ComEd and Constellation sign carbon-free energy matching agreement

19 September 2023


US utility Commonwealth Edison (ComEd – part of Exelon) and Constellation have announced an agreement that will help ComEd power all of its 54 offices and metered facilities with locally produced carbon-free nuclear energy, every hour of every day. This will make ComEd the first US investor-owned utility to power its facilities with 100% clean energy produced at the same time and place it is consumed. The ComEd agreement follows a similar one between Constellation and Microsoft in July to power one of its Virginia data centres.

Constellation noted that hourly matching is seen as an evolution in the clean energy transition. Currently, most companies pursue net-zero goals by buying annual renewable energy certificates (RECs). These represent units of clean energy produced by a solar or wind facility located somewhere in the US during a given year. This means a manufacturer in Virginia could buy enough RECs in April in Iowa to match its annual energy use and then claim its operations in August run on clean energy. However, such annualised RECs represent energy that was produced halfway across the country at a different time of day and year. Meanwhile, the manufacturer will receive most of its energy from a nearby fossil-fuelled plant.

The sale of RECs helps to spur renewable energy investment but also means developers prefer to build those facilities in locations that already have significant wind and solar resources. This regional overproduction of renewable energy also causes problems for local grid operators because there may be no way to move the excess energy to where it is needed.

In 2021, a White House Executive Order recognised hourly carbon-free energy matching as “critically important to advancing the nation’s clean energy goals”. It directed federal agencies to work together to ensure that 50% of all federal buildings are hourly matched with clean energy by 2030.

In 2022, Constellation and Microsoft announced a collaboration to develop an advanced software and analytics solution to help companies match their energy use every hour of the day with locally produced carbon-free electricity. Microsoft subsequently became the first customer to use the technology. “Our work with Constellation is part of what we hope will become a movement for businesses of all kinds to transition to truly carbon-free operations,” said Adrian Anderson, general manager of renewable and carbon-free energy at Microsoft. “We are pleased to see that more companies are choosing hourly matching as part of their sustainability strategy.”

Constellation President & CEO Joe Dominguez said matching clean energy production to the time and place where it is used “is the only way we will truly achieve zero carbon emissions across our economy”. He added: “Following this summer of record-shattering weather, it’s clear that hourly matching needs to become the standard within our industry for the US to have any reasonable shot at reaching its 2050 climate goals and preventing the worst effects of climate change. Our agreements with ComEd and Microsoft show that American businesses want a better approach to carbon accounting, and that nuclear energy is key to delivering it.”

ComEd’s hourly carbon-free energy purchase will match its anticipated electricity use of about 65,000 MWh, which includes its corporate and regional headquarters, reporting centres, business offices, training and special use facilities and substations. “ComEd is committed to doing everything possible to help Illinois achieve its goal of 100% clean energy by 2050, and that includes reducing the use of fossil fuels and lowering carbon emissions at our own facilities in every hour of every day,” said ComEd CEO Gil Quiniones.


Image courtesy of Constellation



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