Southern California Water District Plans Four Microgrids at Key Facilities

The Metropolitan Water District of Southern California is moving ahead with plans to build microgrids at three water treatment plants and a pumping station.

The water district’s board on October 13 approved the projects, a move needed to nail down $10.3 million in incentives from the California Public Utilities Commission’s (PUC) Self-Generation Incentive Program .

In response to recent wildfires and public safety power shutoffs (PSPS), the PUC modified the roughly $166 million annual SGIP program to offer enhanced incentives for microgrid-capable energy storage systems at critical facilities that benefit high fire threat districts and low-income and disadvantaged communities.

The incentives will offset nearly all the project’s $11 million to $12 million estimated cost, according to a memo from water district staff to the board.

“The current environment of declining battery energy storage costs and the potential to receive enhanced financial incentives provides Metropolitan a unique opportunity to invest in battery energy storage systems,” staff said in the memo.

Adding energy storage to the facilities, which already have on-site solar, will bolster their long-term power use, provide a hedge against expected electricity rate hikes and improve the resiliency of the electric supply at these facilities, staff said.

The water district plans to use the batteries and solar facilities as core microgrid components so the water treatment plants and pumping station can keep operating during a PSPS event or other grid outage, according to the memo. 

Staff expects to use the energy storage to reduce energy costs and greenhouse gas emissions by managing peak demand and time-of-use rates, according to a staff presentation. Energy would be stored during off-peak periods and then used during peak times.

“As we saw with the rolling blackouts over the summer, it’s more important than ever that we prioritize projects that protect critical facilities that help us deliver clean, reliable water to our vast service area,” said Metropolitan General Manager Jeffrey Kightlinger.

The projects include three 1 MW/4MWh battery systems and a 0.5 MW/2 MWh system.

The PUC has conditionally accepted three of the projects for incentives and one is on a waiting list.

The projects must be operating by mid-2022 to be eligible for the incentives. Half the incentives will be paid when the projects come on line and the reset will be paid in installment over five years.

The board approved paying engineering company Stantec $900,000 to design the battery storage systems. The water district will issue a request for proposals for building the battery storage facilities.

The water district has spent $28 million adding about 5.5 MW of solar power to the treatment plants and a visitors center.

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