Flex Alert in Effect Today From 5 p.m. to 10 p.m.

FOLSOM, Calif. – The California Independent System Operator’s (ISO) first Flex Alert of
the year takes effect this afternoon, with consumers encouraged to voluntarily conserve
electricity from 5 p.m. to 10 p.m. to help maintain grid stability while California and much
of the Southwest experience triple-digit temperatures the next several days.

Once the Flex Alert conservation period begins, consumers are asked to:
• Set thermostats to 78 degrees or higher, if health permits
• Avoid using major appliances
• Turn off all unnecessary lights

Consumers are also encouraged to use fans for cooling and unplug unused electrical
items. Additional tips can be found at the website, Flex Alert.org, where people can also
sign up to receive Flex Alert notifications.

To be as comfortable as possible during the Flex Alert hours, consumers are also
encouraged to manage electricity use by taking these steps before 5 p.m. today:
• Pre-cool your home by lowering the thermostat
• Use major appliances, like your dishwasher, and clothes washer and dryer
• Close window coverings to keep your home or apartment cool
• Charge electronic devices
• Charge electric vehicles

In a conference call with reporters yesterday, Elliot Mainzer, president and chief
executive officer of the ISO, said the Flex Alert was being called “in a preponderance of
caution” because demand and supply forecasts for today show a relatively modest
shortfall of about 300 megawatts (MW) of electricity available to the grid. Grid operators
believe voluntary conservation should close the gap, making the likelihood of rotating
outages remote.

“We certainly know from experience, including last August and September, that
Californians can make a huge difference in helping maintain overall grid stability by
taking these very straight-forward and pragmatic steps to help conserve,” Mainzer told
reporters.

Today is expected to be the hottest day of the week in Northern California, with high
temperatures forecasted to reach between 100 and 110 degrees. Heat warnings
continue to be in effect for much of Southern California, and states across much of the
Southwest are experiencing similar temperatures and stress on their electric grids.
When past Flex Alerts have been called, consumers have answered the call and cut
back their electricity use. Those actions have helped California avoid or limit power
outages that can, if conditions persist or worsen, become necessary when demand for
electricity outstrips capacity.

While typically set from 4 p.m. to 9 p.m., the precise time for the Flex Alerts varies
depending on hourly projections of supply and demand. Grid operators said the 5 p.m.
to 10 p.m. period will be the most challenging time for the electric system today based
on those projections.

The ISO continues to closely monitor weather and grid conditions and will report later
today whether a Flex Alert is also needed on Friday.

For the most up-to-date information on emergencies, follow us on Twitter at
@California_ISO.

Click here to learn more about System Alerts, Warnings, and Emergencies. You can
follow grid conditions in real time at ISO’s Today’s Outlook, or download the free ISO
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