Waste-heat-to-power : a case study of Canadian natural gas compressor stations

Half of all primary energy input in North America is lost as unused heat. Turning this waste heat into usable energy through waste-heat-to-power (WHP) technologies could help to economically meet climate objectives. Compressor stations on natural gas transmission lines have been identified as a significant potential source of WHP, which would generate electricity with negligible incremental carbon emissions. Installations usually occur as retrofits, and are not dependent on transmission expansion or stock turnover. In Canada, ten such installations were made between 2007 and 2013, but represent a penetration of only 6% of compressor stations. This study conducts an integrated assessment of technical, economic, institutional, regulatory, and policy factors affecting WHP development to examine drivers and barriers, along with appropriate policy levers. Given the quantified installed gas transmission turbine capacity of 4.6 GW, there is over 1.1 GW of WHP technical potential on Canadian compressor stations. Combined with turbine capacity factors estimated from pipeline throughput and capacity data and costs from past installations, 0.3 GW is estimated to be economically viable. The majority of remaining viable WHP capacity is in Alberta. These are competitive with new natural gas combined cycle plants with a $50 per tonne carbon price. Investment is sensitive to the electricity purchase price, turbine capacity factor, cost of capital, and electrical grid interconnection costs. Generation is expected to be baseload or correlated to seasonal electricity demand fluctuations. Three primary barriers to implementation were discovered. WHP is not consistently recognized as a clean electricity source in all jurisdictions, including Alberta. Regulations for steam systems that require continuous on-site monitoring by appropriately certified Power Engineers add significant operating expenses. While gas compressor operation shifted to remote monitoring of automated systems following technological advances in past decades, on-site monitoring thresholds for thermal power generation have not changed since 1975 and should be reassessed to ensure benefits warrant the costs. Lastly, interpretations of cost-of-service regulations have funneled significant benefits back to gas shippers, in addition to transmission companies and WHP developers. This split incentive has reduced the attractiveness of WHP development to decision makers.Science, Faculty ofResources, Environment and Sustainability (IRES), Institute forGraduat