Madison, Wisconsin [RenewableEnergyAccess.com] Focus on Energy, Wisconsin’s energy efficiency and renewable energy initiative, is helping businesses become more energy independent by offering a new grant for dairy farms, wastewater treatment plants and food processing plants. These businesses can receive up to $250,000 to finance and install an anaerobic digester — a renewable energy system that produces heat and electricity from organic material.Anaerobic digestion is the bacterial decomposition of organic matter that occurs in the absence of oxygen. An anaerobic digester system is an enclosed tank that excludes oxygen and through which organic matter is passed and broken down by naturally occurring bacteria, producing biogas. This biogas is composed of approximately 55 percent to 70 percent methane. The methane produced in the process can be used in an engine-generator to produce electricity. Anaerobic digesters can also be used to provide heat.
“The electricity and heat produced from an anaerobic digester helps combat rising energy costs and reliance on imported fossil fuels,” said Don Wichert, program manager for Focus on Energy’s Renewable Energy Program. “Another benefit to anaerobic digesters is their ability to manage waste. As our society grows so does our waste, and the need to manage it becomes increasingly important. Using anaerobic digesters to manage waste makes sense economically and environmentally.”
Wastewater treatment plants and food processing plants can use the biogas collected from an anaerobic digester to help offset energy costs by providing heat, running refrigeration, supplying process heating and producing electricity and steam. Anaerobic digesters can also reduce odors, control pathogens and preserve the environment by reducing greenhouse gas emissions. A digester for a 1,000-cow dairy farm can produce enough electricity to power 150 average Wisconsin homes.
One farm currently experiencing the benefits of anaerobic digestion is Green Valley Dairy in Krakow, Wisconsin. The farm completed the installation of an anaerobic digester in March 2006. Most recently the farm was awarded a $240,000 grant to help fund a $960,000 expansion project that will improve upon their current system, nearly doubling its current production to a total of more than 7 million kilowatt hours (kWh) of electricity a year, enough to power over 700 average Wisconsin homes.
“Focus on Energy has a network of experts across the state and offers a variety of programs to help anyone plan, finance and install renewable energy systems,” explained Wichert. “Because of incentives like our new anaerobic digestion grant, a growing number of Wisconsin residents are using renewable energy.”