5 Ingenious Solutions to Renewable Energy Storage

Before we can switch to 100% renewable energy, we need to solve the problem of storage. Thankfully, these ingenious innovators are already on the case.

If we want to tackle the climate emergency, we need to switch to 100% renewable energy as soon as possible. 

The good news is the odds of making the transition in the not-too-distant future have never looked better. The cost of renewables has fallen dramatically over recent years while public support for green energy is booming. 

Still, we can’t afford to get carried away just yet. Replacing fossil fuels with greener energy sources still has its challenges. The biggest of which is that renewable energy sources are, by their nature, temperamental.

It might be extremely windy in the middle of the night, for instance, but if no one’s awake to consume all the extra power coursing out of Dogger Bank, it’s not going to do us much good. 

The solution to this problem is storage–stockpiling renewable energy when it’s produced and feeding it back into the grid when it’s needed. 

Unfortunately, storing energy is still relatively expensive. And although the UK is experiencing an “energy storage boom”, grid-scale storage solutions are still in their infancy.  

But things are moving fast, thanks to a collection of innovative Greentech businesses that are rapidly increasing our ability to store sustainably-generated electricity. 

Here are five examples of cutting-edge tech companies that are thriving in this important space.  

Gravitricity’s gravity battery 

Of all the energy storage solutions in the works, Gravitricity’s ‘gravity battery’ might be the most elegant. 

The Edinburgh-based company has developed a unique system that stores renewable energy as gravitational potential energy, essentially by lifting a large weight into the air. 

Gravitricity’s battery takes in excess renewable energy and uses it to drive motors that pull the weight upwards like an elevator. Then, to release the stored energy, Gravitricity simply lowers the weight again, using the force of gravity to drive turbines that produce emission-free power. 

Gravitricity has already developed a working prototype of their system that can store 1200 kWh of electricity. According to managing director Charlie Blair, that’s enough energy to power an entire town. But only for a few seconds.

You can learn more about Gravitricity and its system on GrantTree’s innovation and technology podcast, What Comes Next?

Gravitricity 250kW energy storage demonstrator, Leith
Gravitricity's 250kW prototype in Leith, Scotland

OXTO Energy’s Inertia Drive

OXTO Energy’s Inertia Drive stores electrical energy as kinetic energy by spinning a mass at high speed. 

The drive is based on the flywheel mechanical battery concept, where electricity is used to accelerate a motor to speeds of up to 50,000 rpm. This energy can be syphoned off by connecting this rotating mass to a generator. 

Each drive can hold up to 7.5 kW of energy and deliver maximum power output in just four milliseconds. OXTO’s drive can be used for grid-level storage as well an on-site charging solution for fleets of electric vehicles. 

Perhaps most interestingly of all, the Guilford-based company says its inertia drive could be used by public transportation systems as a form of regenerative braking. This which recoup energy from decelerating vehicles that would otherwise be lost as heat and noise.

H2GO’s Hydrogen Sponge

H2GO is working on a unique reactor that can store gaseous hydrogen in a solid state. 

The reactor does this by trapping hydrogen in nanoscopic pores inside a flexible, sponge-like material. Once the material is heated, the hydrogen is re-released as a gas can be used in fuel cells to generate emission-free electricity. 

H2GO’s reactors can be deployed as a ‘plug n play’ solution and transported in shipping containers around the world. Meanwhile, H2GO’s AI algorithms make sure the management, storage and deployment of hydrogen energy are all handled in an energy and cost-efficient manner.

Besides its utility-scale solution, H2GO is also developing a compact hydrogen storage system the company says could increase drone flight times by as much as 300%. 

Highview Power’s CryoPower Batteries

Highview Power’s field-tested CRYObatteries use liquified air to store unneeded renewable energy. 

The technology, which was successfully used to harness waste heat from GE’s Jenbacher landfill gas engines, will utilise off-peak renewable energy to power an industrial liquefier that cools air to -196 degrees Celcius. 

To release this bottled energy, Highview Power’s system simply reheats the supercooled liquid, meaning it expands back into a gas. This expansion forces air through a turbine to produce electricity.  

Highview Power is currently constructing its first commercial CryoPower plant in Carrington, outside of Manchester. Once the facility is completed in 2022, it will be capable of storing up to 250 MWh of energy, enough to power 100,000 homes. 

Rhe Energise’s Pumped Hydro

Rhe Energise utilities a process called pumped hydro to store renewable energy. 

Like Gravitricity’s gravity battery, pumped hydro turns electrical energy into gravitational potential energy by lifting up a large weight. 

Only, instead of winches, mine shafts and solid material, Rhe Energise’s system uses low-cost renewable energy to pump ‘high-density fluid’ into storage tanks at the top of an incline. 

To release energy, the system lets liquid flow downhill again, powering turbines as it moves. 

Instead of using regular H2O, Rhe Energise will use a fluid that is 2.5 times denser than water. This will enable Rhe Energise to move liquid over a significantly shorter distance – hillsides instead of mountainsides – while capturing the same amount of energy. This will also cut down on both the cost and environmental impact of production.

Rhe Energise’s hydro systems will store between 10 and 50 megawatts of electricity, enough to power around 60 homes for a month. 

Let’s close the funding gap 

The world of energy storage is an exciting and inspiring place, populated by innovators working to make a meaningful difference to our struggle against climate change.

As always, funding remains one of the main obstacles to the development and deployment of these important technologies. And to the positive changes they could yield for our society. 

If you’re looking for funding for your own renewable energy storage or low emissions storage, we’re here to help.

GrantTree is the UK’s leading innovation funding agency, specialising in innovation grants and R&D Tax Credits. Our funding experts can help identify the various government funding opportunities open to your business and maximise your chances of applying successfully. 

If you want to learn more about your funding options, just drop us a line.

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