I draw a completely different answer than them from the same data. Which is an interesting position to be in. For those who didn't read the article, the contention is that phasing out thermal generation (coal and natural gas) will lead to grid instability, particularly in cold weather. The argument is that wind tends not to blow in Washington when it's cold, so there's a higher risk of brownouts especially as demand increases. The power demand curve has been flat for the last couple of decades due to efficiency increases, but is expected to increase by up to 50% in the foreseeable future. That all sounds pretty dire, especially when thermal is around 5%-10% of the power generated in our state.
Where I disagree is actually cited in another Forbes article that complains about new wind turbines in SW WA, linked
here. This is a graph of Bonneville Power Administration (BPA) generation in a period in January 2014. I don't really know if this was a particularly cold snap or not, so I don't know where the demand curve hits relative to maximum. For reference, BPA is the major operator of the federal hydropower dams on the Columbia/Snake system, and is a major electrical power broker. Some cities/utility districts have their own power systems which may or may not be part of the BPA totals listed here.
Red is demand, blue is hydro generation, brown is thermal, and green is wind. Solar presumably isn't enough to show up on the graph, which makes sense in our dark winter. What leaps out at me here is that demand peaks at 8 GW and hydro generation peaks just shy of 12 GW. Even on the first two days when the wind isn't blowing, there's plenty of hydropower available to cover even a 50% increase in demand. In addition, per this
fact sheet, BPA's total hydro generating capacity is 35 GW. The wind turbines get dinged for operating at 30% capacity in the article you linked, but it turns out that dams are operating at less than that. There's also been a few times recently where wind turbines were told to shut down so that they could generate more power through hydro.
The last bit of local knowledge is that the depths of winter is the rainy season. That's when our reservoirs are full and spilling water just to keep from overtopping. If there's a very cold low-wind day, then spool up the dams a bit and refill the reservoirs in the rainstorm that's less than a week away.
There may be an issue in the summer, when hydro turns down a little bit to save water for salmon and there's increased demand from air conditioning. However, solar really shines then when we have 16-hour days. There's also a large temperature differential between Western and Eastern Washington, which creates a lot of wind across the Cascade crest and through the Columbia River Gorge. Unsurprisingly, the major wind farms are placed to take advantage of that wind resource. If you want to look up a similar graph to the one above for a summer week, I'll be glad to discuss it.
Finally, I'm not an energy economist, so I may be missing parts of the picture.
