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​Summer Readiness and Flex Alerts

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

The California ISO predicts adequate power this summer largely because of above-normal hydroelectric supplies. While the likelihood of system-wide power outages is low, the ISO asks consumers to help during times of grid stress by answering the Flex Alert call to conserve. When consumers reduce energy use at critical times, operators can better balance the grid and prevent dire emergencies, including widespread power outages.

2019 Summer Outlook

  • Hydroelectric conditions are well above average
  • Lower potential for calls for Flex Alerts
  • Forecasted peak demand of 46,511 MW is relatively unchanged from 2018
  • 2,702 MW of generation will retire or mothball
  • Risk of reserve shortfalls increase later in summer as snow runoff declines

Annual hydroelectric production

In its annual 2019 assessment, the ISO predicts adequate power supplies to meet the summer need; there is a slight chance it could face operational challenges later in the season as hydropower wanes and evening demand spikes as solar generation output decreases.

See the Summer Loads & Resources Assessment report for more details.

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

Public Safety Power Shutoff (PSPS)

Learn more about the utilities’ Public Safety Power Shutoff (PSPS) programs, as part of wildfire risk mitigation plans.
View a fact sheet on how the ISO manages the grid during a PSPS.


​Energy Matters newsletter

Learn about the ISO’s summer projections for demand, what consumers can do to help during Flex Alerts, and how to stay informed on summer outlook and grid conditions.

Subscribe to Energy Matters newsletter