This whole article seems light on nuance. The plant in question is a peaker plant. The entire point is to run it as little as practical. It's not being built to satisfy base load or to produce enormous amounts of total energy -- it's being build to supply capacity to the grid. Unlike solar or wind or even a battery system of any reasonable size, it can be run when needed and turned off when needed. It's entirely reasonable to build a sustainable grid based on lots of renewables and gas-fired peaker plants to keep everything working reliably under adverse conditions.

So surely the article should talk about the economics (to the grid operator and to the rate-payers) and how it, or a plant like it, affects the average emissions per unit energy supplied by the grid.

The next someone gets excited about installing a shiny new heat pump in a place that can get very cold (which includes parts of Arizona!), remember that its coefficient of performance can get quite low on a cold winter night, that it's really nice to keep one's house warm, that the sun won't be shining when this happens, and that the worst-case grid capacity has to come from somewhere. And, as some Texans can remind you, it really sucks when that energy fails to show up when needed. (Not to mention that parts of Arizona get very very hot and surprisingly humid, too, and the capaity needed for cooling and dehumidification on the worst days also has to come from somewhere.)

To be clear, I'm entirely in favor of calmly and carefully phasing out residential natural gas, but doing so is not at all a free lunch. In places where gas infrastructure already exists, and to the extent that leaks can be controlled adequately, an efficient, low-emission natural gas boiler/furnace is a very nice way to produce efficient heat in very cold weather, and it is just as efficient in very cold weather as it is in more mild weather. Unlike, say, a heat pump. Far too many people who want to phase natural gas out quickly don't consider the tradeoffs.