Tesla + Others Team With PG&E On World’s Largest Energy Storage System

JUL 8 2018 BY MARK KANE 26

Pacific Gas and Electric Company (PG&E) requested approval of four energy storage projects totaling approximately 567 MW and 2,270 MWh (2.27 GWh), in a filing at the California Public Utilities Commission (CPUC).

The total scale of the projects is bigger than anything else we have so far seen – two of those projects will be bigger than the biggest installations in the world currently.

Tesla was mentioned as a supplier of one of four ESS – 182.5 MW and 730 MWh unit, which in terms of energy would be over 5.6-times bigger than world’s largest in Australia – 100 MW / 129 MWh. The ESS from Tesla will be owned and operated by PG&E at Moss Landing substation (three other projects to be third-party owned).

As you can see in the table below, the Vistra Energy will deliver even bigger ESS (a stand-alone, transmission-connected located in Moss Landing) – 300 MW and 1,200 MWh (1.2 GWh), which is beyond any battery storage system.

PG&E Proposes Four New Cost-effective Energy Storage Projects to CPUC

Beside small 10 MW and 40 MWh unit by Micronoc (aggregation of behind-the-meter batteries located at customer sites and interconnected to local substations within the South Bay – Moss Landing local sub-area) we also noticed significant 75 MW and 300 MWh ESS (a stand-alone, transmission-connected 75MW BESS located near the city of Morgan Hill) by Hummingbird Energy Storage.

It’s an open question who will supply batteries for the three projects aside Tesla (which with Panasonic has own battery plant).

The first project to be ready on-line by the end of 2019, while all four should be ready by the end of 2020.

Here is a description of what is planned:

“In January, the CPUC authorized PG&E to launch an accelerated solicitation for energy storage projects capable of meeting reliability needs for three specified local sub-areas in the northern central valley (Pease local sub-area and Bogue local sub-area) and spanning Silicon Valley to the central coast (South Bay – Moss Landing local sub-area).

PG&E issued its request for offers on February 28 and received offers from numerous participants. After careful evaluation, PG&E selected one offer for a utility-owned project and three offers for third-party owned projects, all to be located within the South Bay – Moss Landing local sub-area.

The proposed utility-owned project is a 182.5 MW lithium-ion battery energy storage system (BESS) located within PG&E’s Moss Landing substation. This transmission-connected BESS will address local capacity requirements and will participate in the California Independent System Operator (CAISO) markets, providing energy and ancillary services.

“Energy storage plays an increasingly important role in California’s clean energy future, and while it has been a part of PG&E’s power mix for decades – starting with the Helms Pumped Storage Plant in the 1980’s – recent decreases in battery prices are enabling energy storage to become a competitive alternative to traditional solutions. As a result, we believe that battery energy storage will be even more significant in enhancing overall grid reliability, integrating renewables, and helping customers save energy and money,” said Roy Kuga, vice president, Grid Integration and Innovation, PG&E.

The three contracts awarded for third-party owned projects also are lithium-ion battery projects.

The projects include: a 10MW aggregation of behind-the-meter batteries located at customer sites and interconnected to local substations within the South Bay – Moss Landing local sub-area; a stand-alone, transmission-connected 75MW BESS located near the city of Morgan Hill; and a stand-alone, transmission-connected 300MW BESS located in Moss Landing.

PG&E is implementing transmission solutions, rather than energy storage contracts, for the Pease and Bogue local sub-areas that would effectively address capacity shortfalls and alleviate voltage issues in those areas, respectively.

If approved by the CPUC, the first of PG&E’s proposed projects is scheduled to come on-line by the end of 2019, with the other projects scheduled to come on-line by the end of 2020. For details on the four proposed projects, please refer to the table below.”

Categories: ESS, Tesla

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26 Comments on "Tesla + Others Team With PG&E On World’s Largest Energy Storage System"

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Seven Electrics

The title is inaccurate. It might be the world’s largest battery storage system, but other energy storage systems are bigger. The worlds largest pumped hydro is 3000 mWh.

Scott Franco

Correct, PSH outclasses any other storage technology in terms of both cost per kWh and total capacity. California has and is building more PSH all the time.

Scott Franco

This government article gives a good overview of the PSH situation in California:


Which states:

“Commercially deployed since the 1890s, pumped hydroelectric energy is the dominant utility-scale electricity storage technology in California and worldwide”.

PSH dovetails with California’s [1] Need to manage water in general. California is underserved for water storage in general. The majority of water in California still flows to the ocean [2]. We (the people of California) voted to increase water storage here several times, but that money was effectively lost to political infighting (as extensively detailed elsewhere). PSH projects give locations to store water that are unrelated to natural water sources, because the water is pumped uphill to PSH reservoirs and then let back down hill again, meaning that new reservoirs can be created anywhere there is access to the aqueduct (which itself flows the length of California).

[1] Calling it “Cali” is both tempting and in vogue, but I won’t. My wife’s native Colombia has a city named Cali.

[2] Realizing full well that a goal of retaining %100 of the water for human use is an insane goal. It would make California a desert interrupted only by lawns and potted plants.

Mister G

As I type this thousands of California residents will be without power due to heat wave overwhelming grid. CONNECT THE DOTS ON CLEAN AIR WAKE UP EARTHLINGS co2.earth


No need to make stuff up.
We had it the worst here in SoCal. At my work it was 116F Friday. Unless near a fire, there were no blackouts. None! This is not Enron time anymore. The Cali grid is fairly robust. Even during the worst of it they never issued any warnings about the grid here other than “Restricted Maintenance Operations” which warns the operators not to cut power for maintenance purposes and was only for Friday. The rest of the days the grid was normal.
Main page:

Mister G



I’m not sure if LADWP problems show on the ISO website. I was monitoring live during the past few days and saw no major issues. They predicted the load peaks very accurately every day. I didn’t even get a flex alert this time.

Seven Electrics

Some estimates have hydrogen energy storage in salt caverns at only $0.02 per kWh, which is 5000x (yes, five thousand times) cheaper (https://www.nrel.gov/docs/fy10osti/46719.pdf) than $100 per kWh for lithium. With that savings, you can buy a lot of solar and wind.


I guess you didn’t read this in the linked report:

“Cost results for the analysis are presented in terms of the annualized (“levelized”) cost for producing the energy output from the storage system: electricity fed back onto the grid during peak hours ($/kWh)”

Your $0.02 for the hydrogen system is the cost per kWh of electricity delivered by the system.

Your $100 for the battery system is the cost per kWh of capacity.


No, he read it. He has hoping you won’t. He is doing this crap all the time and on purpose. He is part of the H propagandists while pretending to be interested in evs.

Mister G



5000x cheaper? LOL. Most ignorant comment of the month.

Some Guy

Sure, a great idea. Use a whole lot of electricity to make hydrogen and then a lot more to compress it an shove it down a salt cavern. Its not like that hydrogen has a tendency to try to escape even through steel walls. Salt caverns never leak either, that’s why natural gas can be stored there without risk. If you remember, the leak in a natural gas storage facility was the reason for the first 80 MWh battery to be built in California a while back, as the leaky cavern had to be closed down.

BTW: At 100$/kWh battery cost, the energy storage cost is only 0.01$ per kWh transferred for a system that kan survive 10000 full cycles. Granted, a wee bit of maintenace comes on top, but then again, a battery that has soldiered on bravely for 10000 cycles will not die instantly at the cycle #10001.
And if there is a vast surplus of energy, the market might even pay you to take it, then storage is essentially free…

Ocean Railroader

This is a very cool project this is only the tip of the iceburg.

Think of what would happen to natural gas demand if this project was scaled by by ten times.

Such as if the Tesla unit was grown by a factor of ten from 182 megawatts a four for four hours to 1,820 megawatts for four hours.

If the Tesla project was scaled by by a factor of 25 times then it could produce 4,550 megawatts for four hours which would equal the output of five of California’s natural gas plants for four hours.

If this project was scaled by a factor of 50 times it would would equal 9,100 megawatts and it would be end of 8 natural gas power plants in California.


What is even better: because it is a battery it can work both ways (charging or discharging) and its regulating capacity is 2x its nominal power. So in your examples: 9100 resp. 18200 MW

Scott Franco
So my only issue with this is the location. The Moss landing power plant was an oil burning plant, but got converted to natural gas. Putting a battery behind a NG powered plant is a headscratcher. NG plants are among the most demand matchable power generators available, IE., they can be throttled up and down to match demand. So why would you need store power from that plant? Using it is charge batteries then send it on later would actually make the power cost more/be less efficient, because of power lost in charging and discharging the batteries. Here’s what I think is really going on, unstated by the article. There are NG peakers spread all over the valley (silicon valley). These are small NG plants used to provide extra power to compensate for power peaks in hot summer days. These plants were built since the “Gray out”, the Gray Davis caused power grid shortages that happened about the turn the century. These are cheap but small power plants. Silicon Valley companies have money and (increasingly) political power. You don’t tell the valley they need to shutdown operations in the middle of summer, its one reason governor Davis lost his job.… Read more »
Some Guy

In order for a peaker plant to work, it often runs at low turbine speed all the time, and quickly ramps up within minutes to full power.
Given a sufficient battery size, the plant maybe able to get some additional time required for a cold-start, perhaps even cranking the gas turbine to speed by electrical power, before the burners kick in. Thus the demand for 20+ hours of idling (that costs money) might go away.
Ramping down also takes a few minutes, when the plant still produces excess energy that maybe no longer needed, and it could be harvested to charge the battery.

Also, a battery comes in handy in case of a black out. When the grid goes down, only a handful of power plants are capable of a black-start, meaning that they can start-up without relying on power drawn from the grid for e.g. control systems and fuel manifolds etc..

Scott Franco

Moss landing is not a peaker plant. It is a full on power plant that supplies the entire Salinas valley. Please reread what I said.


The actual location is not as important as you try to make it. The battery pack can balance for failures anywhere in the grid, not just this one NG plant.

The NG plant and the batteries can both dump power into the grid at the same time to make up for whatever plant goes off line, or if demand simply exceeds all of the plans even if all are online.

Scott Franco

Assuming zero transmission loss, that is true. Transmission loss is not zero.


Transmission loss of minimal. More important is transmission capacity. Perhaps this location has a lot of spare capacity in directions (north, south, etc.) that matter.


Transmission loss would be measured from producer to consumer, not producer to producer.

If this location is equidistant from the consumer as it is to whatever power production facility went down, the transmission loss would be identical to if this NG plant went down. Even if this plant was 100 miles north of the consumer, and the plant that failed was 100 miles south (as wire travels).


Editors! Please, please stop saying the Australia battery is the world’s largest. It is not and never was. Kyushu Electric installed a 300 MWh battery in 2016.


The Kyushu Electric is 300 MWh, but it is only 50 MW output. On the other hand, the Tesla Australia project was less MWh at 129 MWh, but HIGHER MW output at 100 MW.

If you want to get pedantic, then yes, it has higher MWh rating. But the whole point of the common press is to boil down information into terms that non-technical people can understand. And “world’s largest” is much easier to understand than “highest MW rated output” and then explaining the difference between MW and MWh to the general public, and what the added value is in the Australia installation is of having higher MW compared to more MWh when it comes to rapid response for protecting against blackouts. None of which is trivial to explain.


At some in the decision between clarity and readability vs. being 100% pedantic has to be made.


“Most powerful” is easy for the layman to understand.

This article says: “…730 MWh unit, which in terms of energy would be over 5.6-times bigger than world’s largest in Australia”.

They’re clearly talking about capacity, not power. It’s flat wrong to talk in terms of capacity and then say Australia is the world’s largest. I know the editors here value accuracy, even if certain readers don’t.


Out here in the west, Advanced Rail Energy Storage makes more sense than a bunch of batteries. We have no shortage of steep hills, it’s a dirt simple idea, almost zero environmental impact, no rare elements, or minerals need to be mined, scalable and likely have better efficiency, with less loss than batteries. For those that haven’t heard about it, here’s a link to the company trying to get started-