Inside Clean Energy: Taking Stock of the Energy Storage Boom Happening Right Now

A new forecast shows a near-tripling of global storage capacity in 2021 compared to 2020, which also was a record year.

Workers install battery modules at the Manatee Energy Storage Center in Florida, being developed by Florida Power & Light. The project, on track to be complete by the end of the year, will have 409 megawatts of capacity, which would make it the largest battery storage project in the world by capacity. Photo Courtesy of Florida Power & Light
Workers install battery modules at the Manatee Energy Storage Center in Florida, being developed by Florida Power & Light. The project, on track to be complete by the end of the year, will have 409 megawatts of capacity, which would make it the largest battery storage project in the world by capacity. Photo Courtesy of Florida Power & Light

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Global energy storage development is increasing so quickly and on such a large scale that it’s sometimes difficult to grasp the significance of what’s happening.

The energy research firm Wood Mackenzie reports in its most recent forecast that, globally, 12.4 gigawatts of energy storage capacity will come online in 2021, up from 4.9 gigawatts in 2020, which was then a record. Almost all the new storage systems are batteries.

To help put that into perspective, the world reached a landmark 1 gigawatt of new energy storage capacity in 2016. Five years later, that record year is what happens in a good month.

The growth in energy storage is just getting started. Wood Mackenzie projects that new global storage capacity will increase each year, to 70 gigawatts in 2030.


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So, we’re looking at a near-tripling of new storage capacity in 2021, and a 14-fold increase from 2020 to 2030.

The new 2021 capacity can discharge 28 gigawatt-hours of electricity before needing to recharge, up from 10 gigawatt-hours for the new capacity in 2020, the report says.

The new storage systems can, on average, run for longer than before, with a duration of 2.26 hours (gigawatt-hours divided by gigawatts) in 2021, up from 2.04 hours in 2020. The increase means that many of the new battery systems can fill longer gaps when other resources are unavailable.

There are still big unknowns about how the market will develop, the extent of government aid and the emergence of new battery technologies, making it challenging for forecasters.

“We’re in an experimental moment,” David Victor, co-director of the Deep Decarbonization Initiative at University of California, San Diego, and a senior fellow at the Brookings Institution. “We’re testing a lot of stuff, and the hypothesis that storage adds huge value to the grid is being sustained.”

He told me that much of the value of energy storage comes from the way it can work alongside wind and solar, at the grid level or in projects where renewable energy sources and battery storage are placed next to one another.

But project developers and grid operators mostly have to guess at how much storage they need to build, or how to determine the right mix of various kinds of storage, he said.

Most of the batteries being used today can run for two to four hours on a charge, but a grid that relies on much more storage is likely to need a mix of short-duration and long-duration batteries.

And batteries are not the only energy storage technology. For example, pumped hydroelectric storage is an old, and still vital, contributor to the grid. One of these days, I’ll write about pumped hydro, systems that pump water to a high reservoir at times of low electricity demand and then release it at times of high demand, allowing gravity to push the water through a turbine and produce electricity.

“People can see a future where there’s a much bigger—like 10-fold, 20-fold—increase in storage services over a decade,” he said. “That future is starting to come into focus, but it’s really still a murky vision because there’s a lot of experimentation continuing to be done.”

Still, in 2021, we can say with certainty that we’ve entered an era of super-size energy storage projects. Two examples:

Moss Landing Energy Storage Facility in California went online in December 2020, with 300 megawatts of capacity, and then added 100 megawatts in August of this year, which I’ve written about a few times. The project, which operates under a contract with the utility Pacific Gas & Electric, is the largest battery storage facility in the world. PG&E has said the batteries are a cost-effective way to make the grid more efficient, by storing renewable energy, and more reliable, by being available at times when other resources are not.

A detail shot of stacks of battery modules at the Manatee Energy Storage Center. Photo Courtesy of Florida Power & Light
A detail shot of stacks of battery modules at the Manatee Energy Storage Center. Photo Courtesy of Florida Power & Light

Manatee Energy Storage Center in Florida is on track to be completed before the end of the year. When that happens, it will be the largest battery storage facility in the world in terms of capacity, with 409 megawatts. Florida Power & Light, which will operate the project, told me it has installed about 30,000 of the facility’s 50,000 battery modules. The project was designed to store electricity from the neighboring Manatee Energy Solar Energy Center, allowing the utility to be more flexible in how it uses solar power.

Another recurring theme with energy storage is that this is an aspect of the energy economy in which the United States has a head start. The United States and China have a large majority of the existing capacity, and Wood Mackenzie is projecting that the two countries will have 73 percent of the world’s total capacity in 2030.

The Biden Administration recognizes that the country has an interest in continuing to be a leader in battery technologies, which can be an asset for grid storage and for electric vehicles. The U.S. Department of Energy announced in June a goal to reduce the costs of long-duration energy storage by 90 percent by 2030, which covers technologies that can discharge electricity for at least 10 hours on a charge.

The energy storage boom is here, and even with my decade-plus of experience covering energy, I have little certainty about where this ride is heading. 

Victor said the uncertainty about the path of energy storage’s growth is like a Rorschach test, where different people see different things, and there is no right answer.

“What you can see are the pieces of a storage industry coming together in a huge deployment into the future,” he said.

Other stories about the energy transition to take note of this week:

North Carolina Passes Energy Bill Calling for Carbon Neutrality by 2050: North Carolina Gov. Roy Cooper has signed a bill passed by the state legislature last week that has some big benefits for electric utilities and also says that state regulators must set rules to make the electricity sector carbon neutral by 2050. The bill came together in fits and starts because of the dueling priorities of Duke Energy, which wanted legislation that would allow it to increase rates more easily, and Cooper, who wanted the bill to include a pathway for cutting emissions. The result is a compromise, but the specifics about carbon reduction are being kicked to the North Carolina Utilities Commission which will propose the rules, as Adam Wagner reports for The News & Observer of Raleigh. The bill also includes an interim goal that utilities must cut emissions 70 percent from 2005 levels by 2030. Environmental groups are pleased with the legislation because they were able to get some of their priorities addressed, but consumer advocates are warning that the result may be a big increase in electricity costs for the public.

GE Offshore Wind Turbines Reaches Record 14 Megawatts: GE Renewable Energy said that its largest offshore wind turbine is now operating with a capacity of 14 megawatts, which is a record. A power plant’s capacity—a wind turbine is a power plant—is the amount of power it can produce when running at full intensity. The company announced last week that its Haliade-X turbine can operate at 14 megawatts following fine-tuning on a design that was previously going to top out at 12 megawatts, as Emma Penrod reports for Utility Dive. The Haliade-X is set to be used in the Vineyard Wind 1 project off Massachusetts, among others. The model is about 850 feet tall, which is taller than the Statue of Liberty. By increasing the turbine’s capacity, developers can generate more electricity using fewer turbines, and reduce the costs of installation and maintenance.

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GM Gets Battery Maker to Pick Up Most of Recall Costs: General Motors said it has reached an agreement with the battery manufacturer LG in which the battery company will pay $1.9 billion of the $2 billion in costs associated with a recall of Chevrolet Bolt models because of risks of battery fires. The agreement allows the companies to move on from an embarrassing episode and remain partners in an ongoing expansion of EV models, as David Welch reports for Bloomberg. GM has said there were 13 fires and no fatalities because of a flaw in the batteries.

No, the Costs of a Wind Turbine Are Not More than the Value of the Energy It Produces: An image being widely shared on social media shows a wind turbine on fire and says that the costs of a turbine are more than the energy it produces. This is false, based on data that is old and out of context, as Jon Greenberg reports for He classifies the false statement as a “zombie claim” because a version of it was circulating in 2019. “Every study of the lifecycle of wind turbines finds that they produce more energy than it took to produce them,” Greenberg writes. “Most analyses put the energy payback period at about a year or so.”

Inside Clean Energy is ICN’s weekly bulletin of news and analysis about the energy transition. Send news tips and questions to