How Solar Will Keep the ACs Humming This Summer: Key Takeaways from NERC’s Summer Assessment

North America’s electricity grid watchdog is out with its summer assessment, and what it shows is that the reliability outlook for the grid is improving, in large part because of surging solar and battery power. While the Trump administration has been wasting time and money to prop up old, dirty coal plants, what this report shows is that new, clean energy is the key to keeping the lights on and air conditioners humming.  

The outlook from the North American Electric Reliability Corporation (NERC) is an important milestone, and it’s set to be incorporated into the Federal Energy Regulatory Commission’s (FERC) policy and planning. Here are some key components to keep in mind:  

1. Of the 16 grid regions in the United States, only two face higher-than-normal risk, along with a small part of Texas

   This is a significant improvement from previous years. Last year, the entire middle of the country, from Texas to North Dakota, was at risk of blackouts. While NERC had previously warned of the risks of the retirement of old coal plants, this year, it noted that new electricity supply exceeded electricity demand—and the largest source of new electricity is solar energy.  

2. Extreme heat, drought, and wildfires are having an impact on reliability

   While the Trump administration is busy dismissing climate change, the meteorologists (and engineers) at NERC know which way the climate is changing. The report says that in the Northwest: “Wide-area heat events, wildfires, and low snow-water equivalents due to a changing climate impact generation resource and transmission availability and remain a continued reliability concern.” And, it added: “Early summer heat and drought conditions will increase reliability risks across several regions.” 

   • There is real tension here, as NERC had previously warned about the retirement of old coal and gas plants, but emissions from those plants are causing the climate crisis that NERC is warning is a threat. 
   • Relatedly, the heat in March, which NERC noted was the hottest in 132 years of recordkeeping in the United States, cut into the typical shoulder season that power plant owners use to do their regular maintenance of those plants, which means those plants may be at greater risk of being out of service in early summer.   

3. Reliability risks are down, in large part because of record growth in generation—with solar and batteries being the fastest source of new power, and they are having a real benefit on costs and reliability

   “The addition of solar and batteries, which perform well under more hours of the day during summer than they do in winter, is helping to meet escalating demand and increase reserves in many assessment areas.” It’s worth noting that according to FERC, solar, wind, and batteries made up 80 percent of the new electricity added to the grid last year and are forecast to exceed that this year, according to the U.S. Energy Information Administration.  

4. Data centers are both driving electricity demand and being a key source of grid instability

   Data centers can cut out in unpredictable ways, putting the grid at risk by taking a city’s worth of electricity offline without any warning.  

   • Data centers can put the grid out of whack with unexpected disconnections. Grid operators need to prepare for how this could cause wider outages during summer, NERC said. For more on this, see NERC’s recent Level 3 Alert. 
   • Large loads such as data centers are coming online at a slower-than-expected pace, resulting in lower-than-expected demand forecasts. 
   • But in certain circumstances, data centers can be flexible. NERC points out that a lower demand forecast in Texas is the result of data centers not drawing from the grid during times of peak demand.  
   • Batteries can help mitigate this risk: Batteries are helping to “maintain stable frequency on the grid” amid abrupt outages from data centers.   

5. The U.S. Department of Energy’s (DOE) moves to keep old coal and gas plants from closing are a nonfactor—literally

   NERC’s assessment did not even consider the DOE’s orders, which were supposedly done to ensure the reliability of the grid. So these coal plants are not a significant factor in the improved outlook for the grid. In fact, even without those plants, the grids covering Colorado, Indiana, Michigan, and Pennsylvania are not at elevated risk this summer. The Northwest is at an elevated risk, but that has nothing to do with the one coal plant being forced to stay online. (It does have to do with drought and low snowpack, NERC said.)  

It’s long been clear that clean energy is good for the economy, good for workers, and good for utility customers. Now the analysis is clear that it’s also good for the reliability of the grid. We need to build, and NRDC is committed to an agenda to help ensure that we get the clean energy we need to power our nation forward.