something you think about,” explains Kevin Dobson, vice president of business development for DTE Biomass Energy. “But for anyone in the renewable energy space, it’s an exciting opportunity.” 

DTE Biomass Energy has recently opened the first dairy-based RNG processing facility in the state of Wisconsin. This is the perfect place to begin operations as Wisconsin is the second largest dairy producer in the country and has the most licensed dairy farms of any U.S. state. “Investing in dairy RNG is a good strategy for DTE because of the ever-increasing demand for renewable energy,” Dobson points out.

Cows: a sustainable fuel source

The average dairy cow can produce 80-100 pounds of manure every day. With farms that have herds that number in the thousands, that is a lot of waste that needs to be managed. Farmers typically use this manure as a fertilizer on cow feed crops. Unfortunately, this releases greenhouse gases into the atmosphere, creates unpleasant odor pollution and can leech harmful elements into local groundwater. Creating RNG from this waste is a safer and more sustainable solution.

The process to create RNG is simple. Dairy waste (i.e., cow manure) is deposited into an anaerobic digester where bacteria produce a biogas consisting of primarily methane (natural gas) and carbon dioxide. DTE RNG facilities strip out the carbon dioxide and other impurities from the raw biogas, producing pipeline quality renewable natural gas. The RNG is compressed and can either be trucked to a pipeline injection facility or directly injected into a natural gas pipeline. Once injected, that RNG is transported via dedicated interstate natural gas pipelines to vehicle fueling stations where it is used in compressed natural gas (CNG) fueled vehicles.

The solid byproduct of the anaerobic digester is also valuable to the dairy farmer. The solids that comes out of the anaerobic digester are less odorous and pathogen free making it ideal for either crop fertilizer or animal bedding.

Renewable natural gas produced from dairy cows is especially exciting because this fuel source is available 24 hours a day, 7 days a week, in nearly any climate. Cows don’t take vacations from producing manure!

“Let’s not forget the human side of this story,” Dobson concludes. “Dairy RNG facilities are valuable to the local economies as they provide a revenue stream for dairy farmers and jobs at our RNG facilities. Our projects are also good for our planet because they reduce overall greenhouse gas emissions, improve water quality and provide an alternative source of energy to fossil fuels.” Dairy farms are an important part of the U.S. economy, but the large amounts of waste created have serious side effects. Together, DTE and dairy farmers can produce a profitable and sustainable natural gas that ultimately combats climate change.

Learn more about DTE’s RNG programs at https://dtepowerandindustrial.com/.