New Study of Distributed Generator Emissions to be a Resource for Combating Air Pollution

October 30, 2019 Press Release

(WHITE PLAINS, NY – October 30, 2019) The Pace Energy and Climate Center (Pace) today announced a new data analysis tool and research model in a report titled Estimating the Air Emissions of Stationary Engine Generators under Two Megawatts,” both developed with support from Environmental Defense Fund. These provide detail on the number, kinds, the age and pollution emissions data from electric generators under 2 megawatts in New York State. Estimating this type of pollution more accurately and comprehensively across different scenarios, and understanding its impact, is a critical step in transforming the electric marketplace and developing policy solutions that can address the emissions these machines generate and their negative effects on air quality, health and ultimately regional and global climate.

“Almost everyone lives and works within breathing distance of one or more of these generators,” said Tom Bourgeois, research project manager and deputy director at Pace. “We were shocked to find huge gaps in our understanding of the number and characteristics of these pollution and power sources. Given the rapidly changing electricity markets and the increasing frequency and duration of severe weather, these generators are likely to run more often and create even greater pollution.”

In New York City alone there were 7,520 childhood asthma cases in 2010 attributable to particle matter 10 (PM10), a common pollutant from electric generators (see: The results of Pace’s research, which are based on the new model called Distributed Generator Emissions Tool and Inventory (D-GETI), are published in this new report, available here. This unique EXCEL based tool provides the public  previously unavailable information estimating the number of engine generators, lifetime and emissions characteristics

Electric generators under 2 megawatts, which run on fossil fuels, are part of the business and residential infrastructure of New York. The study estimates nearly 750,000 of these generators are installed across the State and many millions more across the entire country. These generators are very lightly regulated, and their climate-changing greenhouse gas emissions are not regulated at all. The study estimates that nearly 1 in 6 operating engines were installed prior to 1997, and more than 40 percent of in-service engines were installed prior to 2003. The age of in-service generators is of critical importance due to the huge difference in emissions rates of old engines as compared with current models. For example replacing a 1991-diesel generator between 150 kilowatts and 300 kilowatts with a 2016 engine of the same power size range could result in a 97 percent reduction in carbon and particulate matter emissions.

“This new research is essential for improving electricity markets while managing air pollution,” said Elizabeth B. Stein, Senior Manager and Senior Attorney, Energy at Environmental Defense Fund. “Regulators can use it to anticipate the pollution impact of real-world events that cause fossil-fired generators to operate longer or more frequently, allowing New Yorkers to breathe cleaner air.”

D-GETI uses information from a detailed database of stationary engine generator sales. It enables researchers and policy makers to more reliably estimate the emissions from these generators under a range of operating scenarios, and can be adapted to be used in different areas of the country.

“What we have done in New York can and should be replicated everywhere in this country,” said Bourgeois, “because the same market and climate factors are at work everywhere.”

About the Pace Energy and Climate Center

For over 30 years, the Pace Energy and Climate Center ( has been a leader working at the intersection of energy and the environment.  Pace is one of few public interest organizations with deep understanding of the arcane but critical world of utility service rate development and rate design. The Center prioritizes issues relating to energy justice—affordability, access to clean and sustainable energy. It’s portfolio of activities includes distributed generation, grid modernization, innovative rate design, as well as comprehensive policies addressing climate change mitigation and resilience.

About EDF

Environmental Defense Fund (, a leading international nonprofit organization, creates transformational solutions to the most serious environmental problems. EDF links science, economics, law, and innovative private-sector partnerships. Connect with us on Twitter, Facebook, and our Energy Program blog.

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