Large-Scale Battery Project Ready To Go Online In Imperial Valley
When engineer Bruce Townsend walks around this hot and dusty construction site in El Centro, it is not the massive gas-fired power plant nearby that catches his imagination. His eyes are planted firmly on the future of energy — and the low-slung metal building that will house it.
"This is really going to take off," Townsend said.
Townsend was referring to a nearly $38 million battery, the largest battery of its kind in the western U.S. He was the venture's original project manager.
KPBS visited the project site earlier this summer, before the individual lithium ion batteries were installed.
Looking at the mostly empty room, Townsend said the building will be filled with batteries wired together.
"They look almost like a small box, approximately three inches wide, seven inches long and about six inches tall," Townsend said. "And there are lots of them stacked together. Wired together in a tray."
Once the batteries go online, they will serve as an energy reservoir that can hold 30 megawatts of power. That's enough to light up roughly 24,000 homes.
Operators can release up to 20 megawatts of that capacity in an hour, Townsend said, and that's a pretty big stream of electricity.
He said that surge can be available at a moment’s notice.
"Everything takes time to cycle and especially steam turbines," Townsend said. "You have to boil water. While your combustion turbines, otherwise know as gas turbines, do speed up, it takes anywhere between five to 20 minutes, even 30 minutes depending upon the model, to come up to full speed."
Since batteries can turn on instantly, the facility can keep energy flowing if the rest of the grid fails and there's a blackout. The lithium ion reservoir can also be used to restart the nearby gas-fired power plant. Even gas-fired power plants need electricity to run.
Townsend said computer algorithms can make split-second decisions that can manage the flow of power.
A nearby switching station can push the battery power out onto the grid, or pull power off the grid and direct it into the storage facility.
When there's too much solar being produced in the middle of the day, Townsend said, grid operators offer to pay the district to take the excess power. It is currently the only kind of power facility that can make money taking in electricity and sending it out, Townsend said.
"We can charge the batteries, provide system reliability, and do it on somebody else's dime. It doesn't get any better than that," Townsend said.
Batteries will also allow grid managers to smooth out the renewable energy flowing through power lines. That's important because the desert valley boasts geothermal plants, wind farms and solar farms and all those renewable energy streams present management challenges that don't exist with a gas-fired or nuclear plant.
"Renewables by their nature fluctuate throughout the day. Solar doesn't produce at night. If a cloud comes up the solar production goes down. So it constantly goes up and down. Up and down. And our customers need a steady power source," said Robert Schettler, a spokesman for the Imperial Irrigation District.
The battery evens out the power flow by putting power into the grid to fill in production valleys. The same facility can eliminate power spikes by pulling power off the grid and storing that energy.
The battery can also prop up the grid if there's an unexpected problem.
In fact, western power managers required the district to build a battery to atone for failures during a cascading power failure in September 2011. That outage crashed the grid in three states and Mexico. Schettler says utility officials reviewed their options and decided to go much larger.
"The energy industry is ever-changing and fast-paced and regulations are changing daily almost, it seems like. So this is a way we're trying to get ahead of an issue," Schettler said.
But the technology is still new and remains largely unproven. Proponents see the technology as a critical step to improve the outdated and fragile U.S. power grid, but there are hurdles to overcome.
"They are still quite costly, but I think more than that is the fact that it is still a new market. This market, in many degrees, is not more than a decade old," said Ross Bruton, a London-based energy analyst for the investment firm Frost and Sullivan.
He said California is a step ahead because regulators ordered the state's three major investor-owned utilities to increase energy storage capacity.
Engineer Townsend said large utility-scale batteries, like the one in the Imperial Valley, appear to be the most practical option to hit state goals.
"And we have a lot of other organizations, a lot of other utilities, really around the world, following us to see what we're doing so they can increase the reliability of their systems also," Townsend said.
The Imperial Irrigation District battery project is expected to be online as early as next month.