Y’all, it’s f’n cold here.

This chart is the whole story and it is not good for anyone.

Look at Feb 5 or Feb 9. Sometimes wind goes to zero or near zero. It's ok - that's what wind does. The grid didn't collapse. Sometimes, like Feb 8, wind blows a lot - enough to push some coal offline (see the dip in brown)? Again, that's ok, that's what it is designed to do.  Feb 9 we had more thermal on the grid than Feb 16. That is a complete breakdown - of the system. 

The problem is people see documents that ERCOT puts out which are kind of marketing that say "oh 23% of our capacity is wind, aren't we great?"

But wind capacity and thermal capacity are fundamentally different. One is dispatchable and the other one isn't.

There is a term called capacity factor which is the ratio of the asset's use to its theoretical maximum output. So if you have a power plant that runs every hour of the year at max power, it has a capacity factor of 1. If it runs every hour at half power, or half the time at full power, its 50%. Because wind is variable you expect an average capacity factor of around 35%, but that's just an average. Sometimes it is zero, sometimes it is 50%. Wind in Texas blows more at night and in summer. We planned for roughly a 20% peak average capacity factor for wind over the winter.

Maximum capacity factor for a base load (always on) gas turbine is around 92%. Actual capacity factors for combined cycle gas turbine plants are around 50% in the US, and peaking or simple cycle are 10-15%. This isn't bad, this is just what we need from them. Think about the capacity factor for your car engine - it is probably very low, you rarely run it at full power, and don't often drive it for many hours a day. That's fine.

How about my little backup / tailgating generator? Capacity factor is probably 1%. That's ok. It is doing exactly what I need.

The flip side to capacity, as I said, is dispatchability. That is being able to turn it on and off. If wind doesn't blow at any particular moment, it's fine. We don't expect it to, we don't plan on it, we don't count on it. If I go outside and my Honda generator won't start even once it is worse than useless. I will be cussing and kicking it and wishing hell and damnation upon it. It is supposed to be dispatchable that 1% of the time.

The difference between expectation and reality is reliability. Wind is VERY reliable. We forecast wind for seasonal average and detailed forecasts out 48 and 24 hours in advance. Our forecasts are really good, and in fact wind has outperformed installed expectations for capacity factor in Texas consistently. Remember we planned for a seasonal peak average of 6.2GW. Even with the cold and turbines offline in the peak event Sunday night wind was putting 9GW onto the grid. That is reliable, it exceeded our expectation by almost 50%. That's great.

Reliability and dispatchability are NOT the same thing. My Honda generator is both dispatchable and reliable. I can turn it on whenever I want, and it literally has never failed me. I love it. My lawnmower is dispatchable but not reliable. And I hate it for that reason. Wind is reliable but not dispatchable. 

Gas, coal, and nuclear are dispatchable and generally very, very reliable. But we lost 25% of our nuclear output. Less reliable. We lost ??% of our coal plants. Less reliable. We couldn't run due to gas or lost some 30% of our gas capacity. Less reliable. Still dispatchable! There's an on switch! But not doing what we planned...counted...relied on.

It's not a failure of the wind technology that it is not dispatchable. It is not a failure of gas technology that it was not reliable - or coal, or nuclear. This is a compound problem in Texas. Gas wells froze, gas liquid separation plants froze or were shut off, pipelines had problems, there may have not been enough gas period due to incredible demand for heating and electricity production, and of course coal plants had problems offloading traincars of coal, sensing lines freeze, its just a huge mess. Up north yankees deal with this all the time and their plants are designed differently for it. 

ERCOT has the lowest retail electric prices in the world and our system is ingenious. It works really, really well. Part of that is due to the limited amount of backup capacity we carry. That's the definition of a wasted asset - if it doesn't run, it just costs. Well, we got bit. The real question is how much more expensive would everyone have been happy with their bills to ensure we didn't have this problem? Because it's not a question of feasibility, just of cost. We could have a grid with 150GW of power instead of 82GW and this wouldn't have been a blip. And my summertime electric bill would be $300 instead of $150, every single year, forever.

LOTS of political propaganda being put out there on both sides. Meanwhile people are suffering. Its sick.