Winter Reliability, A Growing Not Passing Problem

The Power Line is a newsletter series that reviews key stories in the electric power sector—ranging from grid reliability, transmission issues, and emergent technology and business models. The Power Line will highlight the connections and relevance between the sector’s technical, local, and often esoteric stories to high-level public policy conversations on climate and energy taking place in Washington, D.C.

The nation’s electric power grids have emerged largely unscathed from a continent-spanning snap of cold weather and winter storms this winter. This outcome stands in stark contrast to previous bulk power system failures, with grid operators resorting to load shedding in December of 2021 during Winter Storm Uri and in February of 2022 during Winter Storm Elliot. Though this round avoided system failures, narrow margins of error were everywhere. Across the country winter reliability scares have now emerged as an annual tradition, one that bodes ill for the nation’s energy systems and the economic engine they power.

The ERCOT Case Study

Much of the attention was again on the Texas power system, known as ERCOT. As is now routine, a new peak demand record was set. January 16 recorded all-time high winter ERCOT demand of 78 gigawatts (GW), smashing through the previous record 74 GW set during Winter Storm Elliot roughly a year prior. Despite the strong demand, prices remained relatively tame and ERCOT was never forced into emergency procedures.

A key part of the success story is the torrential pace at which ERCOT interconnected new generation in the year between these peak demand records. U.S. Energy Information Administration data indicates that roughly 7.4 GW of new supply resources were interconnected in 2023, including 4.1 GW of solar and 1.3 GW of battery storage. ERCOT’s unique approach to the interconnection queue enables faster approval and connection of grid resources process than peer markets.

Remote Visualization

Another crucial piece of the story the is improved performance of the thermal generation fleet, that is gas, coal, nuclear fueled plants. Winter Storm Uri forced an incredible 31 GW of thermal generation offline, Winter Strom Elliot the next year saw 14 GW of thermal generation offline. Through the peak load period witnessed on January 16 and 17 of this year, ERCOT saw only 7 GW of such outages according to data from This improvement suggests that the weatherization campaign undertaken by ERCOT has yielded considerable resiliency benefits.

Near Misses Elsewhere

Two additional winter reliability highlights from the continent-spanning cold snap. First, in Washington state, an outage at a gas storage facility created risk of failure on a major interstate gas pipeline serving the pacific northwest. In the end, the storage facility was back online within the day, and worst-case scenarios in which numerous gas-fired power plants would be stranded unable to access fuel were avoided. But the near miss highlights how deeply entwined gas and electric system reliability is during winter weather.

Second, across the northern border, the Alberta energy market was forced to issue an emergency alert for voluntary load reductions and came very close to initiating load shedding. Alberta faced a specific weather pattern that drove all-time peak demand on the system and but kept wind and solar contributions to nearly 0 percent of total capacity. The system was almost entirely served by gas-fired power plants; any major interruption to fuel supplies akin to the Northwest Pipeline scenario above would’ve been catastrophic. It is no wonder that efforts are underway to explore diversification through nuclear power.

The Big-Picture Challenge

A problem emerging almost everywhere is the lack of diversity in dispatchable generation resources, a problem that will intensify as the remaining coal-fired generation fleet retires in the coming decades. Gas-fired power acts as a wonderfully effective balancing resource to wind and solar, but excessive reliance on it erodes this reliability benefit. Between a long-term inability to reform gas-electric coordination and the political difficulties associated with expanding natural gas fuel delivery systems, the gas-fired generation fleet has transformed into a central source of risk.

Partial mitigation is provided by rapidly increasing battery storage deployment. But battery storage largely plays a role on the margin, managing peaks and easing net load ramps. A look at the sheer volume of electricity produced by natural gas fired generation over the winter storm in ERCOT—representing just over 50 percent of generation—demonstrates how large a task it might be to displace balancing role of natural gas with battery storage alone.

Set against what is shaping up as a new era of rapid load growth, the status quo regulatory frameworks for the electric power sector are unsuitable. From here negative futures are possible. One such path is the stunting of load growth through a decentralized and largely unmonitored process of utilities across the nation declining new load interconnection requests. This result undercuts economic growth and opportunity, and importantly, undermines investments by the federal government into various strategic industries.

Alternatively, an era of load growth combined with an era of routine reliability scares and load-shedding events is possible. The costs of this path should not be underestimated. Beyond the obvious and dangerous effect on households suffering through winter storms in the dark, vast new implicit costs would be placed on businesses as they adapt operations and investments to electric unreliability. The downstream negative impact on U.S. economic vitality would be immense.

Both paths must absolutely be avoided. The way through is policy and regulatory frameworks that usher in an era of large-scale investment in the electric power sector to match the demand growth potential. On the supply side, new generation resources should be interconnected at a rapid pace; this should include new sources of dispatchable generation that dilutes the United States’ dangerous excessive reliance on gas-fired generation. New nuclear power fits the bill here, but federal policy is likely needed to catalyze the industry growth. And critically, no matter the mix of generation resources ultimately invested in, the transmission system will need to rapidly expand to cost-effectively deliver supply to demand.

What We’re Reading

Resurgent US electricity demand sparks power grid warnings, Financial Times

Europe’s under-the-radar industrial policy: intervention in electricity pricing, Bruegel

Year-end Reflections and Outlook on China's Power Sector, The Lantau Group

Cy McGeady is a fellow with the Energy Security and Climate Change Program at the Center for Strategic and International Studies in Washington, D.C.

Cy McGeady
Fellow, Energy Security and Climate Change Program