Nicholas Institute for Environmental Policy Solutions

Seminar Series: Darmawan Prasodjo

Date and Time
Friday, October 12, 2012 - 10 a.m. to 11:30 a.m.


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Darmawan Prasodjo, research economist at Duke's Nicholas Institute for Environmental Policy Solutions, will present "An Economic Study of Biogas Infrastructure Design in North Carolina."

Currently, the biogas to electric generation system has been implemented on a very small scale in North Carolina. According to the compliance schedule of the North Carolina Renewable Energy Portfolio Standards (REPS), the electricity generated from swine waste has to reach 0.07%, 0.14%, and 0.20% of the total retail electricity by 2012, 2015, and 2018, respectively. This goal provides the opportunity for the state to explore the potential of scaling up the implementation of renewable energy production from swine farms. This report describes the design and application of OptimaBIOGAS, which combines economic and spatial optimization to minimize the cost for constructing the biogas to electricity generating systems by considering the spatial arrangement of the swine farms, transmission pipelines, biogas conditioner, and power generators. A large scale biogas pipeline infrastructure does not exist yet and, at this early state of design, we use OptimaBIOGAS to explore how efficiencies and economies of scale, in the process of scaling up, can be affected by 1) distance between swine farms, 2) the amount of gas produced, 3) the level of cooperation among farms, 4) and whether to generate electricity directly or connect to the existing natural gas pipeline. We showcase the capabilities of OptimaBIOGAS by deploying it with various arrangements. First, we generate electricity onsite without economies of scale. Second, we purify and compress natural gas onsite and pipe it individually to the natural gas network. Third, we transport gas to a local hub, purify it and generate electricity at a larger scale. Fourth, we transport gas to a local hub, purify and pressurize it, and transport processed gas to an existing pipeline. This comprehensive report highlights the importance of systematic planning, for biogas infrastructure at different levels of cooperation between biogas sources.

This biogas infrastructure design research is a collaboration between the Nicholas Institute for Environmental Policy Solutions and the Duke Carbon Offsets Initiative. The team consists of Tatjana Vujic, David Cooley, Jonas Monast, Tim Profeta, Sung-Kang (Ken) Yeh, Meng-Ying Lee, and Yichen (Aaron) Lu.