Update: ERCOT lifted the emergency declaration at 6 p.m., but urged consumers to reduce electricity use during peak electricity hours from 3 to 7 p.m. for the remainder of the week.
Texas’ grid operator declared a Level 1 Energy Emergency Tuesday afternoon as record heat across the state led to the second consecutive day of record power use.
Power demand topped out at 67,929 megawatts at 5 p.m. Tuesday, beating Monday’s all-time record of 66,867 megawatts. The prior record, 65,776 MW, was set on Aug. 23, 2010.
The Electric Reliability Council of Texas, which oversees the electric grid for about 85 percent of the state, warned Monday of high power demand for the entire week.
But around 2:40 p.m. Tuesday ERCOT activated the first of a four-stage power warning system when surging demand sent power reserves below a key safety margin.
ERCOT called on consumers to conserve power, began bringing online all available power plants and tapping neighboring power grids, including about 130 megawatts from Mexico.
About 20 power plants with 3,000 megawatts of capacity were offline Tuesday due to unplanned outages, but Kent Saathoff, ERCOT’s vice president of system planning and operations, said that wasn’t unusual for a typical summer day.
One megawatt of power is enough electricity to power about 200 homes in Texas during hot weather when air conditioners are running for long periods of time.
It’s not clear if consumers responded to the call for conservation, Saathoff said.
“But we certainly hope so,” he said.
Saathoff said the state could continue to break demand records throughout the week, although thunderstorms or additional cloud cover could greatly reduce power demand in some areas.
“We’re concerned particularly for the rest of this week as temperatures are forecast to be at about the same levels,” he said.
Saathoff said about 1,800 megawatts of wind power was on the grid Tuesday, more than the 800 or so megawatts typically scheduled.
Tuesday’s emergency was the lowest in ERCOTs warning system, a Level 1. It is called if reserves drop below 2,300 megawatts.
A Level 2A emergency is declared if reserves drop below 1,750 megawatts. At that time industrial customers who have agreed previously to shut-down equipment in an emergency would be called on. That would relieve the system of about 1,000 megawatts of demand.
At Level 2B, when reserves are continuing to drop, another group of commercial customers would be called on to cut off their power use. That group accounts for about 300 megawatts of demand.
A Level 3 emergency is called when the outages begin to threaten the integrity of the entire grid. At that point local utilities — such as CenterPoint Energy in the Houston area — would be called on to do rotating blackouts, where certain circuits are cut off for 15 to 45 minutes — or longer — at a time.
Rolling blackouts are rare. ERCOT called for them in February when a sustained cold snap led to the failure of dozens of power plants.
Rolling blackouts were also used in 2006 to avoid deeper problems with an unseasonably warm spring day coincided with a number of power plants outages for maintenance work.
ERCOT asked for conservation on Monday but didn’t have to take any emergency steps, such as drawing on power from neighboring grids or asking pre-selected industrial customers to shut down.
But judging from some reader comments on Monday afternoon, one might have thought ERCOT had put out a call for our first-born children:
“We are now living in a 3rd world country,” said ‘Luckyone.’ “I’ve lived in Texas all my life, and I don’t remember this happening before. It must be a result of Hope & Change.”
Luckyone must have been out of state temporarily during our Spring 2006 rolling blackouts and the many other conservation warnings we’ve had in summer’s past.
“NO!” shouted ‘Ed C.’ “What part of that do you not understand? I will now go cut my thermostat down and run my dryer just because you told me not too. Fix the PROBLEM liberal democrats! Get off your rear and do something about it!”
Since ERCOT didn’t need to take any real emergency measures Monday, should they have just said nothing to avoid sending people into a tizzy?
One argument is that if they didn’t warn us and there was a real emergency, ERCOT would likely face a whole lot of scrutiny from lawmakers and from the Texas Public Utility Commission.
But one reader — ‘GAPlatt’ — mentions a reason why ERCOT’s current approach to times of high power demand may not be the best.
In a nutshell, ERCOT is too quick to bring online spinning reserves — power units that are on contract for the day to fire up within 30 minutes to relieve a crunch. By bringing online these back-up units, ERCOT actually drives down the spot power prices that usually rise when there’s a shortage.
That may sound great for electric retailers and consumers — price spikes are flattened before they get too sharp.
But it also removes a price incentive that encourages companies to build power plants in Texas. It’s an issue Chron business columnist Loren Steffy wrote about earlier this summer.
That’s not to say Texas is short on power plants right now. We actually have plenty of units that are on the books as ready to operate to meet our needs (despite readers insisting they’ve been shut down by environmentalists).
Rather it’s a question of whether companies will keep building them in the future, to replace the older plants.