Xcel said that the proposals are in addition to projects which have already received regulatory approval and will cover operations in the US states of Minnesota, Wisconsin, North Dakota, South Dakota and Michigan.

The utility specifically highlighted the Sherco plant, a retired coal generation site which Xcel is replacing with a 710MW solar PV site. The new agreement plans to add a 300MW lithium-ion battery at the site.

Xcel will also extend the use of its two carbon-free nuclear plants at Prairie Island and Monticello through the early 2050s.

This agreement builds on the announcement of the plans in February this year when Xcel also announced plans for 2.2GW of “always available resources” to function as a backup to its expanded renewable energy portfolio. This has been replaced with more concrete plans for a hydrogen-capable natural gas-fired power plant in Lyon County, Minnesota.

Ryan Long, president of Xcel Energy—Minnesota, South Dakota and North Dakota, said: “This plan invests in innovation that maximises value for customers, creates jobs, and supports the communities we serve. We’re making great progress toward our vision for reliable, affordable, 100% carbon-free electricity, and we appreciate the support of our stakeholders on an agreement that allows us to keep building the clean energy economy of the future.”

A final decision on the agreement is expected in early 2025, until which point the public can make comments through the Minnesota Public Utilities Commission process.

The Midcontinent Independent Transmission System Operator (MISO) – the interconnection zone in which Xcel operates – has been slow on the uptake of solar PV in comparison to other independent system operators (ISO) in the US. Recently, following an uptick in announcements for solar projects in the region, PV Tech Premium looked into the growth of the technology across the MISO.