Will Battery Energy Storage Systems Be Useful in the Future?

• Porsche launches experimental battery energy storage system (BESS) from pre-production Taycan batteries, aiming to help its Leipzig plant during peak load times.

• The automaker is the latest VW Group brand to experiment with BESS, after Audi has built a similar, smaller system for its charging hubs.

• Porsche expects that demand for such systems will materialize in the future, allowing BESS to sell energy to grid customers while also acting as a grid stabilizer.

Automakers have accumulated no shortage of EV battery packs in the course of developing electric models. The prototypes and pre-production cars alike usually meet a depressing fate, but their battery packs—being the most expensive single part—are often too new to be recycled but also aren't suitable to be sold to dismantlers as used parts.

In short, there is a finite number of things that automakers can do with battery packs of prototypes that are going to be scrapped, and all of the options, with the exception of leaving them alone, are a bit expensive to undertake especially when there is a very real budget involved.

This has led a number of automakers, including most recently Porsche, to construct experimental battery energy storage systems (BESS) in the hopes of seeing some use from such systems, as part of finding ways to put them to use in a future when used EV battery packs are going to be a major problem.

Porsche's sibling brand Audi has already found one possible use for them: incorporating them into reservations-only charging hubs that are slowly gaining momentum in Europe. When used in conjunction with charging hubs, the BESS may not need all that extensive of a grid connection, using the batteries to collect power over time and then dish it out to visiting EVs.

This can reduce stress on the grid and increase the hub's ability to provide juice during peak hours, while also lowering the monthly electricity costs for the hub itself.

Porsche's foray into BESS, on the other hand, looks to explore other large-scale uses for such systems.

The automaker has taken some 4,400 used battery modules from Taycan sedans, combining them into a BESS the size of nearly two basketball courts.

The aim is to use this system to provide power to Porsche Plant Leipzig itself.

"In this unprecedented model project, we were able to combine a number of different goals, including peak load capping, optimization of self-consumption, and simultaneous participation in the energy market," said Alwin Schmid, Head of Electrical Engineering at Porsche.

This is certainly a larger-scale effort than Audi's use of battery packs as part of charging hubs, and it aims to explore automaker-owned BESS sites as small, independent grids that can supply energy when peak load occurs—a technique called "peak shaving."

If this sounds like Porsche is thinking of becoming a small power company, this characterization is perhaps not incorrect. Earlier this year Porsche parent company Volkswagen Group's energy and charging unit Elli revealed plans to build and run large-scale energy storage systems, with the largest one eyeing a 700-MWh storage capacity.

And just like utility companies, the goal is to sell energy when customers need it.

In Porsche's case its new BESS has a capacity of just 5 MW, featuring an energy content of 10 megawatt-hours. And the energy it collects is partially generated by the plant's solar panels.

This is essentially a scale-up version of a home BESS coupled with solar panels—something we were told a decade and a half ago would become commonplace by now.

"We wanted to create electricity storage capacities for the Leipzig plant in order to make the site even more economical and to increase its degree of self-sufficiency. So it was only logical to use batteries from Taycan preseries vehicles instead of recycling them," said Jonathan Dietrich, overall project manager for battery storage.

While such uses for BESS sound very logical, especially given the current cost of battery recycling, the industry has yet to make a real business case for a larger scale use of energy storage systems to the point where demand from grid consumers could generate money for automakers.

For one thing, peak loads have to be seen as a problem big enough where an automaker would actually spend the money to build an energy storage system to counteract them.

At the moment Porsche says this isn't a solution searching for a problem, and management sounds very certain about demand for such systems materializing.

"The stationary battery storage system will be integrated into the balancing energy market in every marketable form by the end of the year—including, in addition to, peak shaving, as a grid stabilizer for the upstream distribution grids," the automaker says.

Will battery energy storage systems become a common part of grid infrastructure in the 2030s, or could this happen much later, if at all? Let us know in the comments below.