Earlier this week, we here in Texas went through a major cold snap, with state-wide rolling power outages and burst water pipes. A few died from cold or carbon monoxide poisoning. I was without power for about 2/3’s of the time Monday and Tuesday … which didn’t cause me any serious problems.
I’ve tracked down enough data to shed some light on the overload of the Texas power grid that forced shutting down a substantial part of the load (about a third of the state’s customers at any given time, from what I recall), in order to keep the remaining power plants from failing due to being overloaded.
From the U.S. Energy Information Administration (EIA) , between 2 AM and 3 AM Monday morning 15 Feb 2021, the following changes occurred in the amount of power provided to the Texas grid, from the following sources:
- Coal - dropped 1 GigaWattHours
- Natural Gas - dropped 7 GigaWattHours
- Nuclear - steady
- Wind - steady
Then over the next 12 to 15 hours, these further drops occurred:
- Coal - further dopped 2 GigaWattHours
- Natural Gas - further dropped 3 GigaWattHours
- Nuclear - dopped 1 GigaWattHours
- Wind - dropped 2 GigaWattHours
Finally, through evening of Monday, Wind dopped 2 more GigaWattHours, down to almost nothing.
The other power sources, hydro, “other”, and solar did not provide as much power as the above, at any point.
From something else I recall seeing a day or two ago - I have no link now - Texas electric was already running close to the edge - just enough power online to meet demand.
So the incoming cold spell, which would have increased demand for natural gas, both as the largest provider of electricity, and for heating, apparently lost some natural gas electricity providers (why?), caused an over load condition, which forced shutting down load. Too little power available trying to feed too high a load forces remaining providers to shut down hard and fast, to avoid major damage, so the load had to be dropped harder and faster.
… which they did … as reported in the following:
Texas’ power grid was “seconds and minutes” away from a catastrophic failure that could have left Texans in the dark for months, officials with the entity that operates the grid said Thursday.
As millions of customers throughout the state begin to have power restored after days of massive blackouts, officials with the Electric Reliability Council of Texas, or ERCOT, which operates the power grid that covers most of the state, said Texas was dangerously close to a worse-case scenario: uncontrolled blackouts across the state.
The quick decision that grid operators made in the early hours of Monday morning to begin what was intended to be rolling blackouts — but lasted days for millions of Texans — occurred because operators were seeing warning signs that massive amounts of energy supply was dropping off the grid.
As natural gas fired plants, utility scale wind power and coal plants tripped offline due to the extreme cold brought by the winter storm, the amount of power supplied to the grid to be distributed across the state fell rapidly. At the same time, demand was increasing as consumers and businesses turned up the heat and stayed inside to avoid the weather.
“It needed to be addressed immediately," said Bill Magness, president of ERCOT. “It was seconds and minutes [from possible failure] given the amount of generation that was coming off the system.”
Grid operators had to act quickly to cut the amount of power distributed, Magness said, because if they had waited, “then what happens in that next minute might be that three more [power generation] units come offline, and then you’re sunk.”
I agree with Martin Armstrong that this was a major, but not unnatural, weather event, experienced in both Central US, and at similar latitudes, down to Syria and Lebanon.
The critical initial point of failure seems to be a combination of:
a Texas electric grid whose spare capacity is more focused on summer heat than on winter cold,
running close to the edge as a big cold spell hit,
with an Achilles heal of its natural gas power plants, which
compete for natural gas with residential and (I presume) commercial heating.
At 2 AM Monday morning, Texas was getting 40 GigaWattHours of its total 60 GigaWattHour electrical demand from natural gas fired plants.
Over the next few hours, Texas lost 10 of those 40 GigaWattHours of electrical power coming from natural gas, with 7 of those lost 10 coming in the first hour.
Secondarily, over the rest of Monday,Texas also lost all 5 GigaWattHours (my above numbers only add to 4 …rounding errors) of its Wind power. I suppose that was just the typical calm winds as the cold, dry, air mass settled in.
Unknown, to me, at this time: What started those natural gas fired power plants to start going offline? I could speculate on possible causes, but I don’t have sufficient (in either quantity or quality) information to make a determination.