The current debate in the U.S. electricity sector pitting efforts to increase renewables against the need for grid reliability in the face of growing demand could be unnecessary and counterproductive, according to Ric O’Connell, executive director of the nonprofit GridLab.
Faced with ever-escalating forecasts of demand growth from data centers, “a lot of utilities and grid operators and their regulators are getting a little nervous … that we’re not going to be able to have adequate resources to meet this growing load,” O’Connell said.
“I actually don’t think that concern is valid. I think we can do both. … We can both grow the clean energy percentage of our electricity and grow the amount of load that we need to meet certain demand,” he said.
Speaking at a March 26 webinar hosted by the nonprofit Energy Innovation Policy and Technology, O’Connell cited real-world, real-time examples to support his argument.
Texas now leads the U.S. in terms of total generating capacity, growing 36% over the past decade, while also doubling its share of renewables from 23 to 42%, he said. During times of peak production, carbon-free resources may provide more than 80% of the state’s power.
ERCOT’s online dashboard, tracking energy supply and demand across the Texas grid, showed solar, wind and nuclear making up about half of its generation mix March 27.
SPP ran about 47% on carbon-free generation in 2024, with wind power across the region at times providing 90% of the RTO’s power, O’Connell added.
Such comments, from O’Connell and other speakers, were aimed at fleshing out Energy Innovation’s recent report, “Grid Reliability in the Clean Energy Transition,” which argues for a more expansive, system-level approach to reliability. (See Energy Innovation: US Needs New Approach to Grid Reliability.)
“Reliability is thrown out a lot, and not always accurately or correctly,” said Sara Baldwin, Energy Innovation’s senior director of electrification policy and co-author of the report. “Reliability is actually a characteristic of the entire electricity system, and individual resources contribute to reliability as part of a balanced portfolio. …
“So, whenever you hear someone talking about the reliability of a single resource, that should raise a flag.”
The Energy Innovation report defines reliability as a combination of three core components: resource adequacy (long-range planning for future demand), operational reliability (day-to-day, real-time balancing of supply and demand) and resilience (the ability to ride out and recover from extreme events).
The traditional arguments raised against renewables are that they are intermittent and therefore cannot provide the 24/7 reliability and grid support services of coal, natural gas or nuclear power. But according to Julia Matevosyan, associate director and chief engineer at the Energy Systems Integration Group, technology is available to allow solar, wind and storage to provide a full range of grid support services, through the inverters that convert the DC power from solar panels and wind turbines into the AC power the grid uses.
The capabilities of these inverter-based resources have evolved as the percentage of renewables on the grid has increased, said Matevosyan, who previously worked as the lead planning engineer at ERCOT. For example, as renewables hit 10 to 20% of generation, inverters had to be set to ensure a solar or wind project could stay online and in operation in the event of a brief disturbance on the grid.
As renewables start to replace coal or natural gas, their inverters have to be able to provide voltage and frequency support, she said. At even higher levels, up to 75%, inverter-based resources can provide “essential reliability services,” with “grid-forming” technologies, which are “advanced controls … [that] can provide the suite of reliability services that synchronous generators are providing today,” Matevosyan said. “With that technology, you can potentially go to 100%” renewables.”
Grid-forming technologies have been demonstrated on small islands and in “large-scale system studies,” she said. “So, from the technology perspective, what I want to say is, just as the grid evolves and we define what the grid needs ― we define it in technology-neutral terms ― technology will step up and provide.”
Clean, Firm Emerging
But the Energy Innovation report also acknowledges that a significant gap exists between IBRs’ technical capabilities and industry confidence in their ability to deliver when needed in real life.
“Developers must be disciplined to program their resources to ride through a voltage event [even] if such a setting should compromise their asset or their operating revenues,” the report says. Similarly, utilities and grid operators need to “quantify and understand how IBRs respond during a grid emergency” and ensure appropriate compensation in cases where they “provide a superior response.”
At present, utilities, grid operators and the Trump administration are looking to natural gas and nuclear to respond to what they see as a looming reliability crisis, while characterizing renewables as intermittent and unreliable.
In his opening remarks at a March 25 congressional hearing on grid reliability, Rep. Bob Latta (R-Ohio) said EPA regulations limiting emissions from power plants were driving early retirements of dispatchable baseload power.
“Significant subsidies for intermittent generation undermine the economics of baseload, or on-demand, dispatchable generation resources that are essential to keeping the lights on,” Latta said.
Speakers at the Energy Innovation webinar offered two potential low- or no-carbon solutions.
First, demand-side management can provide varied options for improving grid reliability, O’Connell said.
“We don’t want to just focus on the supply side. … It used to be hard to sort of have load that was responsive to price or other kinds of signals, but now we’ve got smart thermostats; we’ve got customer-sited batteries; we’ve got EV charging,” he said. “Really, this is a load that can be controlled and respond to market signals. This is a really important way that we’re going to be able to meet our reliability [needs].”
Wilson Ricks, a doctoral researcher at Princeton University, pointed to the second solution: emerging clean, firm technologies, including long-duration energy storage, next-generation nuclear and geothermal, and fossil fuel generation with carbon capture and storage.
Rising amounts of renewables on the system are flipping seasonal demand peaks from hot summer afternoons, when renewables tend to be plentiful, to winter mornings, when they are not. “Current batteries are not necessarily a cost-effective solution to very long periods of low wind and solar output,” Ricks said.
“There’s a whole suite of emerging technologies that are designed to help fill these very rare but important gaps and ensure a 100% reliable, clean system,” he said.
The catch, Ricks said, is that all the promising technologies are still in early stages of development and commercialization and are very expensive. Demonstration projects are in the works, he said, but “ensuring the success of at least some of these projects is going to be crucial to ensuring the availability of a portfolio of clean firm resources that we’re going to need for 100% reliability.”
Getting clean, firm generation to commercial scale could also change the role of always-on baseload power as a foundation of reliability. While it will always be needed and valuable in some circumstances, “baseload has not been a panacea in the past,” Ricks said. “It’s only one portion of our grid. We still have fluctuating demand, and baseload generators don’t meet that. It’s certainly not the end-all, be-all of reliability going forward.”