Ten Years of California Distributed Combined Heat and Power: Living Up to Expectations

In the last 20 years, emerging technologies such as fuel cells and microturbines have contributed to growth in the market for combined heat and power (CHP) in small-scale (5–5,000 kW) applications. Numerous studies utilizing performance assumptions have explored the theoretical potential for distributed CHP to save energy and reduce greenhouse gas (GHG) emissions, however actual performance may differ from expectations. Incentive programs in several states are beginning to yield information about actual (as opposed to potential) performance of small-scale CHP. This paper leverages over ten years of metered data from more than 500 different projects rebated by one such program: California’s Self Generation Incentive Program (SGIP). The population of projects includes established technologies (internal combustion engines, gas turbines) as well as emerging technologies. Performance measures examined include efficiencies, utilization, and GHG emissions impacts. A variety of Federal and State policies seek to increase the amount of small-scale distributed CHP in the coming years. It is imperative that knowledge about actual performance gleaned from metered data collected during the past decade be shared widely so that CHP’s potential to reduce energy consumption and GHG emissions is actually realized in the future.