It’s 2018 and they’re bravely switching to *gas* to save the climate? That’s a bit of a reach.
You can't quickly turn off a coal plant when the Sun rises and then quickly turn it back on when the Sun sets. That makes it very difficult to replace a coal plant with a solar farm.
You can shut down a gas plant rapidly when the Sun rises and avoid hours of fossil fuel consumption.
Gradually we will install enough wind, solar, and short term (one to three) day storage to keep gas plants offline most of the time. A very few times per year we will hit a bad patch when we get too little generation from wind and solar to keep the grid going. Then we can use those (now paid off) gas plants to get us through the tight spot.
Eventually we should be able to dispense with natural gas totally. We might get the need for gas plant generation low enough to supply the fuel needs with biogas (compost and sewage). Or come up with some other solution which we haven't yet though up.