The same lithium-ion battery technology that powers Tesla’s electric vehicles will be used to develop a battery for the home, according to a statement by CEO Elon Musk during a recent conference call with analysts. The batteries would be used by homes and businesses to store excess energy generated from solar panels during the day, and drawn from at night when panels sit idle.
Official details of the project are still a ways off. When we contacted them, Tesla said they’re currently not sharing any additional information about their energy storage and home batteries for several months. What Musk did reveal during the conference call was that "we’re going to unveil the Tesla home battery, or consumer battery, that will be for use in people’s houses or businesses, fairly soon." Adding that, "we have the design done and it should start going into production probably in about six months or so. We’re trying to figure out a date to have the product unveiling – it’s probably in the next month or two. It’s really great. I’m really excited about it."
As the company’s first foray into selling directly to the home energy storage market, the batteries are expected to get plenty of attention just by virtue of the attached Tesla label. And it should be an improvement from the home batteries Tesla has been quietly supplying to its sister company, the solar panel maker SolarCity, located up the road from Tesla in San Mateo, California. Those batteries are currently available in select markets within California, and only through SolarCity. The new batteries would be more widely available.
Tesla would face plenty of competition for their batteries, with names like Bosch, GE and Samsung involved. Honda has unveiled a demonstration smart home that features a rechargeable home battery, along with an electric vehicle, solar panels and geothermal heat pump, and is driven by an energy management system.
One area where Tesla might stand out is in cost. Tesla assembles its battery packs from battery cells provided by Panasonic, and is about to do it on a massive scale as soon as 2016 at its gigafactory currently under construction in Nevada. Such an economy of scale – producing 50 gigawatt-hours of battery capacity each year – is expected to push the company’s car battery costs down by 30 percent. Based on the same technology, Tesla's home battery costs should come down as well.
Home batteries have the potential to be a boon to homeowners who draw energy from rooftop solar panels, particularly those whose homes are connected to the grid via utility companies that offer variable rates that depend on the hour of day, aka Time-of-Use (TOU) rate plans. PV users typically have to draw power from the grid in the afternoon and evening when the sun wanes, which is also when a utility’s energy rates are highest. Home energy storage systems help homeowners keep costs down by drawing from the battery instead, and recharging the battery during off-peak hours.