World’s largest Tesla megapack battery project approved for California

Plans to repurpose California’s ageing Moss Landing gas power plant as the biggest Tesla “big battery” power plant in the world are quickly taking shape, after a 182.5MW/1.2GWh project was given the all-clear to go ahead in Monterey.

Local media reported on Thursday (Australian time) that the Monterey County Planning Commission had unanimously approved a joint project between Tesla and California utility PG&E to build a facility 10 times the capacity of South Australia’s ground-breaking Hornsdale Power Reserve to store and dispatch wind and solar energy.

The project will use Tesla’s relatively new utility-scale battery product, the Megapack, which was launched in July of 2019 with collaborations like this – and the nearby Vistra Energy 300-MW/1,200MWh Vistra Moss Landing Energy Storage system – in mind.

As Tesla said at the time of the Megapack launch, the batteries have been designed to act as “a sustainable alternative to natural gas ‘peaker’ power plants … (which) cost millions of dollars per day to operate and are some of the least efficient and dirtiest plants on the grid.”

All up, PG&E has been seeking approval for four energy storage projects at the Moss Landing plant, which first started sending power to the grid back in the 1950s, but was updated with two combined cycle units in the early 2000s, making it the largest generator in California at 2560MW.

Over the next two decades, the increasingly expensive to run plant changed hands and by mid-2018, its current owners – subsidiaries of PG&E – had decided to make the shift to grid-scale battery storage.

“It’s huge for the area and as you know the power plant has been gradually shutting down and they producing about one-tenth of the power they used to produce in the past and that hurts us from a tax standpoint,” said Monterey County Supervisor John Phillips.

“It just makes sense you have the transmission lines coming in, you’re producing the power during the day… but then you’re losing it before you need it so it just makes sense that you store it and then it just goes out,” Phillips said.

With all approvals in place, Tesla and PG&E hope to break ground on the project next month and have it completed by the end of the year. Certainly, Tesla’s efforts delivering the “big battery” for South Australia show how fast the company can move on such projects.

As Giles Parkinson reminds us here, the 100MW/129MWh Tesla big battery at Hornsdale, in South Australia, was installed with much fanfare in less than 100 days in late 2017 after a Twitter exchange between Tesla CEO Elon Musk and Australia software billionaire Mike Cannon-Brookes.

Since then the world-first facility has gone from strength to strength, delivering various benefits to the majority renewables grid in South Australia and revenue to its owner, Neoen Australia.

Neoen this week reported revenues at the Hornsdale Power Reserve had jumped by 56 per cent in the last quarter of 2019, primarily due to a jump in the value of frequency and ancillary services, while revenues across the full year had climed 14 per cent, thanks mostly to earnings from battery storage.

PG&E, which continues to struggle through a bankruptcy fuelled by California’s disastrous wildfires, no doubt hopes that it can have similar success with the big batteries it is planning for Moss Landing.

As IEEFA noted in an analysis last year, while projects could see delays, or even cancellations, due to PG&E’s ongoing Chapter 11 and restructuring process, these investments in grid-scale energy storage look like a step in the right direction.

IEEFA quotes the U.S. Department of Energy’s National Renewable Energy Laboratory, or NREL, report from 2019 that found batteries could ultimately satisfy “a substantial portion” of U.S. peak capacity needs.

“Assuming current conditions and demand patterns on the U.S. grid, the analysis identified a practical energy storage peak power potential of about 70,000 MW,” IEEFA said.

“That includes approximately 28,000 MW from four-hour battery storage arrays, 8,000 MW from six-hour storage systems and 34,000 MW from eight-hour storage projects.”