To get off the grid with home solar, you need to be able to generate energy when the Sun’s out, and store it for when it’s not. Normally, people do this with lithium battery systems – Tesla’s Powerwall 2 is an example. But Australian company Lavo has built a rather spunky (if chunky) cabinet that can sit on the side of your house and store your excess energy as hydrogen.

It stores some 40 kilowatt-hours worth of energy, three times as much as Tesla’s current Powerwall 2 and enough to run an average home for two days. And when that energy is needed, it uses a fuel cell to deliver energy into the home, adding a small 5-kWh lithium buffer battery for instantaneous response.