Energy storage: making 100% renewable power a reality

Right this very moment, teams of ‘flex-perts’ are hard at work putting batteries at the service of the green energy revolution; bringing the benefits to ordinary people up and down the country.

What exactly is energy flexibility?

To give a bit of background, our electrical grid must always be ‘well balanced.’ If there isn’t enough energy being pumped in to meet demand there can be power cuts, and if more energy is pumped in than is being used up it can damage grid infrastructure.

Yet wind and solar energy is also ‘intermittent.’ We can’t say for sure when the wind will blow or the sun will shine; we can’t just ‘turn on’ renewables whenever we want.

On some especially windy days we already have far more wind power than we need, and we actually have to pay wind generators to ‘turn off’ in order to protect the electrical grid. It’s an utter waste of low-carbon power, especially given that when energy demand peaks (usually between 4-7pm in the evening, when the sun is low) the grid often has to ask generators to burn more fossil fuels to keep up.

So there’s the central challenge of the energy transition: if we can no longer rely on turning large, dirty generators on and off to match our ever-changing energy demand, then flexibility is going to have to come from somewhere else. Only then can we smooth the sun and wind's spiky, erratic power into a stable, controllable, 24/7 supply.

Is energy storage the answer we've been waiting for?

But that’s not all. Given that games at Arsenal happen relatively infrequently, the Arsenal battery can fill up on green energy, and then send it back to the grid to give neighbouring homes cleaner energy whenever the UK is in danger of being ‘short’ of energy.

Here then, we’ve managed to find another way to unlock ‘flexibility.’ By storing renewably generated electrons when they’re available for use later on, we now have a way to ‘call on’ green energy when we need it. In other words, energy storage devices like the one Octopus helped install at Arsenal allow owners to get paid to help make renewables work on a huge scale.

Writing in Utility Week, Lucy Yu, who heads up Octopus' Centre for Net Zero, explains that flexible energy projects like the Arsenal battery are 'indicative of what a future energy system may look like', showing the 'potential to harness existing infrastructure, especially in urban areas.' One option would be set up a 'direct wire', with assets like these operating as virtual power plants for local housing and communities. Still, Lucy argues that projects like these are put to better used serving 'the wider local energy system', as the Arsenal Battery does currently.

In the near future, we might well see other ways of storing energy come to the fore -Octopus and RES have recently pledged to invest £3bn in developing ‘green hydrogen’ over the next decade, some of which will be used to explore ‘green hydrogen storage’.

Unlocking unparalleled flexibility

Kraken currently controls hundreds of batteries across the UK - enough to store 1.2GWh of power: that’s as much storage space as in half the UK’s total 350,000 Electric Vehicles. To give a concrete example of what they do, at half-time during the momentous Euro semi-finals, the Kraken team anticipated a massive nationwide tea-break and so unleashed their batteries, sending enough stored power to the grid to address half of that extra demand.

As it stands, smart energy schemes like those enabled by Kraken could save the UK £8bn a year by making the most of cheaper, greener renewable energy and reducing the need for expensive infrastructure updates, according to the National Infrastructure Commission.

How can I get involved?

It’s not all huge companies and big batteries doing this stuff. Right now, people like you and me are mucking in, using in-home flexibility to support renewables and saving huge cash to boot. Kraken's team are working to make this a part of everyday life, so that in the near future, your home and car can make you money without you needing to do anything at all!

In fact, thousands of Octopus Energy customers are already living in futuristic flexible homes thanks to home batteries and EVs, storing and discharging energy in much the same way that Arsenal are. In doing so, they’re laying the blueprint for a second massive, decentralised network of smaller, smarter in-home batteries.

Early analysis suggests that if the UK’s EV’s were all plugged in at the right times, they could store renewables with enough capacity to meet a whopping half of the UK’s energy needs.

In the near future, the boffins at Kraken expect that they could even group the batteries in people’s homes (and electric vehicles) together, which would allow these customers to get paid even more for providing a coordinated, local, data-driven flexibility service.

What’s next for flexibility?

So there we have it. Energy storage, renewable electrons and flexibility go together like three peas in a very green pod. Early pioneers are already saving hundreds by using energy and batteries flexibly at home and flexperts like the team at Kraken are working to make energy storage and flexibility a part of everyday life in the near future. By allowing us to store green electrons (that might otherwise go to waste) for use later on, batteries are unlocking the flexibility we so desperately need, paving the way for a world that can finally be powered entirely by zero-carbon solar and wind energy.