As predicted by the majority of industry insiders, billionaire entrepreneur Elon Musk’s much-hyped announcement last month was about the creation of a new type of battery by his company Tesla.

While unveiling the Tesla Powerwall unit at his company studio just south of Los Angeles, through a newly created business arm called Tesla Energy, Musk laid out his vision for the creation of a ‘clean energy ecosystem’ that is not reliant on fossil fuels. He spoke of huge demand for his batteries from industry, which could eventually see the creation of custom battery packs for businesses, utilities and consumers.

The Powerwall is a stationary battery designed to power homes alongside the existing electricity grid. The 10kWh version works as a back-up power source in case of a power cut, while the smaller 7kWh model is optimised for daily use. Both units can run off solar power and are able to store surplus energy for use at night.

The Tesla Powerpack, an industry-based application of the same technology, aims to deliver 100kWh of capacity. With his cells able to stack together to produce huge sustainable power sources, Musk hopes to interest businesses and utilities with bespoke energy solutions in the coming months and years.

As with the man himself, Musk’s new battery has divided opinion. While some talk of a game changer for clean energy, others dismiss the Powerwall as a toy for the rich that does not solve real-world energy problems.

Critics have questioned the announcement from a range of angles. How will a battery that utilises pre-existing lithium-ion technology change the face of energy storage as we know it? Will the cells really be able to perform weekly and in some cases daily cycles for long enough to justify their purchase and installation? Are Musk’s claims of how much energy will be generated and money saved for households all they are cracked up to be?

It is clear to any objective observer that much of Musk’s rhetoric speaks of a distant future that is not yet just around the corner. While 65% of the US’s electricity is generated by coal and natural gas, with only 10% through renewable energy sources, Tesla Energy is powerless to deliver its ‘clean energy ecosystem’ with some new batteries.

Nevertheless, Musk deserves credit for moving the renewable energy storage discussion into the mainstream and for putting forward his own ideas for a solution.