BMW is making a major push into the stationary energystoragemarket.

The German automaker announced that it is turning new and used i3 batteries into energy storage solutions for homes and small businesses. The company unveiled its plans at an electric vehicle symposium in Montreal.

“With a battery storage system electrified by BMW, our customers can take the next step toward a sustainable energy lifestyle. Coupled with the home-charging and solar energy programs, the system enables BMW drivers to embrace holistic sustainability beyond e-mobility,” said Rob Healey, manager of electric vehicle infrastructure for BMW North America, in a statement.

In an interview, Healey added that energy storage fits with BMW's 360º Electric program, which currently offers customers electric vehicles, charging infrastructure and rooftop solar through a partnership with SolarCity. Through that partnership BMW i owners receive a $1,000 credit toward SolarCity's home solar offer. BMW's sustainability package sounds very similar to the type of solution Tesla wants to offer with its proposed acquisition of SolarCity.

"This is really a part of a much bigger puzzle for BMW that we’re putting together as we look out to the future," said Healey. "We offer customers electric vehicles, we offer customers charging, and we offer customers access to solar panels and producing their own renewable energy. And now, with this next piece, we offer the customer an energy storage solution that fits into the overall picture of sustainability."

The market-ready product currently uses i3 high-voltage batteries, but can be equipped to incorporate second-life batteries as they become available. There are relatively few of these used batteries on the market today, because the i3, an all-electric city car, has only been on the market since 2013. That will change as the lithium-ion batteries degrade over time and are no longer considered suitable for vehicle use. A repurposed battery can offer “many additional years of service,” according to BMW.

As i3 batteries reach the end of their automotive life, BMW and German-based Beck Automation plan to turn them into plug-and-play energy storage systems by unbolting them from the i3 and installing them in a Beck-designed charging module. The system is sized to fit conveniently in a basement or a garage where it can be used to power electrically operated devices in a home or to charge an electric car.

The energy storage units are equipped with BMW i3’s 22-kilowatt-hour or 33-kilowatt-hour capacity batteries, which are ideally suited to operate appliances and entertainment devices for up to 24 hours. A typical home in the U.S. consumes between 15 and 30 kilowatt-hours of energy per day.

The systems are outfitted with software to determine the optimal time to charge or discharge the system. The BMW storage system also includes a voltage converter and power electronics to manage the energy flow between renewable energy resources, the home and the battery.

“With this system, which integrates seamlessly with charging stations and solar panels, customers can offset peak energy costs and also enjoy the added security of an available backup energy supply during power outages,” according to the BMW press release.

Theoretically, this concept should give i3 drivers a new way to make money from their used cars by creating a market for second-life batteries. However, it’s not yet clear how a battery buyback program would work.

There are also a number of outstanding questions around battery design and cost. Tesla's 6.4-kilowatt-hour home battery sells to installers for $3,000 and is estimated to retail for around $7,000. Can BMW's 22-kilowatt-hour used battery get anywhere close to that price?

In addition, the product release timeline has yet to be determined. According to a spokesman, "BMW is currently evaluating a distribution/marketing strategy where pilot programs in the U.S. could start in 2017."

BMW has been preparing to enter the stationary energy storage market for a number of years. In 2013, the automaker installed a microgrid application at the University of California San Diego using second-life Mini E batteries. In 2014, BMW integrated high-voltage batteries into a stationary storage system in Hamburg for Vattenfall that stores solar power as a buffer for fast-charging stations. In 2015, NextEra signed a contract for the delivery of 20 megawatt-hours of repurposed automotive batteries from the i3 and BMW’s ActiveE test fleet -- which BMW claims is the largest contract of its kind in automotive history.

In addition, BMW continues to participate in an energy storage pilot project with Pacific Gas & Electric. Under the program, PG&E manages 100 kilowatts of demand from 100 active i3 vehicles and a stationary unit of repurposed BMW Mini E batteries located at BMW’s Mountain View office. The system was designed to test how electric vehicles and second-life batteries can offer reliability services to the grid. Last fall, BMW shared preliminary results showing that the system had delivered on more than two dozen demand response events called by the utility.

According to Cliff Fietzek, manager of connected e-mobility at BMW North America, past experience revealed that it's very expensive to reconfigure batteries for reuse, which is why BMW developed a plug-and-play solution for it's home battery. “We don’t have to put any special software in or take modules out and can take advantage of all of the engineering we put into producing the car battery," he said. "We can use the same heating and cooling system for the car battery and the same safety mechanisms … there is not too much work to be done on the integration side, which saves a lot on cost and increases flexibility.”

However, the company will have to wait to see the results of its home battery pilot programs before really knowing what the cost and return on investment is, he added.

BMW is the latest auto company to get into stationary storage. Tesla has garnered an enormous amount of attention with the launch of its energy storage business and massive battery Gigafactory. Meanwhile, Toyota, General Motors and Nissan are actively testing stationary storage solutions and looking to make larger plays. Daimler/Mercedes-Benz introduced a stationary battery business in Europe last year, and is rumored to be launching a U.S. product this fall.