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Battery Storage Begins to Find a Home at Some Water Utilities

Irvine Ranch Water District is installing Tesla battery systems at 11 of its facilities, saving money on its power bill and helping to balance demand on the regional energy grid. General Manager Paul Cook explains the strategy.

Written by Matt Weiser Published on Read time Approx. 5 minutes
A Tesla battery pack is lowered into place at Irvine Ranch Water District’s Deep Aquifer Water Treatment Plant. It's one of 11 facilities within the district that are getting battery systems in a move to save money and balance out demand on the regional power grid.Photo Courtesy Irvine Ranch Water District

High-capacity batteries aren’t just making electric vehicles viable. They’re also beginning to transform water utilities.

In Southern California, a number of water utilities have begun to install large batteries alongside their pumping plants and water treatment facilities. The idea is to store energy in the batteries overnight, when energy is cheaper. Then during the daytime, when power is more expensive, a water agency can tap that battery power for its routine operations.

This saves water ratepayers money, because energy is often the most expensive component of treating and moving water. It also helps the regional electric grid meet demand during peak hours, because batteries effectively eliminate some of that demand. And it’s a large share of demand: Moving, treating and heating water account for nearly 20 percent of all energy consumed in the state, according to the California Energy Commission.

In the water sector, the Irvine Ranch Water District in Orange County has emerged as a pioneer in combining battery systems with its water distribution and wastewater treatment operations. Although other Southern California water agencies are installing batteries, Irvine Ranch was one of the first and largest adopters. It signed a deal with Advanced Microgrid Solutions to install Tesla batteries at 11 of its facilities, including wellheads and sewage treatment plants. The first battery installation went online in October, with more expected in the next few months.

Water Deeply spoke with the district’s general manager, Paul Cook, to learn more about the effort.

Water Deeply: When did your water agency start getting into battery systems?

Paul Cook: We started working on this back in 2015 – what’s out there and who has the expertise and what are the missing pieces. Batteries are batteries. But the missing piece that we could tell was the software that goes along with the batteries. It’s the software that can actually learn how your system is working. Our first priority is always to make sure we can pump water, treat sewage and do all these things we have to do. And I don’t want to put another layer of responsibility on the operators I have, who already have enough on their plates.

So that whole problem was solved by a private company called Advanced Microgrid Solutions.

The third leg of that stool is the California Public Utilities Commission, which was offering grant incentives through Southern California Edison so private companies could procure equipment and then work with a host. In our case, we were the host agency. We’ve got wells, treatment plants, wastewater recycling facilities.

Water Deeply: What’s happening in the energy market that is driving projects like this?

Cook: Renewables create a ton of power on top of each other. That gets to be a bit of a challenge to balance the electric load on the grid. We also had a nuclear power plant, San Onofre, and it got shut down a couple years ago. One element of what that facility did is it regulated the grid voltage. It did a really nice job balancing voltage – making sure level of electricity was very consistent. So it was a real challenge for the electric utilities when San Onofre got shut down.

All of us water agencies use a lot of power, and I think that’s why a lot of us water agencies are getting phone calls from some of these battery companies hoping to make the renewables work better. We can charge anytime we want. We’re not limited to certain times of day.

Water Deeply: What risks did this pose to your water agency?

Cook: In just a few months, we got those 11 sites nailed down and submitted for funding through a program offered by the Public Utilities Commission. Then we negotiated terms with Advanced Microgrid Solutions. It ended up being a pretty great example of a public-private partnership. They certainly took on the financial risk because, really, it’s their batteries. Everything having to do with the system is their technology. Irvine Ranch Water District paid nothing to install the batteries.

Water Deeply: What’s the basic concept of the battery systems? How do they work?

Cook: We charge the batteries at night when more power is available and it’s cheaper, and then discharge them during during peak times. It’s that discharge during peak times that relieves the electric grid from the demand posed by our facilities. It also saves lots of money, because usually we’re paying a lot more for electricity during those times. Our electric bill gets to be a lot smaller.

It saves Irvine Ranch Water District money on our electric bill while sharing those cost savings with the contractors. They’re also getting incentives from Edison, which is now saving money because they don’t have to go out and build peaker plants to avoid brownouts or blackouts.

Water Deeply: What are the benefits for your ratepayers?

Cook: Our expectation is that our electric bill will be lowered by about a half million dollars a year.

In parallel with Advanced Microgrid Solutions, we have to create an electric bill as if we didn’t have the ability to use the batteries. Then we compare that to the batteries being used. That’s how we net out the savings, and contractually we split those savings with Advanced Microgrid Solutions. If they don’t perform, they owe us about a quarter of a million dollars.

Water Deeply: Are you planning to integrate these batteries with solar power or other renewable energy sources?

Cook: Our projects are pure battery, but in the future batteries will be married up with renewables. We have a project looking at that right now.

We have a new water treatment facility (Baker Water Treatment Plant) that we brought online just about a year ago. It’s a regional plant that serves Irvine and four other water districts. It wasn’t online yet when we planned the batteries. We’ve been running it for about a year now, so we know when the pumps come on, we know what the load profile looks like and we can provide lots of data to our partners at Advanced Microgrid Solutions. We have a couple of big, buried reservoirs at that plant that are perfect for setting up photovoltaics. We can mount panels on the roofs of those reservoirs, but the panels will be owned and operated by the private company.

It’s really having the land and having the load that make sense. You can put up photovoltaics and sell it back into the grid if your local utility wants it. I think in this case it’s going to make a lot of sense because we know we can most likely use all the power generated by the photovoltaics with our facility. It’s this whole integration, all-of-the-above approach: Conservation and efficiency married up with recycling. But new resources are necessary, too. It’s all these pieces coming together to make the grid more reliable, which is good for everybody.

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