In previous columns, I have focused on the use of biogas as a transportation fuel, which holds enormous, untapped potential. However, my introduction to biogas energy systems was through projects that use biogas to produce electricity and then capture thermal energy from the generator for a useful purpose. This process is better known as combined heat and power (CHP) or cogeneration. 

Biogas is truly a remarkable form of renewable energy. One of the most attractive attributes of biogas is its versatility as a low-carbon energy resource. It can be burned to produce power and heat, used directly for heat, cleaned to a form that is equivalent to conventional natural gas or compressed and used as fuel for transport. Beyond its versatility, biogas can be produced from a variety of organic feedstocks, which provides a wide array of positive environmental benefits. Biogas has something for everyone to be excited about.

Over the past several months, I have attended several meetings and have had many discussions about how to increase the adoption of CHP systems in the U.S., specifically in the Midwest. The resurgence of interest in CHP was precipitated, in part, by the Obama administration’s August 2012 Executive Order on Industrial Energy Efficiency and Combined Heat and Power, which sets a goal of adding 40 gigawatts of new CHP by 2020. This would raise the CHP capacity in the U.S. by 50 percent and would require more new CHP to be installed each year than has ever previously been installed in a single year. Meeting this goal is going to be a challenge, and biogas has the potential to meet a portion of this ambitious goal.

Already, the overwhelming majority of agricultural-based biogas energy systems produce CHP. Agricultural producers, wastewater treatment plant managers and landfill gas operators have been early adopters of CHP systems. Even biogas projects, which have a primary energy output of biomethane (cleaned form of biogas), integrate CHP as a way to produce power to run clean-up and compression equipment. Projects that are using multiple technologies and components to produce different forms of energy with biogas as their base input are considered closed-loop energy systems and are dramatically reducing the overall project carbon footprint.

Increased focus on CHP deployment across several sectors—industrial, commercial and agricultural—is also leading to technology improvements from equipment manufacturers and project developers. Just like anaerobic digestion is a well-established biological process, the development of CHP system equipment is also well-established. But similar to many other industries, equipment manufacturers are always improving technology to reduce costs and increase efficiency. Off-the-shelf CHP technology packages, across a wide spectrum of generation output, are currently available and this helps to bolster streamlined deployment. However, the largest barrier of upfront capital costs with an extended return on investment still remains. States all across the U.S. are developing policy programs and incentives to overcome this barrier.

As an early adopter and implementer of CHP systems, the biogas sector stands to benefit from the increased focus on CHP deployment. There is huge, untapped potential for biogas production from a variety of organic streams. Once we are able to take advantage of this potential, biogas can be used to meet a variety of energy needs. The time and attention currently devoted to increased CHP deployment is a valuable strategy for harnessing the untapped biogas potential in the U.S.

Author’s note: This column first appeared in the December 2013 edition of Biomass Magazine.

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