Major technology company stuns industry with breakthrough new energy-storage system — here's how it works

A Shanghai battery maker's latest grid-storage power pack apparently commanded attention at a tech exhibition held in the city in September, according to multiple reports.

Envision Energy's battery has a density of 541 kilowatt-hours per square meter, which leads the industry, per a PV Magazine story on the Electrical Energy Storage Alliance Energy Storage Exhibition, and the unit itself can pack 8 megawatt-hours of power total within a standard 20-foot container.

For comparison, other companies have been pushing 6 megawatt-hours in a 20-foot container, with 4-5 already considered to be a high range.

"We made a huge jump from … our previous generation products," an unnamed company representative said in the PV article. "We did this to lower the cost on the system level."

In addition to huge energy density — used to hold loads of intermittent renewable electricity for later use — the power pack checks some other impressive boxes, as noted by PV. The biggest might be a clutch 96% "roundtrip" efficiency. That's the amount of stored energy that is retrieved later, according to the U.S. Energy Information Administration.

The pack also has a lifetime of almost 16,000 cycles using lithium-iron phosphate, or LFP, chemistry. LFPs are considered by many experts to be the battery science of the future. It was heralded by Forbes last year as "the next big thing" for powering electric vehicles. Better safety and cheaper materials, including iron, are noted among the perks. Lower energy density has typically been a sacrifice, all per the report.

But battery experts working on both EV packs and grid storage units seem to be making progress in addressing LFP limitations. Envision's cells are made by Japan's AESC. PV reported that Envision owns a majority of the tech company.

The liquid-cooled unit is housed in a 20-foot storage container, weighing 55 tons. Artificial intelligence helps to manage the system, all per PV.

"It managed to achieve the latest breakthrough in capacity due to a combination of factors, primarily its large capacity cells, but also system integration, compact design, and further optimization within the container," the online publication's Marija Maisch wrote.

Grid storage is becoming an important part of energy systems as countries work to reduce heat-trapping air pollution, linked by NASA and medical experts, respectively, to increased extreme weather and health risks.

Tesla last year announced plans to ramp up lithium-ion Megapack production by thousands of units. The batteries are typically deployed in groups to store massive amounts of power, according to Tesla.

Smaller versions, like Tesla's Powerwall, provide homeowners with a way to store rooftop solar energy, even deploying excess electricity back to the grid for a profit when part of a virtual power plant. And competition in home-based storage is on the way, including from Ampere.StoragePro, developed in Germany.

PV reported that Envision makes its own inverters, battery management systems, and other crucial tech. And Lei Zhang, the company's CEO, is bullish on the potential.

"The old energy paradigm is breaking down and will be replaced by a new era of energy," he said on the company website.

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