Four Corners: a coal plant navigates the clean energy transition

Ten years ago, the Four Corners Power Plant was at a crossroads. The plant faced prohibitively expensive requirements to clean up its emissions. Environmentalists and regulators were concerned about haze at the Grand Canyon. The Navajo Nation had a significant economic engine and good-paying jobs on the line. And at APS, we were concerned about protecting affordability and reliability for our customers.

In collaboration with all stakeholders, we found a way to “cut the Gordian knot,” as an op-ed in The Arizona Republic put it in 2010. We closed three older units at the plant, expanded our ownership share of the newer, cleaner units and committed to add more pollution controls.

Those changes have had a clear result: cleaner air. Closing the older units reduced nitrous oxide (NOx) emissions by more than 90%. New pollution controls, known as selective catalytic reduction or SCRs, installed in the remaining two units in 2018 reduced their NOx emissions by 88%.

Employee stands outside at the Four Corners Power Plant with APS work truck driving by
The installation of pollution controls at Four Corners is part of our continued investment in a cleaner energy future. In fact, this year we announced our commitment to provide customers with 100% clean energy by 2050.

Our clean energy commitment includes ending all coal-fired generation by 2031. So why did we invest in pollution controls on a plant that will close by 2031? Because while we are moving away from plants like Four Corners, the truth is we still need them right now.

Consider the lessons of summer 2020, when the western United States experienced a severe regional heat wave. Some of our neighbors experienced rolling blackouts, but we kept lights on and ACs running for our customers on the hottest days. Four Corners played an important role in that reliability, delivering affordable power during hot summer evenings when customer demand peaks.

We are in the midst of a significant transition – a transition to clean energy – and we are committed to providing reliable, affordable service for our customers during this transition.

Four Corners won’t be a part of our energy mix 11 years from now. But we’ll depend on the plant in the intervening years to support reliability and affordability even as we invest in additional clean energy resources. And we’ll work with stakeholders like our partners on the Navajo Nation to manage the economic transition that accompanies this clean energy transition.

You can count on Four Corners to produce cleaner power on hot summer days until new solar plants, wind farms and energy storage solutions are in place to supply those megawatts our customers need to run their homes and businesses in 2031 – and beyond.

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