Skip Ribbon Commands
Skip to main content
Sign In

​Summer Readiness and Flex Alerts

The ISO encourages Californians to learn about the summer energy outlook, and how to conserve electricity when a Flex Alert is issued.

While the California ISO predicts a low probability of system power outages this summer,
below-average hydroelectric supplies, widespread heat and reduced imports could combine
to create shortages later in the season.

2020 Summer Outlook

  • The ISO anticipates adequate resources to meet demand this summer.
  • Forecasted peak demand of 45,907 megawatts (MW) is relatively unchanged from 2019.
  • 1,952 MW of generation will retire and 1,990 MW of generation will be added.
  • Hydroelectric conditions are below normal.
  • Under more extreme scenarios, low hydropower supplies combined with late summer high heat and reduced imports could cause energy shortfalls.
  • Risk of energy shortages in late summer increase in the evening hours.

Annual hydroelectric production

Summer Loads and Resources Assessment

In its annual 2020 assessment, the ISO predicts adequate power and low chance of load shedding, except if late summer heat hits a larger area beyond the ISO footprint, making imports tighter.

See report for more details.


Public Safety Power Shutoff (PSPS)

To reduce wildfire risk, California’s utilities may need to proactively turn off power, or “de-energize,” electrical lines during extreme weather conditions. Under the utilities’ Public Safety Power Shutoff (PSPS) program, the state’s largest investor-owned utilities – PG&E, SCE, and SDG&E – are required to monitor their territories for weather and environmental factors that contribute to wildfires. If the risk of fire is high, the utilities may decide to turn off power on electrical lines to prevent causing a fire to ignite.

Visit the PSPS website to learn more.

Fact Sheet - ISO's role in PSPS events

Flex Alerts

A Flex Alert is a call for consumers to voluntarily conserve electricity when there is a predicted shortage of energy supply, especially if the grid operator needs to dip into reserves to cover demand. When consumers reduce electricity use at critical times, it can prevent more dire emergency measures, including possible power outages.

​Visit for conservation tips, to subscribe for Flex Alerts and more.

Alerta "Flex" - en Espanol

​See past Flex Alert notices