California Drought: Summer Power Supply 'Looking Good'

The California Independent System Operator, or CAL-ISO, which manages the state's energy grid, releases its summer assessment Thursday. 

The preliminary summer power supply outlook shows there is enough energy to meet demand.

"Our reserves are still going to be about 10 percent," said Steven Greenlee, CAL-ISO Senior Public Information Officer. "So, we expect to be able to make all of the forecast, plus a 10 percent cushion. The minimum cushion that we want to see is 7 percent. So, for this summer, we're actually looking pretty good."

The National Oceanic and Atmospheric Administration forecast is for a warmer than normal summer in California and for Nevada, Oregon and Washington.

Greenlee said the biggest concern for CAL-ISO this summer is wildfires.

"There is nothing that can take out a transmission line quicker than a wildfire," said Greenlee. "And it's not just the fire actually touching the line, it can be hot smoke."  

Steven Greenlee with the California Independent System Operator, said managing the state's power grid includes "running different scenarios" to forecast power demand.   Andrew Nixon / Capital Public Radio 

He said electricity from solar resources, and hydroelectricity from the Pacific Northwest, can make up for a decline in California hydropower due to the drought and this winter's record-low snowpack in the Sierra Nevada.

Greenlee said in-state renewable energy sources, such as solar, wind and geothermal, make up 24 percent, or 16,000 megawatts, of the electricity supply in California.  He said the "total portfolio mix" is 66,000 megawatts. Greenlee explained that 1 megawatt will power about 750-1,000 average homes.

"Grid reliability is our number one core job," said Greenlee. "To make sure the grid is always functional comes with lots of challenges, from transmission line outages to balancing supply and demand."

Greenlee said CAL-ISO will provide more details about the summer supply forecast and updated information about the renewable mix when it releases the assessment this week.