Early heat shows we need to be prepared for anything; big thanks to consumers and other ISO partners for keeping the grid stable

By Elliot Mainzer, President and CEO |

At the ISO, we take these lessons very seriously, realizing that undue stress on the electric grid from extreme heat and increased demand no longer occur primarily just in August and September. We can probably expect a long summer of similar challenges, since forecasters are predicting higher-than-normal temperatures at least through September.

We know from the prolonged Western U.S. drought that resource conditions are deteriorating. At Lake Oroville, for example, the state’s second largest reservoir, water levels are about a third of capacity. The California Department of Water Resources has said the water could be so low in a few months that the Butte County reservoir’s hydroelectric generating plant may be forced to shut down for the first time. Hydro operators are doing all they can to preserve water and stretch supplies as far as possible. But another extremely dry year is hindering water supplies and electricity generation across the West.

California has done a lot in recent months to fortify the electric grid, including the addition of new generating capacity. Much of the new resources are in the form of battery storage units that will allow us to save solar energy when it is most abundant during the afternoon for use later in the evening when temperatures and demand remain high but solar is diminished. We are still in the process of building out that battery fleet across the summer, working with industry and our state agency partners to get as much of the planned storage on the grid as soon as we can.

Californians saw how challenging conditions can be last week, when the ISO called its first Flex Alerts of the season. We asked consumers to voluntarily conserve electricity during the evening and they stepped up in a big way. California consumers helped our control center operators balance supply and demand with no major disruptions.

The public’s cooperation was greatly appreciated and its help will be crucial again if extreme heat causes another imbalance in electricity supply and demand. We will continue to provide advance notification with Heat Bulletins and other communications so everyone has as much timely information as needed.

To stay current with forecasted supply and demand conditions, and monitor grid alerts, warnings, and emergencies, you can visit the ISO’s Today’s Outlook or download the free ISO Today mobile app. You can also stay up to date on the grid by following us on Twitter @California_ISO.

We will also continue to rely on energy imports and exports with our partners in adjacent states. We thank them for their help and coordination, as well as our partners within California, such as the Los Angeles Department of Water and Power, which provided assistance last week. While we depend on other states, the ability to import and utilize resources across such a wide geographical region is a tremendous asset. We are continuing to strengthen important partnerships with utilities across the West, as was highlighted by recent news about Montana’s NorthWestern Energy joining the ISO’s Western Energy Imbalance Market.

In a world experiencing more dramatic impacts of climate change all the time, managing California’s transition to a reliable, decarbonized grid requires many partnerships within our state and throughout the West. Thanks to all our partners for leaning in with us to keep the lights on in all of our communities.

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