Storage and renewables projects already offered in response to an RFP from the Public Service Company of Colorado (PSCo) would be more economic and provide greater capacity than a 400 MW gas peaker unit proposed by the utility, found the consulting firm Strategen in an analysis of the utility’s proposed resource plan.

The Colorado utility, an Xcel Energy subsidiary, “takes commendable strides toward decarbonization,” says the Strategen analysis, but the low cost of clean energy resources supported by the Inflation Reduction Act “could provide an opportunity to avoid additional natural gas deployment.”

Strategen analyzed a portfolio of battery storage, solar and wind projects it selected from a public list of almost 800 bids for new renewables and battery projects that were offered in response to the utility’s 2022 all-source request for proposals.

Strategen said its portfolio, sized to exceed the capacity of a 400 MW gas peaker unit the utility proposed in its resource plan, would provide savings of about $29 million in its first year of operation, with greater savings in subsequent years. Those savings do not consider grid service benefits, stranded asset risk or fuel supply risk.

Because the costs for specific RFP bids are not publicly available, Strategen’s analysis assumed that the costs of the battery storage, solar and wind projects would equal the generic costs that PSCo presented in an appendix to its resource plan.

PSCo’s plan proposes 628 MW of new gas units by 2027, representing “long-term investments that will restrict PSCo’s ability to eventually achieve a fully decarbonized grid,” Strategen’s report says.

For two of the gas units proposed by PSCo—sized at 200 MW and 28 MW—Strategen was unable to analyze the potential to substitute renewables and storage because the utility proposed those units specifically for their local reliability benefits, and the public database of projects submitted in response to the RFP did not disclose location data. Strategen said its analysis of the 400 MW gas unit may also be applicable to the 200 MW unit if locational data and local reliability analysis were made available to stakeholders.

Strategen credited PSCo with proposing in its resource plan an 80% reduction in carbon emissions from 2005 levels by 2030, retiring all coal plants in the process.

Even so, Brian Turner, a director at the trade group Advanced Energy United, which sponsored the Strategen analysis, said Xcel’s proposal to build the new gas units “is a missed opportunity to provide Colorado households and businesses the best-cost and cleanest energy.” Turner noted that last winter the price of natural gas “skyrocketed, leaving ratepayers with high bills.”

Advanced Energy United said in a statement that as the cost of renewable energy continues to decline, new gas turbines risk becoming stranded assets, leaving ratepayers to pay billions of dollars “for a resource that may one day soon no longer produce any energy.”

The trade group formally presented its concerns in comments it submitted to the Colorado Public Utilities Commission.