EV automaker unveils innovative new battery energy storage system: ‘More energy extracted, longer lifetime’

The next big battery storage innovation might be coming from Eastern Europe.

Croatian electric vehicle maker Rimac announced in September that it is entering the storage sector with its highly touted SineStack system, according to a report from Energy Storage News (ESN).

This development could provide another answer to storing intermittent renewable energy more broadly. An illustration on the company website shows storage packs powered by solar panels. The graphic appears to have the packs hooked up to the power grid, therefore powering EV charging stations and also energizing a business.

Rimac Energy product engineering manager Roger Moorhouse gave a glowing debut review of the tech, set for production in 2025, during a European energy storage summit. His company’s product leverages an efficient relationship between the inverter and the battery cells. Specifically, the inverter tech is installed so the “capability is distributed amongst all of the modules, giving independent control over every 18 cells,” per ESN.

Inverters convert stored, direct-current (DC) energy into the alternating-current (AC) electricity we use in our grid and homes, according to the U.S. Department of Energy.

The new product’s distributed inverter capability “means more granular balancing, more redundancy, more energy extracted, longer lifetime, and all of that control to really make it a software-defined product,” Moorhouse said in the ESN report.

The storage capacity is billed at 790 kilowatt-hours, using lithium-iron phosphate (LFP) technology. LFP batteries are usually cheaper to make than some alternatives, in part because they use iron in the charge/discharge chemistry instead of costly nickel and cobalt, the Washington Post reports.

Regarding the capacity, Baltimore-based Constellation Energy notes that a single kilowatt-hour can power a 10-watt light bulb for 100 hours; a 50-watt laptop for 20 hours; or a 250-watt refrigerator for four hours.

A graphic Moorhouse shared during the summit lists the operating temperature of the pack at minus 4 degrees to 113 degrees Fahrenheit. He said that SineStack will have “the best cycle life in … lithium-ion” battery energy storage, at 12,000 charge/discharge cycles, before losing performance. What’s more, the storage unit is being made with over a 92% round-trip efficiency, all per the ESN report.

Round-trip efficiency is the amount of electricity added to storage that is later retrieved, according to the U.S. Energy Information Administration — the higher the efficiency, the better.

“If you’re asking how we can achieve this, it really comes back to the point that we are vertically integrated across the whole system, there is virtually no boundary between the battery and the inverter, it’s highly integrated with reduced filtering requirements, which allows us to get the best footprint (energy density) in the industry,” Moorhouse said to the group of techies in eastern Europe, per ESN.

Rimac’s innovation prowess for EVs is already impressive. Last year, its Nevera became the world’s fastest production EV, at 258 miles per hour.

Now, Rimac experts said on the business’s website that they plan to take “energy storage to the next level.”

“Sustainable power for a planet that can’t wait,” the company states online.

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