Environment & Science

How LADWP Uses Two Lakes To Store Energy Like A Giant Battery

A set of pipes called the pen stock is the last stage of the seven-and-a-half mile journey for water being pumped from Pyramid Lake to Castaic Hydroelectric Power Plant in Castaic, California. Transformers and other equipment based on site transfer electricity produced at the site to a set of transmission lines that bring power to Los Angeles for periods of peak demand.
A set of pipes called the pen stock is the last stage of the seven-and-a-half mile journey for water being pumped from Pyramid Lake to Castaic Hydroelectric Power Plant in Castaic, California. Transformers and other equipment based on site transfer electricity produced at the site to a set of transmission lines that bring power to Los Angeles for periods of peak demand.
Andrew Cullen

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If L.A. is going to stop burning fossil fuels by 2045 — a key goal of Mayor Eric Garcetti's proposed Green New Deal — it must store a lot more of the excess solar and wind energy it produces during the day so it doesn't have to rely on gas and coal energy to power the city when the sun sets and the wind dies.

There's a growing focus on building big batteries — for example, the kind that use lithium ions. But L.A. needs energy storage that is far bigger than any traditional battery.

And it's found one.

The Los Angeles Department of Water and Power has turned two big lakes into a monster battery capable of storing enough energy to power tens of thousands of homes.