I am honored to be writing my first column for Biomass Magazine focused on the U.S. biogas sector. I have worked on biogas energy systems for the past decade, and it is exciting to finally be at a point where increased interest in this valuable and underutilized technology is starting to build. But make no mistake, there is far more work to be done to fully take advantage of the enormous potential of biogas.
The very first biogas energy system project I was involved with was at a Minnesota dairy farm that installed a plug-flow anaerobic digester, in 1998, and used the collected biogas to produce renewable electricity and heat. My organization, at the time, was the coordinator for a team of University of Minnesota researchers and interested stakeholders studying the impact of using digested manure as a fertilizer, the ability of anaerobic digestion to destruct weed seeds in manure, and the economics of the entire system. According to the U.S. EPA AgStar program, today there are 192 biogas systems using manure and other organic resources to provide a source of renewable energy. But we could and should be doing much better, not only in the utilization of livestock manure, but all organic waste streams.
As an example, this last year, I collaborated with Joe Kramer at the Energy Center of Wisconsin to examine the current barriers and future opportunities for U.S. swine farms to adopt anaerobic digestion and produce renewable energy, while supplying additional environmental benefits. Our research found there are some technical and policy barriers that need to be overcome to take greater advantage of this resource, but these barriers are not insurmountable, and there is great promise for increased adoption at swine farms. There are countless other organic waste streams that merit closer examination.
The past several years have witnessed some incredibly exciting developments that present a real opportunity to put organic waste streams to work in a much larger way towards providing a source of renewable energy to meet our electricity, thermal and transportation energy needs. The opportunity to combine organic waste streams together, known as co-digestion, is beginning to grow. This is significant, because when we combine manure with a higher-carbon source such as fats, oils and greases or food processing waste, projects can greatly increase overall biogas production, and this can have a positive impact on project economics.
There have also been projects that have pioneered the ability to remove carbon dioxide and other trace gases or impurities to produce a product that is equivalent to natural gas and can be injected into the natural gas pipeline to meet thermal energy needs, or supply a source of fuel for the natural gas vehicle market. Projects have also experimented with the ability to clean and compress biogas closer to the site of production to supply biobased compressed natural gas to a refueling station.
Not only has the U.S. biogas sector been working hard to expand the energy utilization opportunities for biogas, but it has also aggressively pursued projects that capture biogas from our nation’s landfills, municipal wastewater treatment facilities, industrial wastewater treatment and constructed projects to combine waste streams from multiple sources such as livestock manure, food-processing waste, crop residues or source-separated organics from households and institutions. There are new projects slated for construction this year, and I believe we will observe new development models, diverse feedstock utilization and increased demonstration of biogas’s ability to supply renewable energy options to the underserved thermal and transportation markets.
Each of these developments are major leaps forward, and when taken together, clearly demonstrate the ability of biogas energy systems to more-effectively manage organic waste streams while supplying a reliable and flexible source of renewable energy. Biogas is unique when compared to other traditional renewable energy sources in its ability to meet electricity, thermal or transportation fuel needs, while making a contribution toward reducing greenhouse emissions and providing multiple other environmental benefits.
Even with all the valuable benefits biogas energy systems provide, and recent project developments that create real opportunity to expand the U.S. biogas market, the pace of growth is still too slow. Luckily, there are many advocates of increasing the use of biogas to help meet our nation’s energy needs, and multiple companies and interested stakeholders working incredibly hard to get projects installed that demonstrate the ability of biogas to help us achieve greater levels of renewable energy production while providing multiple environmental benefits. I am excited to use this column in the coming year to share with you exciting industry and policy developments that will move biogas into the spotlight for its contribution towards building a better energy future.
Author’s note: This column first appeared in the April 2013 edition of Biomass Magazine.