Microgrids Should be Powered by Renewable Energy, Not Dirty Fuels

Chairman Willie L. Phillips
Commissioner Richard A. Beverly
Public Service Commission of the District of Columbia

Dear Chairman Phillips and Commissioner Beverly,

The Sierra Club hereby provides comments in response to the Notice of Inquiry regarding Formal Case No. 1163, In The Matter Of The Investigation Into The Regulatory Framework Of Microgrids In The District Of Columbia.

The Sierra Club applauds the Commission for your efforts to push forward grid modernization. When powered by local renewable energy sources, microgrids can play an extremely valuable role in advancing the District’s clean energy and resiliency goals. However, when the grids are not powered by renewable sources or powered jointly by some combination of renewables and fossil fuels, microgrids can stand in direct contrast to the District’s climate commitment of carbon neutrality by 2050.

All too often, microgrids are constructed with a substantial role for fossil fuels as a generation source. For example, the microgrid in Eastman Business Park in New York state (which is cited in the Commission’s Notice of Inquiry) uses a coal-fired cogeneration plant as a fuel source for the microgrid, with the intention to convert the plant to gas over time. More generally, gas fired cogeneration is too often the fuel source of choice for microgrids, even if some amount of renewable input is fed into the microgrid in addition.

The outsized role for fossil fuels relative to renewables in some microgrids can be disguised by the nameplate capacity for each source. Since solar has a capacity factor of around 25 percent, when gas and solar have equal nameplate capacities in a hypothetical microgrid application, the microgrid will in fact run overwhelmingly on fossil fuels. Taking a light touch approach in the regulation of microgrids could counteract the statutory obligation the Commission has to uphold the District’s climate commitments.

For these reasons, the Sierra Club asks the Commission to adopt regulations in its microgrid framework that ensure that newly established microgrids in the District are powered overwhelmingly by renewable energy sources. This could allow a small role for gas-fired backup generators which run exclusively during resiliency events when the microgrid is truly needed.

It would be a grave mistake to locate new fossil fuel powered electricity generation sources in DC under the veil of advancing resiliency and microgrids.

Sincerely,

Matthias Paustian
Co-Chair, Beyond Gas Subcommittee