10 start-ups powering the future of energy

18 Feb 2021

Image: © makistock/Stock.adobe.com

For a sustainable future, we need sustainable energy. Here are 10 start-ups innovating to solve this problem.

Click here for more stories from our Sustainability Week.

From hydrogen to hydropower, and from offshore solar farms to heat storage, these incredibly innovative start-ups are coming up with remarkable ideas to power our future.

Easy Hydro

Naturally, our Start-up of the Week for Sustainability Week is one that’s pioneering in the energy space. Trinity College Dublin spin-out Easy Hydro is focused on hydropower and has engineered low-cost water turbines that can be fitted to existing water pipelines. With these installed, lost potential energy from these pipe networks can be harnessed for electrical power for self-consumption or even selling to the grid.

Founders Dr Daniele Novara, Dr Miguel Crespo Chacon, Prof Aonghus McNabola and Prof Paul Coughlan had a difficult start when the early days of their start-up coincided with a global pandemic, but they adapted to the new normal and managed to get more than 30 projects going in just over a year of operation. The company is set to start raising investment within six to 12 months.

EH Group

Moving from hydropower to hydrogen power, we have EH Group, founded in 2017. As a potential clean energy source, hydrogen is dogged by expense and complexity. Swiss start-up EH Group, however, intends to make hydrogen energy compact, reliable and low-cost.

In March last year, the company was awarded a grant from the EU’s Horizon 2020 accelerator programme for a two-year project focused on commercialising its fuel cell technology with an overall budget of €2.1m.

Co-founder and director Mardit Matian believes EH can deliver hydrogen fuel cells that could be used in stationary applications such as commercial buildings and data centres, as well as in mobility and transport such as buses, trucks, trains and ferries.

Energy Vault

Also headquartered in Switzerland is Energy Vault, which is aiming to enable a renewable world by making batteries based on physics, not chemistry. This involves building huge towers of weighty bricks using surplus energy from a renewable source such as a solar farm to power the cranes. This potential energy is stored until Energy Vault’s software tells the system to lower the bricks, which spins generators that send electricity back into the grid.

The company raised $110m from SoftBank in 2019. It was one of Fast Company’s 2019 World Changing Ideas Awards winners and was named among the World Economic Forum’s Technology Pioneers of 2020. Earlier this month, co-founder and CEO Robert Piconi was interviewed for BBC’s People Fixing the World podcast.


UK start-up HiiROC is another innovator in the hydrogen space. Its focus is the production of hydrogen from the methane and biomethane of current gas networks through a unique plasma-based process. The hoped-for end goal is much the same as EH Group: an energy source that is low-cost and emission-free. The smallest of HiiROC’s units is about the size of two refrigerators, so the company sees its offering as scalable and flexible.

At the start of the year, it was among 10 start-ups selected for the ATI Boeing Accelerator. This three-month programme supports start-ups in the UK’s aerospace ecosystem, marking HiiROC’s potential to bring clean energy to this industry.


German start-up Kraftblock has been noted by Sifted, climate-conscious investor Erik Kobayashi-Solomon and now Siliconrepublic.com as a start-up to watch in 2021. It’s also a recent addition to the Koolen Industries portfolio, after receiving a €3m investment from the Dutch clean energy conglomerate last year.

Founded in 2014 by Dr Martin Schichtel and Dr Susanne König, Kraftblock uses nanotechnology to develop new ways to store and transport energy as heat. The high-temperature storage systems it manufactures can effectively store temperatures of up to 1,300 degrees Celsius thanks to a patented nanotechnology granule. This storage system comes as modular containers, meaning it can have applications in mobility and transport as well as in buildings.


Back in Ireland, Cork-headquartered Nexalus was founded by Kenneth O’Mahony, Dr Cathal Wilson and Dr Tony Robinson. Guided by thermodynamics, thermal-fluid science and clever engineering, Nexalus develops systems for extreme-heat-producing electronics, which help to cool, capture and reuse this thermal energy. The electronics that can make use of these products range from gaming systems to high-performance computers, bitcoin mining systems and data centres.

With its products, Nexalus aims to help businesses reduce their overall energy usage and CO2 output by up to 50pc. The company has been recognised as a high-potential start-up by Enterprise Ireland and Robinson was awarded Inventor of the Year at the 2019 Trinity Innovation Awards.

Oceans of Energy

Dutch start-up Oceans of Energy aims to bring affordable clean energy to densely populated areas and islands with limited space through its offshore solar energy systems. The company’s first durable floating system was put to the test in the Dutch North Sea, 12km off the coast of The Hague, where it survived storms and extreme winter weather and was generating 17kW of energy by January 2020.

And it’s not just energy these offshore solar farms can generate. Oceans of Energy is already exploring multiple uses for its offshore facilities through a partnership with The Seaweed Company to farm seaweed at these sites.


Founded in 2018, German start-up Poligy is another on our list trying to harness the potential of heat energy. The company says its patented waste heat recovery system can achieve 4pc to 15pc conversion efficiency of waste heat into electricity with relatively low costs.

Poligy’s system uses bipolymers, which are two-ply plastic strips that contract and expand depending on the temperature. This movement can be used to power a wheel or belt to generate electricity. Able to work at temperatures between 50 and 150 degrees Celsius, Poligy sees its bipolymer solution put to work in thermal engines and solar modules.

The technology is being used in a BipolymerEngine project as part of the EU’s Life programme, which supports environmental, nature conservation and climate action projects.


UK start-up RheEnergise already has a roadmap for the coming years, with plans to have its first commercial hydropower energy storage system operational by 2024 and more than 100 systems following that in the next decade.

Tipped as ‘Britain’s ultimate renewable power source’, RheEnergise is bringing innovative energy storage underground. From buried storage tanks beneath a hill, its system pumps a proprietary fluid up to storage tanks at a higher elevation. This dense liquid then flows back down the hill, turning turbines that regenerate electricity that can then be supplied to the grid.

Earlier this month, the company announced a major partnership with Eminox, a manufacturer of complex emissions reduction systems.

VorTech Water Solutions

Last but not least is VorTech Water Solutions, a start-up that spun out of NUI Galway in 2019. VorTech specialises in providing energy-efficient water and wastewater solutions, with the aim of reducing the massive energy footprint of wastewater treatment.

According to VorTech, treating wastewater consumes about 2pc of the world’s electricity, but it claims to have a solution that can save on energy with no downtime. The founding team – which includes Dr Sean Mulligan, John Geoghegan, Dr Eoghan Clifford, Alan Carty and Peter Leonard – uses expertise in computational fluid dynamics and process modelling to maximise treatment performance at the lowest energy input, developing a solution that can reduce the cost of aeration by up to 50pc. The company has also explored the potential of using its technology in aquaculture and salmon farming.

A recent winner at the Irish Times Innovation Awards, VorTech has also been recognised as a high-potential start-up by Enterprise Ireland.

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Elaine Burke is the host of For Tech’s Sake, a co-production from Silicon Republic and The HeadStuff Podcast Network. She was previously the editor of Silicon Republic.