How electricity flows

The California ISO network is a long-distance, high-voltage transmission system that delivers wholesale electricity to local utilities for distribution to nearly 32 million customers. The ISO grid is one of the largest in the world, encompassing three quarters of California and a small portion of Nevada, delivering over 260 million megawatt-hours of electricity each year.

The ISO forecasts demand

Companies buy and sell power before it is scheduled for delivery by ISO

Day-ahead market run to clear bids, procure reserves and manage congestion

Power generated

ISO market fine-tunes supply/demand in real time

ISO operators manage flow of electricity to utility substation

ISO control ends and local energy providers take over

Low-voltage utility distribution lines carry power to consumers

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