Distributed Energy Resources

Battery storage is big part of Colo. utility’s plan

Xcel Energy subsidiary Public Service Company of Colorado has filed an energy plan with the Colorado Public Utilities Commission that calls for a shift away from coal-fired generation and toward more reliance on renewable resources.

Under the plan, PS Colorado would derive nearly 55% of its electrical supplies from renewable sources by 2026, driven by the addition of 1,100 MW of new wind power resources and 700 MW of solar generation.

The Clean Energy Plan also calls for the addition of 275 MW of battery storage that would be combined with solar power projects.

The plan also lists the purchase of two existing natural gas-fired plants as part of its preferred portfolio. The purchase has not yet been approved by the PUC, so PS Colorado cannot disclose the names of the facilities, but one is in Boulder County and is for 82 MW; the other is in Morgan County and is for 301 MW. Pending approvals, the acquisitions are proposed to be completed by May 2022.

The plan also calls for PS Colorado to accelerate the retirement of two units totaling 660 MW at its 3-unit Comanche coal-fired plant in Pueblo. Under PS Colorado’s preferred Clean Energy Plan, those units would retire in 2022 and 2025, compared with 2033 and 2035 under the business as usual plan detailed in the utility’s report to the PUC.

Compared with 2005 levels, the preferred Clean Energy Plan would, by 2026, result in a 60% reduction in carbon dioxide emissions and 90% reductions in sulfur dioxide and nitrogen oxide emissions.

The utility also says the preferred Clean Energy Plan would result in customer savings of more than $215 million relative to the business as usual plan, and calls that figure “conservative,” adding that there are “additional opportunities that could drive further savings for customers.”

PS Colorado also says its preferred plan would promote $2.5 billion in statewide generation investment spread across eight Colorado counties. The plan calls for new wind resources in the northern and eastern part of the state and over 500 MW of new solar and 225 MW of battery storage resources in the southern half of the state.

PS Colorado says that while the economic benefits of both its business as usual plan and the Clean Energy Plan are “reasonable, the compelling aspect of the Preferred CEPP is that it delivers lower costs with substantial environmental and renewable energy gains that are greater than in the traditional” business as usual plan.

The preferred plan also allows PS Colorado to own 27% of the renewable resources (500 MW of wind) and 58% of dispatchable and semi-dispatchable resources (380 MW of gas generation).

PS Colorado said it is willing to take a lower stake in owning generation resources in order to accomplish a more rapid transition to clean energy.

PS Colorado says its plan incorporates the input of a diverse group of stakeholders that supported the Colorado Energy Plan stipulation filed with the PUC in August 2017. The report filed with the PUC includes detailed analysis of more than 400 bids received in a competitive solicitation.

The plan filed with the PUC is the latest version of the utility’s 2016 Electric Resource Plan, originally filed with the PUC in May 2016. The PUC is expected to rule on the plan by September 2018.