Thread by @JesseJenkins

Morning. The #TexasFreeze continues & grid operator ERCOT is still reporting >31,000 MW of thermal generation capacity out as of 9AM CT. Down slightly from a peak of 34,000 MW reported yesterday afternoon (ercot.com/news/releases/…) but still >40% of thermal capacity in state!

Wind power is currently producing about 4,000 MW, or 2/3 of the ~6,000 MW that ERCOT was counting on wind to contribute during winter peaking events. Solar is coming online now and helping during daytime, exceeding the <300 MW it is counted on for in system planning.

Main story continues to be the failure of thermal power plants -- natural gas, coal, and nuclear plants -- which ERCOT counts on to be there when needed. They've failed. Of about 70,000 MW of thermal plants in ERCOT, ~25-30,000 MW have been out since Sunday night. Huge problem.

ERCOT started directing electric utilities (like Oncor or Austin Electic) to start rolling blackouts or involuntary emergency load shedding at 1:25am on Monday morning, with 10,500 MW shed during that late morning. That's ~2 million homes worth of load ercot.com/news/releases/…

Throughout Monday, many thermal power plants remained offline, as freeze-offs + fuel shortages in gas pipelines forced large numbers of natural gas plants offline. Many coal plants likely struggled as well w/frozen coal piles, but breakdown of thermal outages by fuel type unclear

1 nuclear reactor at South Texas Station (STS-1) also failed yesterday, NRC data confirms. That's 1,280 MW of lost capacity also (en.wikipedia.org/wiki/South_Tex…)
nrc.gov/reading-rm/doc…

In short, ALL generation types are getting hammered.
This is an equal opportunity "clusterfuzzle" as @gmbutts put it. So put aside your technology favoratism and tech tribalism for today please!

In sheer numbers, natural gas-fired units are largest thermal capacity in Texas, accounting for ~56,000 MW or 66% of total capacity ERCOT was planning to have available during winter peaking events. The large majority of outages during this event are also at gas-fired plants.

This #TexasFreeze event is FAR outside what ERCOT planned for. Their 2020/2021 Winter Resource Adequacy Assessment estimated a worst case scenario "Extreme Pead Load/Extremee Generation Outages" scenario that included 13,953 MW of total thermal outages ⤵️

ercot.com/content/wcm/li…

So in sum, total thermal generation outages of 25,000-30,000+ MW during the past 36 hours are more than DOUBLE what ERCOT considered an "Extreme Generation Outages During Extreme Peak Load" event! That is where the disaster is stemming from. (Wind underperformance is secondary).

Additionall, ERCOT predicted a seasonal peak demand of 57,699 MW with a "Extreme Peak Load" scenario adding 9,509 MW to that, for a total "extreme" scenario of 67,208 MW.

Reality: On Sunday night, ERCOT recorded a new peak winter 69,150 Megawatts between 6 and 7 p.m on 2/14!

So what is leading to widespread and long-lasting electricity outages in Texas?

1. Total electricity demand was ~3,000 MW over the "Extreme Peak Load" scenario ERCOT planned for.
2. Thermal power plant outages were 10,000-16,000 MW over the "Extreme Generator Outages" scenario.

Those two factors together account for the entirety of the 10,500-16,500 MW of emergency load shedding -- aka rolling (or not so rolling) blackouts that ERCOT has reported over the past 36 hours (see ercot.com/news/releases/… and ercot.com/news/releases/…)

Those of you who have heard that frozen wind turbines are to blame for this, think again. The extreme demand and thermal power plant outages are the principle cause.

Wind & solar have variously over & under-performed the ~6,200 MW ERCOT was planning for from these resources.

At times, wind + solar output was ~4,000-5,000 MW below what ERCOT was counting on them form, and that certainly is part of the story, but much smaller than the total thermal capacity outages, and also less prolonged. Much of the past 36 hours, wind+solar has exceeded 6,200 MW.

Finally, note that in addition to widespread blackouts from major generation failures, there are also localized power outages from transmission & distribution failures affecting numerous customers. Downed lines, overloaded transformers, etc. Networks also fail in extreme weather.

That's a basic summary of what's going on right now. Conditions are still bad in Texas. Last night was frigid and I've seen many reports of interior temps reaching the 40s in people's homes. That's terrible and can be deadly. We don't know the full toll of this emergency yet.