- The increasingly renewables-reliant grid passed a major stress test last month when the heat wave that settled over parts of the country sent grid operators scrambling for electricity supplies and customer conservation. On the whole, there were few major interruptions.
- The California ISO issued multiple calls for conservation last week, receiving strong responses that helped to keep the grid stable. But that followed an outage earlier in July that cut power to over 80,000 customers around Los Angeles.
- In the Northwest, temperatures have recently hovered in the 90s, but the system performed well despite some resources offline. Talen Energy's Colstrip coal generating facility in Montana shut down a month ago but it generated relatively little news because it resulted in no disruptions.
A sweltering summer across parts of the country has at times caused grid operators to call for energy conservation, but generally speaking, the nation's electric system has responded effectively. Some observers say it is proof the integration of more intermittent renewable power can be effectively managed, while others caution it is too soon for sweeping statements.
On the one hand, about 80,000 customers around Los Angeles lost power last month during a heat wave. The Environmental Defense Fund (EDF) noted that it wasn't due to a lack of supply but an overloaded electric grid.
Tim O'Connor, director of EDF’s California oil and gas program, wrote in a blog post that "grid infrastructure investments and business models simply aren’t keeping up with technology advancements and changing consumer needs of today’s America."
On the other hand, the Northwest electric grid lost a major generator when Talen Energy's Colstrip coal-fired plant in Montana quietly went offline. A mix of maintenance and compliance issues forced all four of its units offline, amid a national debate over the necessity of fuel-based power plants, whether renewables can maintain grid reliability, and if the government should intervene to save aging plants.
Texas, with its high wind-power penetration and electricity-only markets, has also fared well with the recent heat. The state has an electricity reserve margin above 10%, which analysts say has helped the Lone Star State maintain reliability despite retirements.
Michael Webber, deputy director of the Energy Institute at the University of Texas at Austin, told Digital Journal that if the state can make it through the summer without disruptions then wind energy advocates will have a reliability argument.
Last week, California's grid operator called for conservation and the response from residents was more than anticipated. Typically, according to Greentech Media, a two-day call for conservation will result in less load displacement on the second day as customers nudge air conditioners back up.
GTM noted that Californians reduced demand 450 MW on July 24 and then, surprisingly, by 540 MW on July 25.