New unit of energy efficiency: The Rosenfeld

It is hoped that the Rosenfeld - named after the "father of energy efficiency" Dr. Art Rosenfeld - will help standardize references to “energy saved”, rather than such variable calculations as “avoided powerplants” or “cars off the road.”

Arthur Rosenfeld is an acclaimed high-energy physicist and researcher/educator for Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California at Berkeley. He is also a two-time appointee to the California Energy Commission and has won the Enrico Fermi Award, one of the nation’s oldest and most prestigious awards for scientific achievement. As an energy scientist, Rosenfeld is perhaps best known for his role in developing the DOE-2 whole building simulation program, which continues to serve as the international benchmark for energy-efficiency simulation codes.

Dr. Jonathan G. Koomey and others from Lawrence Berkeley National Laboratory in California presented the explanation of the Rosenfeld in their article, "Defining a Standard Metric for Electricity Savings", which appears in Environmental Research Letters. It describes the Rosenfeld as:

...the average coal plant capacity of 500 MW, a capacity factor of 70% (the average capacity factor of existing U.S. coal plants from 1996 to 2007), and system-wide T&D losses of 7% (rounded up from 6.7% for ease of recall). This combination of parameters would yield annual electricity delivered at the meter of about 3 BkWh/year. Using the carbon burden for US utility coal and the efficiency of average existing coal steam plants, the emissions saved are almost exactly 3 million metric tons of CO2 (Mt CO2) per year.

Koomey and his coauthors go on to say "the Rosenfeld can best be used in rough back-of-the-envelope calculations and high-level summaries of analysis results for less technical audiences."

According to the Alliance to Save Energy, the Rosenfeld offers the energy efficiency lexicon a new tool with which to talk about climate change. By standardizing the link between energy saved and infrastructure, the term will help promote what Dr. Koomey and his colleagues call "a significant shift from the status quo ... an internalization of societal costs that heretofore have not been included in the operational and investment decisions of electric utilities."

A PDF of Koomey's article is available free at this link:

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