Sometimes to get what you want, all you have to do is ask. That’s what the organizations managing electricity grids across the country (and outside of it, but we’ll get to that) learned this week as plunging temperatures led to record-high electricity usage while lights (and heaters) stayed on.
One can get an eyeball sense of the effect these voluntary conservation notices have by looking at the difference between expected electricity demand versus what actually was needed this week. While some of this could just be normal forecasting errors, recent history suggests that big divergences during peak demand hours are likely the result of requests to use less power.
In contrast to past cold snaps such as Winter Storm Uri in 2021 and Winter Storm Elliott in 2022, utilities did not need to do any mass “load shedding” — i.e. rolling blackouts — in order to handle the high demand. During Uri, much of the Texas electricity system essentially failed for several days, leading to hundred of deaths, while during Elliott, the Tennessee Valley Authority instituted rolling blackouts for the first time ever as hundreds of thousands of Duke Energy customers in the Carolinas lost power.
This time around, TVA requested customers conserve power from 6 a.m. to 10 a.m. on Wednesday morning, citing extremely low temperatures throughout the Tennessee Valley and the areas it serves.
TVA was right that the grid would be stressed — it would ultimately break its all time record for demand. And yet, that demand peaked on Wednesday morning at 8 a.m. at 34,376 megawatts, notably short of the forecast demand of 35,125 MW, according to Energy Information Administration data.
There was also a sizable gap between forecast demand and actual demand the evening prior, after the TVA put out a release requesting conservation the following morning, but before the actual conservation period began. The request was tweeted out a little after 5 p.m. Central time on Tuesday; by 8 p.m., there was a roughly 3,000 MW gap between forecast demand and actual demand.
Something similar happened earlier this week in Texas. This time, ERCOT, which runs the market for 90% of the state’s electricity consumption, issued requests to conserve for Monday and Tuesday mornings. At 9 a.m. Central time on Monday, ERCOT forecasted demand of 83,561 MW, while actual demand was 74,452 MW. And on Tuesday morning at 8 a.m., forecasted demand was 87,055 MW, while actual demand was 78,155 MW. ERCOT’s all-time demand record from last summer still stands, but it broke winter records this week.
And in the U.K., the national grid operator has turned this into a business, paying homes and businesses some $11.4 million so far this winter to conserve demand in peak moments, according to Bloomberg. The combined energy saving was enough to power six million homes for at least an hour, per the report.
Voluntary conservation calls, while often effective in the short term, are often an indication that something has probably gone wrong. In both Texas and the TVA territory, advocates have called for measures to make grids more resilient and to improve energy efficiency, especially during cold weather. This means everything from winterizing natural gas infrastructure to updating building codes to better insulating homes so that they require less heat during cold snaps.
There are also more structured ways to get customers to consume less electricity during peak demand times than putting out voluntary requests — so-called “demand response” includes systems of incentives and payments to use less electricity at peak times. But Texas does not, as yet, offer them at a meaningful scale to residential customers, just businesses.
