Redecorating your fossil power plant with batteries

Moss Landing is the largest battery in the world. With its 400MW/1600MWh, it can provide 4h of electricity to more than 300,000 homes in California. It is expected to grow to 1500MW/6000MWh in the coming years. But its size is not the only striking thing about this project: it is also located in the buildings of a former CCGT plant.


And Moss Landing is not the only project with this particularity. There are many other projects planned or already under construction in the USA, Australia or the UK that use the facilities of closed gas or coal-fired power plants to install the necessary battery racks and inverters.


Why are old coal or gas plants being used?


One might think that it is a matter of image or greenwashing to reinforce the idea of energy transition, but this is far from reality. There are many reasons why these closed plants are a perfect place for large batteries:


1) Grid connection

This is the main factor. The Moss Landing plant for example has 2 transmission lines of 500kV and 115kV with high capacity in both and by shutting down part of the gas plant, a lot of connection capacity was available. This makes projects much cheaper by avoiding the expense of transmission lines, but above all it reduces development times by not having to wait for capacity to be allocated (and we know that this is a bottleneck in many countries).


2) Space

A project of this size requires a multitude of batteries and they need to be protected either in an enclosed building or in containers. In the case of Moss Landing, the space of the old gas turbine halls has been used to install the battery cabinets.

Moss Landing BESS


In this way, the owner of the facility saves on land rental, building costs and the cost of site clearance for the entire area. In other cases, such as the announced Stanwell project in Australia, it will be located on land adjacent to the existing coal-fired power plant.

In Vistra’s Moss Landing project alone, LG Energy, which is the supplier of the batteries, estimates that 6,000 battery cabinets have been used, plus inverters and medium voltage equipment.


3) Permitting and development

A gas or coal-fired power plant has had to obtain a multitude of permits and is supposed to be a facility ready to host a power project. This should simplify the permitting process, as well as the investment to adapt the facility to issues such as seismicity, noise, vibration, fire, etc.


Some projects around the world


  1. Moss landing (USA)

Moss Landing Power plant



Once one of the largest CCGT plants in California with 2,600MW installed, it is now best known for housing the largest battery in the world. Following the retirement of 2 of its gas turbines, it now has an operational capacity of 1000 MW.


In terms of storage projects, it currently hosts two:

Vistra Energy: it is the largest with 400MW/1600MWh capacity developed in 2 phases and with LG Energy technology. It has recently returned to 100% operation after several overheating problems due to the malfunctioning of the anti-fire systems. Vistra plans to increase the size of the project to 1500MW/6000MWh capacity.

Incidentally, Spanish inverter manufacturer Power Electronics has been involved in this mega-project, supplying 98 of its PCS equipment.


PG&E: it is a 182MW/730MWh BESS with Tesla Megapack technology. In this video you can see that the Tesla project is not in the power plant building but outside next to the transformation centre.


  1. HazelWood (Australia)

Hazelwood BESS simulation



Last year, the old Hazelwood coal-fired power station in Australia was demolished. Like all demolition videos, they are strangely hypnotic.



And the entire infrastructure of the old power station is going to be used for the new 150MW/150MWh battery being built by Engie using Fluence technology. We are likely to see more projects on this site as the grid capacity is 1600MW, currently unused making it a perfect site for future batteries.


  1. Uskmouth (UK)

Uksmouth power station


What may be one of the largest battery storage projects in Europe is planned at the former coal-fired power station in Uksmouth. The project will have 230MW/460MWh and is expected to be operational in 2024. Interestingly, this coal-fired power station has been mothballed since 2017 when it was planned to run exclusively on biomass, although it seems the project did not come to fruition.



  1. Morro Bay (USA)

Morro Bay Power Plant


The Morro Bay power plant was closed in 2014. In fact, it seems that its 3 large towers will soon be demolished, but in the meantime, Vistra energy wants to emulate what was done at Moss landing and has proposed an installation with batteries of as much as 600MW/2400MWh. As can be seen in the simulation, the batteries would be located in 3 buildings attached to the power plant and would take advantage of part of its infrastructure. Each building would contain 2,400 battery cabinets and would be surrounded by 60 PCS containers or inverters.


Morro Bay BESS project


If it goes ahead, this project will be one of the largest in the world.


  1. Wallerabang (Australia)


Wallerawang Power Plant


Another coal-fired power station that was demolished in 2021 could be the site of a major battery project.



Specifically, it would be a 500MW/1000MWh battery to be installed on the site of the demolished power plant.


  1. Poolberg (Ireland)

Poolberg power station


We end this tour of the world in Ireland, where the former Poolberg coal-fired power station will house one of the largest batteries in Europe with 75MW/150MWh developed by ESB and using Fluence technology.


Here we will not be able to enjoy the demolition of the gigantic 207m high chimneys of the former power plant as they are protected as a monument to be preserved.


Decommissioning fossil power plants are a very interesting asset for utilities as they have the infrastructure in place for clean energy projects, especially batteries, so we are sure to see more of these projects in the future (and hopefully more spectacular demolitions of fossil power plants).