California, Texas, May Face Grid Challenges this Summer

June 8, 2021

As summer approaches, the US Southwest is already in the grips of historic drought, with fire season impending, and reservoirs at record lows.
The Texas power grid debacle of last winter showed us how vulnerable the society is when power generators don’t, or can’t show up. With some hydro resources potentially compromised as a result of drought, and the prospect of record heat and fire, it’s hard to overstate how concerning this season’s set-up is.

Meanwhile, Texas’ grid, ERCOT, is configured, we’re told, to ride thru the worst heat waves the state can offer, but again, winter showed that climate change can bring conditions that are beyond business as usual. The Texas legislature, while mandating some weatherization of power plants, may not have taken adequate measures to address the challenges to ERCOT.

Canary Media:

California may be able to get through the coming summer without facing a repeat of last August’s rolling blackouts — if the weather cooperates.

But if the state faces another regionwide heatwave, it will need to rely on gigawatt-hours’ worth of newly installed batteries, a smaller but significant amount of extra natural-gas-fired power plant capacity, and a bigger commitment from customers to curtail electricity use during peak evening hours to ride through the emergency.

This snapshot of summer grid readiness has emerged over the past two weeks from the state agencies tasked with avoiding another round of forced outages like those that left hundreds of thousands of Californians without power during the sweltering evenings of August 14 and 15 last year.

Last week, state grid operator CAISO released a summer reliability assessment that highlighted progress in adding more capacity to the grid, adopting energy market reforms and preparing a combination of emergency conservation measures like those that spared the state from even more outages in August and September.

Because of those steps, the grid operator is “cautiously optimistic that there will be enough electricity to meet demand this summer,” CAISO CEO Elliot Mainzer said in a statement last week. Still, natural threats exacerbated by climate change could overwhelm these preparations, he warned.

Those threats include wildfires that could force the outages of transmission lines carrying power into the state, as well as drought conditions that have left large reservoirs in California this year at 70 percent of normal levels, sapping in-state hydropower capacity.

Most critically, regionwide heat waves like those that struck the Western U.S. last August and September could threaten to once again constrain the out-of-state electricity imports that California relies on, as neighboring grids tap those resources to meet their own peak needs.

“We are in better shape this year than we were in 2020,” said Ed Randolph, deputy executive director for energy and climate policy at the California Public Utilities Commission, during a May 4 briefing on the state’s summer preparations. “However, if there is a repeat of extreme weather events, especially a heat event [that affects the entire Western U.S.], there will still be reliance on contingency measures.”

CAISO (California Independent System Operator):

Hydro Conditions

California hydro energy supply will be significantly lower than normal during 2021. California is in a second consecutive year of below normal precipitation statewide. Snow water content for 2021 peaked at 60 percent of normal, similar to the 63 percent level for 2020.

However, to date, 2021 runoff from snowmelt has occurred earlier than in 2020, which was earlier than normal itself, and the average water levels of large reservoirs for 2021 was 70 percent of normal, which compared to 101 percent of normal in 2020. The ISO used Northwest River Forecast Center projections as an indication of potential imports into California from the Northwest, and The Dalles Dam on the Columbia River is generally used as a representative indicator. The current April to September reservoir storage projection at The Dalles Dam Columbia River is 89 percent of average.

Peak Demand Forecast

The ISO 2021 1-in-2 peak demand forecast5 is 45,837 MW, which is 0.2 percent above the 2020 weather normalized peak demand of 45,742 MW.6 A comparison of the ISO 2021 weather driven peak demand forecast levels to those for 2020 are shown in Table 1. The 1- in-2 and 1-in-5 forecast levels are virtually unchanged for 2021, however the 1-in-10 forecast is significantly higher than the 2020 forecast. The higher loads associated with a 1-in-10 weather event are attributable to including last year’s extreme weather events in the historical weather database that is used to develop the range of load forecasts. This changed the high temperature end of the weather distribution profile such that the probability of the historical extreme heat events are now within the range of a 1-in-10 weather event. The ISO 2021 1-in-10 peak demand forecast is 50,968 MW – 11 percent higher than the 1- in-2 forecast level, a significant increase from the 6 percent incrementally higher demand of the 2020 1-in-10 demand forecast over the 2020 1-in-2 forecast.


Texas state lawmakers had just started a legislative session when deadly blackoutsgripped the state in February. The timing was fortunate. In Texas, legislators typically meet only once every two years. The fact that they were already in Austin meant they could act quickly, and many vowed to shore up the state’s electric grid and create safeguards against future power outages.

This week lawmakers approved a sweeping package of measures to address specific problems that threaten electric reliability — some of them despite opposition from the oil and gas industry. But many electric grid specialists, policy analysts and state politicians themselves said they’ve failed to do enough to prevent another blackout disaster. 

After a decade of warnings, a weak mandate to “winterize”

Ever since another major freeze and blackout 10 years ago, experts have said Texas needed to “winterize” or “weatherize” not only its power plants but its oil and gas infrastructure as well. The reason is that cold weather can freeze wellheads and other components in the natural gas supply chain, stopping gas from getting to power plants.

That weatherization part of Senate Bill 3 allows regulators to determine which parts of the natural gas supply chain are critical to electricity production and then requires that they be protected from the cold.

Most agree it is progress. But it only applies to equipment linked directly to power plants. Experts said it ignores the interconnectedness of the gas infrastructure.

“What I fear, that it’s just not going to be enough,” said Dan Cohan, a professor of civil engineering at Rice University. 

He said if there’s another big freeze, “whoever has those direct lines into the power plants and winterizes those is going to point upstream and say, ‘Well, those upstream people couldn’t get us enough gas.’ So yeah, it’s hard to see how this is going to provide us full coverage.”

The law also includes penalties as low as $5,000 a day for companies that do not winterize. Critics said those fines could cost less than the price of complying with the law.

Doug Lewin, president of the consulting firm Stoic Climate and Energy, said that “$5,000 for a big oil and gas company, to say it’s a rounding error is probably an overstatement.” 

After the blackout, analysts at the Federal Reserve Bank of Dallas said one simple way to build resilience into the natural gas supply chain would be to mandate weatherization of new gas wells built in Texas.

Lewin points out that the state Legislature failed to act on that recommendation.

Texas Tribune:

Electricity outages in Texas could occur again this summer — just a few months after the devastating winter storm that left millions of Texans without power for days — if the state experiences a severe heat wave or drought combined with high demand for power, according to recent assessments by the state’s grid operator.

Experts and company executives are warning that the power grid that covers most of the state is at risk of another crisis this summer, when demand for electricity typically peaks as homes and businesses crank up air conditioning to ride out the Texas heat. Texas is likely to see a hotter and drier summer than normal this year, according to an April climate outlook from the National Oceanic and Atmospheric Administration, and 2021 is very likely to rank among the 10 warmest years on record globally.

“This summer, I am as worried right now [about the grid] as I was coming into this winter,” said Curt Morgan, CEO of Vistra Corp., an Irving-based power company. “Sounds like I’m the boy that cries wolf, but I’m not. I’ve seen this stuff repeat itself. We can have the same event happen if we don’t fix this.”

As state lawmakers continue debating how to improve the grid after February’s storm nearly caused its collapse, on Tuesday Texans were asked to conserve electricity because the supply of power could barely keep up with demand. A significant chunk of the grid’s power plants were offline due to maintenance this week, some a result of damage from the winter storm.

The warning triggered a torrent of outrage from residents and political leaders across the state who questioned why the Electric Reliability Council of Texas, which manages the grid, allowed it to come so close to emergency conditions on a relatively mild spring day. “I appreciate the increased effort toward transparency, but wow this is nervewracking to see in April,” state Rep. Erin Zwiener, D-Driftwood, tweetedTuesday.

Heading into the summer, ERCOT included three extreme scenarios in a preliminary assessment of the state’s power resources for the summer — the most extreme calculations ERCOT has ever considered for the seasonal assessment. Each scenario would leave the grid short a significant amount of power, which would trigger outages to residents:

  • In the first scenario, a drought similar to what the state saw in 2011, combined with low winds, several natural gas plants offline and an increase in economic activity as the pandemic eases, would leave the power grid short 3,600 megawatts, or enough to power 720,000 homes.
  • Add low solar power generation to the first projection (say it’s a cloudy day), and the grid would be short 7,500 megawatts, or enough to power 1.5 million homes.
  • In the most extreme scenario ERCOT considered, a severe heat wave across the entire state combined with outages for every major power source would leave the grid short 14,000 megawatts, or enough to power 2.8 million homes.

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