Public Service Company of New Mexico (PNM) is seeking proposals for 456MW of generation capacity with emphasis on renewables and battery-storage options as it moves to end dependence on coal as an energy source.

Developers of those and other technologies must submit a notice of intent to bid by 30 November and any firm supply proposals by 30 January 2018.

The state’s largest electric utility would like to contract more wind energy as new transmission projects alleviate capacity constraints that have prevented projects from advancing in eastern New Mexico.

Developer Lucky Corridor, for example, is moving ahead with two projects designed to carry about 1GW of wind and other energy to connections with the Four Corners NYMEX Hub.

PNM now depends on coal for 56.1% of its energy mix. Officials there believe tougher federal environmental regulations are likely after President Donald Trump leaves office in either 2020 or 2024.

Switching to cleaner renewable energy and natural gas generators will provide more operational flexibility and save its half million customers money in the long-term, they believe.

PNM plans to permanently close two units at the coal-fired 1.85GW San Juan Generating Station in northwestern New Mexico this quarter to bring it into compliance with federal regulations aimed at curbing haze-producing pollution in the region.

PNM, which owns 66.4% of the facility, would like to close the remaining two units in 2022 when its partnership arrangement expires with minority stakeholders Los Alamos County, City of Farmington, New Mexico, Tucson Electric Power and Utah Associated Municipal Power Systems.

The four units came into operation in 1973, 1976, 1979 and 1982, respectively. Closing two of the units this year will reduce PNM’s reliance on coal to about 40%.

The utility also utilizes nuclear for 21.8% of its energy mix, natural gas 12.3%, wind 7.1%, solar 2.5%, and geothermal and other sources for the balance.

PNM also wants to end its involvement with the Four Corners Generating Station located on land leased from the Navajo Nation in the northwest corner of New Mexico. It owns 13% of Units 4 and 5 – each having 770MW of nameplate generating capacity.

This would occur in 2031 when its coal supply contract there expires. PNM would then be free of coal in its energy portfolio.