by Samantha Page – CLIMATE PROGRESS

Tesla, beloved car manufacturer, auto industry disruptor, and brainchild of a genius, officially announced plans late Thursday night in California to offer home and business batteries to the market.

The residential battery, called the Powerwall, is available to installers in 10 kilowatt hours (kWh) or 7kWh sized at $3,500 and $3,000, respectively, and is available online now. The business version is not yet available.

In a Tweet on Wednesday, Tesla CEO Elon Musk referred to batteries as “The Missing Piece” in order “for the future to be good.”

Energy storage is seen as a key to expanding the use of renewable energy sources such as solar and wind. Without energy storage, grid operators have to put out the exact amount of electricity that people are using every moment of the day. When you flip the lights on in your house, grid operators have to make sure there is enough electricity available for you to take. When you shut off your air conditioner, they have to scale back to avoid overloading the grid.

Utilities across the country already use some battery storage to help manage the electrical grid. On a smaller scall there is also some residential and commercial energy storage on the market.

But as more and more solar and wind power enter the grid, batteries are becoming more and more important. Intermittent energy sources like solar and wind only provide power at certain times of the day. That can make it hard for grid operators to balance energy going onto the grid with energy being used. Utilities’ inability to balance production and demand is one of the biggest argument’s against increasing the use of renewable energy, but Tesla’s announcement could be a huge blow to that argument.

“Our goal is to fundamentally change the way the world uses energy,” Musk told reporters.

After turning a profit for the first time in 2013, paying back a nearly a half-billion loan from the Department of Energy, and now constructing a “gigafactory” in Nevada, Tesla is something of darling for media, business, and renewable-energy enthusiasts. Musk has been straightforward about his vision for the future, telling the Wall Street Journal last year, “the reason I created Tesla was to accelerate the transition to sustainable transport. And I made that clear to investors.”

Investors have known that Thursday’s announcement was coming for some time. In developing its flagship electric car, Tesla’s research has been instrumental in creating more efficient, more compact batteries. Putting those batteries onto the grid is the natural next step.

Musk referred to the announcement as an “unveiling,” but in fact the Tesla prototype has already been installed in at least 300 Californian homes, under a pilot program with SolarCity, a company that mainly specializes in leased, residential solar systems. SolarCity was started by Musk’s cousin, Lyndon Rive, and Musk is the company’s chairman and largest shareholder.

Musk has said that SolarCity will pair all its solar installations with battery backup within the next 10 years.

“It really is the next big thing,” SolarCity spokesman Will Craven told ThinkProgress. “It may not be long before everyone has this sort of futuristic battery in their garage.”

While there is some debate over whether it will make financial sense for many homeowners to install battery storage, there is no question that batteries are already beginning to save money and strengthen the grid in some areas. The three largest investor-owned utilities in California are required to install 1.3 gigawatts (GW) of battery storage by 2020. California has more solar installed than any other state, and solar has produced a record-breaking nearly 20 percent of the state’s power on some days.

Boosted by huge growth in solar and wind power, demand for energy storage is expected to go from 0.34 GW installed in 2012 and 2013 to 6 GW in 2017 and more than 40 GW by 2022, according to the Energy Storage Association.

In the recently released Quadrennial Energy Review, the Department of Energy called out battery storage as a necessary component of America’s energy future. Battery storage was listed as one of the United States’ “available energy sources and technologies that will help meet its climate change goals.”

Meeting climate change goals will depend largely on our ability to move away from high-emission electricity sources. The electricity sector accounts for about 30 percent of the United States’ carbon emissions — and more than three quarters of that comes from coal. The Environmental Protection Agency’s proposed Clean Power Plan seeks to limit carbon emissions from power plants, which some expect will push even greater renewable energy development.