Liquid air batteries? If you're not getting excited you should be!

If we're to have any chance of building back better, green tech will need to be at the forefront of any recovery. This is especially true in the area of energy storage. To deliver the net zero carbon system needed to avoid a climate catastrophe, intermittent renewables like wind and solar must replace fossil fuels. But there is a challenge here evident in the word 'intermittent'. Given we can't make the weather sunnier or windier on demand, how do you increase energy supply when there is a spike in demand?

This is where storage comes in: taking excess energy from a sunny day and saving it for use on a grey one. Because without this capability, we will never escape the need for carbon emitting fuels to fill the gaps (or nuclear, which though theoretically 'clean' remains fraught with issues).

Currently there are only two viable 'green' options for renewable storage. And one of these only works for hydro as it requires a mountain with a lake at the top. The other is chemical batteries. These will definitely play a key part in any transition to a zero-carbon world. But even though prices are plummeting, batteries have limitations in only being able to store relatively small amounts of electricity for short periods. And in a way that's cost intensive and inflexible when it comes to scale.

Considerations that are particularly important if our own businesses are to ever become sustainably self-sufficient in terms of energy production and use.

Which is why liquid air batteries are such an exciting development, presenting a not just viable but potentially better alternative both to batteries and other solutions currently in development; a genuine step-change innovation that solves the intermittent storage problem in a safe, cost effective and scalable way. It's British too, which is nice.

Developed by Highview Power, the first storage facility (being built in Manchester.) is due to go live in 2022, and will provide enough power to keep 200,000 homes going for five hours. This dwarfs the 30,000 homes powered for an hour by Tesla's battery park in South Australia, the biggest chemical battery system currently online (Elon backing the wrong horse maybe!). Further sites are in development in the UK, continental Europe and the US.

The process itself is relatively straightforward. Excess energy is used to chill air to a liquid which can then be converted back to gaseous form to drive power-generating turbines when needed. Base conversion efficiency is admittedly a bit below that of hydro and batteries, but this can be improved significantly if collocated with industrial plants that produce waste heat and coolant.

More importantly though, is the flexibility, scalability and relative affordability that liquid air offers...

• Air, by definition is widely available and free to use;

• It's easily storable in its stable liquid form (e.g. vs. compressed air);

• A plant can be located anywhere within reason;

• And can be constructed using established, off-the-shelf equipment;

• All easily scalable to deliver a storage solution that can power anything from 1000 to 200,000+ homes (or the equivalently sized industrial plants).

All in all, an exciting innovation that we should be looking to embrace and nurture.