Anaerobic Digester: Richard Roach
White County – Monticello, IN
Running 24/7 in Monticello, Indiana, is the RAKR Farms’ anaerobic digester, turning food waste and manure into electricity and fertilizer. If you’re looking to understand the circular economy, look no further than the anaerobic digester process. The Roach family uses food and livestock manure to create energy and fertilizer, the energy and fertilizer are then used to help power the farm and grow crops, some of those crops go to feed livestock, and finally the waste from livestock is returned to the digester. The process starts all over again, creating a circular cycle. The digester produces just under 1.1 megawatts (MW) of electricity which is enough energy to power 940 homes and fertilize thousands of Indiana cropland acres. Citing reliability as one advantage of this form of clean energy, Richard Roach, farmer and member of the RAKR operation says, “Digesters are unique compared to the other renewable energy sources where you’re dependent on the sun to shine or on the wind to blow.”
What is a Digester?
An anaerobic digester has many components that work together to produce power. First is the digester itself. The digester does just that; it digests raw materials, like a stomach would. Organic materials like food waste and manure are broken down by bacteria in the absence of oxygen. This process produces methane gas (biogas) and digestate (leftover solids and liquid). The methane is burned by an engine which powers a generator that finally sends electricity up and out onto the energy grid. The digestate is discharged from the tank and used as a natural fertilizer for RAKR farms.
The facility takes in 30-35,000 gallons of organic product a day into a 1.2 million gallon tank, with 15 percent of that being manure. Food companies in the region pay RAKR Farms to take excess food waste and turn it into energy. It’s cheaper for these companies to bring their waste to the Roach’s facility than to pay for the space in a landfill, not to mention it is more sustainable. “We’re viewing it as a value-added process, converting waste into electricity. I think that’s pretty neat, ” Richard says proudly.
Deciding to Build a Digester
The Roach family became interested in this project after learning about the benefits it offered like increased income, energy savings, and natural fertilizer production. They started researching in 2009, and the project wasn’t up and running until 2013. Richard recalls that digesters were not commonly practiced when they started to get serious about building one. “At the time, it was fairly new technology in the U.S. so finding somebody that we trusted to design and build this facility was kind of the first step.” Once they found a provider for the technology and construction, they looked into USDA grant opportunities for renewable energy, which they received to help finance the operation. Finally, they obtained the required permits and set off to build. “Everything you see here from the buildings, to the tanks, to the concrete did not exist before. So really, the original capital investment was just starting with bare dirt and building what we have now,” he explains. Like any farm equipment there is regular maintenance involved, but Richard doesn’t feel as though the digester’s maintenance is overwhelming. The costs vary year to year but include maintenance of pipes, valves, and engines. RAKR Farms saw a return on investment of their upfront costs and maintenance within 10 years, not including the amount they save each year on fertilizer or the payments they receive for taking in food waste.
When asked about the benefits of the digester, Richard listed three ways of looking at it: “…there is sustainability for the future…financial, and then you can look at agronomic benefits, too.” The process of turning organic waste into energy helps power RAKR farms, they receive a fixed income from the energy produced, and the digester provides fertilizer (digestate) that they would otherwise have to buy commercially.
Richard believes in the potential of this project and the viability of digesters for other locations, as well. “It can really change the way production agriculture is viewed. This process just keeps giving back, it’s a closed loop. Through the ebbs and flows of the ag economy, this has been a constant for us.”
To learn more about Richard Roach’s renewable energy experience and his family’s anaerobic digester, watch IN-ACRE’s interview with him here.