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Revolutionary thinking

Posted on 04/09/2017

Creating scalable, sustainable energy storage.

How OXTO Energy's flywheel could transform demand-based use.

We look at some of the rising stars of innovation who, with KTN’s support, exhibited at this year’s IdTechEx show in Berlin, which showcases the latest in emerging technologies.

OXTO Energy has developed an innovative flywheel energy storage system, which makes sustainable, low-carbon energy more viable. OXTO’s George Prassinos and Lewis Gardiner explain how.

So how does your flywheel work?

A flywheel is like a mechanical battery that stores kinetic energy in the form of a rotating mass. The problem is that we have an energy grid that was built 80-100 years ago, and was not designed for renewable sources. With renewable technologies such as wind and solar, energy generation is intermittent, it cannot respond quickly to changes in demand, and it is difficult to store the energy it produces. But with our flywheels, excess energy can be stored until it’s needed, making it much easier to use clean energy.

And is it true that this was originally designed to work in space?

Yes – OXTO is a continuation of a previous business that was working with satellite systems. One of the projects we were working on involved flywheel-based energy storage: a mechanical system that works like a battery, but that doesn’t have any chemicals in it. We realised that it could have important applications on Earth.

Presumably it still needs a vacuum?

That’s right. If you imagine you had an elevated bicycle wheel and you were to spin it, it would continue to spin for some time: effectively, it is storing the energy that you have inputted. If it’s spinning in a vacuum, it will continue potentially for ever. Our flywheels operate in a vacuum: we don’t create a perfect vacuum, but we’re close enough for it to minimise energy losses. It will continue to spin, and then when you want, you can take the energy out again.

Flywheels have been around for a long time – what’s new about your system?

The flywheel concept is old technology. It’s a simple concept, really, and our version tries to make the system as simple as possible. It doesn’t have the complex bearings of other devices – you don’t really need them. We’ve also made it as easy to manufacture as possible, with components you can find anywhere. There are no chemicals, and no magnets. Mechanically it’s simple, but there’s a lot of innovation in the system that controls the device efficiently. We partnered with the Manufacturing and Technology Centre at the University of Nottingham to develop the electronics that make it run.

What is your market for the device?

Potentially, the whole energy market can benefit: the question really is just who benefits most from using it at scale. Clearly, it benefits the people who are responsible for balancing the Grid, making sure that electricity is there when you flick a switch, by balancing generation with consumption: it means that they don’t have to rely so much on power stations burning fossil fuels, which can respond quickly to changes in demand.

And clearly it helps producers of renewable energy, such as solar farms and wind farms. At the moment, you can only store energy on a small scale: the big picture is that this might make sustainable energy generally much more feasible, and cheaper. According to some estimates, if you were to add storage to all the wind and solar in the UK, there’s already enough renewable energy being generated to supply the whole of the country.

What sort of competition do you face?

There are other manufacturers of flywheels for energy storage, based in the US. Ours is made of steel, so it is recyclable: theirs are carbon fibre, so they are more expensive. They can go quicker, but in terms of energy density for size, they’re much more expensive. Ours is simpler – fewer things can go wrong. It’s simple, and it works.

Flywheels can be small, like the ones that are installed in London buses, which store energy from braking for a few seconds, releasing it when the bus accelerates. Ours are bigger – they can supply energy for between 16 minutes and four hours, as that’s where the need is. Other competitors use lithium ion batteries, but unlike flywheels, their focus is on energy over power. Power is what you need for the Grid and utilities, compensating very quickly for all the kettles going on in a Coronation Street ad break, for example.

And is it winner-takes-all?

No, there’s not going to be just one energy storage technology that wins out – they’ll work together. We can help extend the lifetime of batteries: flywheels can deal with the first load on the Grid, and then batteries can take over. Batteries have a shorter lifetime, and they degrade. Our system is mechanical: we don’t have the chemical degradation. It lasts 25 years, which coincidentally is the same as a wind turbine.

"If you were to add storage to all the wind and solar in the UK, there’s already enough renewable energy being generated to supply the whole of the country."

What did you get from IdTechEx?

The IdTechEx event was great: it was good to meet other technology companies, get some interest, and get the company out there. We expected there to be technology companies at the Berlin event that we could potentially partner with to help scale up. But there were venture capitalists, too – we hadn’t gone there with that frame of mind. We’ve got discussions going on now around additional funding, and through another company that went with KTN, we’re now in touch with an incubator in Silicon Valley. It’s good to network and get other start-ups’ feedback on how they’ve gone about things: questions around protecting your IP, for example.

So where next?

Our biggest hurdles have now been overcome, in terms of the technology. We have a full-scale prototype of a device that is provisionally called OXTO-On, which is going through performance testing, to verify all of the individual innovations that make it up, and see how it performs in simulated scenarios. Then we have a very precise schedule for getting it to market.

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