There are few more fascinating figures in business today than Elon Musk, the PayPal co-founder who has gone on to specialise in attention-grabbing transformative technology, whether it be private space exploration with Space X or highly desirable electric cars with Tesla. There's a good reason he is often compared to Iron Man's Tony Stark or a suave Bond villain.

But there is every chance Musk's biggest long-term impact will come from the announcement of a more prosaic technology – batteries. On April 30th, Musk launched Tesla Energy, a Tesla subsidiary selling large lithium-ion batteries designed for homes and businesses. The concept is simple – the seven or 10kWh Powerwall for $3,500 or the 100kWh Powerpack for $25,000 are wall-mounted batteries that store energy, whether generated onsite through solar panels or wind turbines, say, or stored at off-peak times for use during peak hours.

For a homeowner seeking to maximise the utility of their solar panels or exploit day/night pricing arbitrage, the Powerwall could be a game-changer. For businesses that require constant energy supply and for whom diesel generators are too cumbersome, the Tesla batteries are an obvious and desirable solution. Ultimately, the Tesla Powerwall, or at least domestic battery technology, could transform the energy grid, helping to solve the inconsistent supply problem inherent in renewable energy.

Musk is probably the most ambitious person on the planet, seriously proposing "hyperloop" tube-based public transportation systems and human colonies on Mars. It's no surprise, then, that he managed to depict the humble battery as playing a critical role in saving the planet from carbon emission-caused catastrophe. "Tesla energy," he said, would bring about a "fundamental transformation of how energy is delivered across Earth". Clearly, this isn't about becoming a 21st-century Duracell, this is about changing the world's energy-consumption patterns.

His vision for domestic battery energy storage is typically compelling. “What we’ll see is something similar to what happened with cell phones versus landlines, where the cell phones leapfrogged landlines, and there wasn’t a need to put landlines in remote locations,” he said at the launch. “People in a remote village or an island can take solar panels, combine it with the Tesla Powerwall, and never have to worry about having electricity lines.”

‘Super viral’

At an earnings call last week, where Tesla announced a first-quarter loss of $154.2 million, Musk was palpably excited about the new storage business, revealing the firm has already received orders for 38,000 home batteries and 2,500 utility-scale batteries; “it seems to have gone super viral” he said of the launch.

In some ways, the move into the battery-selling trade can be seen as a byproduct of the core Tesla motor business – all those futuristic electric cars require big batteries for reasonable mileage, and to that end Tesla has quickly become the world's foremost big battery company. The in-construction 10-million-square-foot Gigafactory in Nevada will be easily the world's largest lithium-ion battery-production facility when it opens in 2017, producing 35GWh of battery power annually by 2020, which is more than the entire world's battery-producing capacity just two years ago.

But rather than being seen as a byproduct, quite possibly Musk is flipping the company on its head with the launch of Tesla Energy – not a car-maker that uses batteries, but a battery-maker that also happens to make cars. At that conference call, Musk acknowledged that energy storage could become a bigger part of Tesla than the car business.

That outcome will be determined by a number of different factors. First of all, the price of lithium-ion battery production is plummeting, transforming energy markets. As technologist Ramez Naam has written: “The cost of batteries is plunging fast. Tesla will get that 2x price reduction within 3-5 years, if not faster.” At that point, Naam suggests: “Storage of electricity in large quantities is reaching an inflection point, poised to give a big boost to renewables, to disrupt business models across the electrical industry, and to tap into a market that will eventually top many of tens of billions of dollars per year, and trillions of dollars cumulatively over the coming decades.”

Rather different

That’s a big and growing market over the next few decades, whereas the outlook for automobiles on a similar timescale is rather different – the future of urban design will increasingly focus on catering to pedestrians and public transport rather than vehicles, as the current model of traffic jams full of single-passenger vehicles is essentially unsustainable. That shift will be facilitated with smartphone technology improving the efficiency of car-sharing services and public transport – why should millions of people own cars when dramatically fewer can share them, much like urban bike schemes? All of this is without considering how self-driving cars will change the industry. The age when everyone aspires to car-ownership might only have a few more decades left.

Of course, it's possible this was all part of Musk's masterplan all along – after all, he named the company after the great Serbian inventor Nikola Tesla, a pioneer in the field of electricity, not cars.

Describing a dramatic cut in carbon emissions, Musk said: “That’s the future we need to have, and the path I’ve talked about, solar panels and batteries, that’s the only path I know that can do this, and that’s something that we must do, that we can do and that we will do.”

Tesla, one feels, would approve of such ambition.