From sea to land: REMORA, the solution that will finally enable renewable energy to be stored

Although renewable energies have been growing steadily for several years, their availability remains dependent on random and unpredictable weather conditions. Storing renewable energy efficiently has therefore become a crucial issue. To meet this challenge, SEGULA Technologies has developed a high-efficiency, flexible, robust and sustainable energy storage solution based on isothermal air compression: REMORA.

Initially designed for the marine environment (REMORA offshore), the technology, now patented in some twenty countries, has evolved into REMORA Stack, a mass storage solution for industries and commercial areas, and REMORA Home, a smaller-scale version for private individuals.

REMORA Offshore: technology initially designed for the marine environment

The first version of REMORA, now called REMORA Offshore, was conceived and developed in 2014 to exploit the advantages of the marine environment for energy storage.

Suitable for most coastlines around the world, this initial version consists of a floating platform and submerged tanks. The principle is simple: electricity generated by offshore wind turbines (or another energy source) is used to pump water, which is then used to compress air. This compressed air is then stored in underwater tanks, which maintain a stable temperature and pressure to prevent any loss of energy in the form of heat. When energy is needed, the compressed air is released and converted back into electricity, ensuring a continuous supply even when there is no wind or sun.

This architecture laid the technological foundations that subsequently enabled the miniaturisation of REMORA and its adaptations for other uses.

Towards REMORA Stack: energy storage for industrial applications

‘For seven years, we focused on offshore energy storage,’ explains David Guyomarc’h, REMORA project manager in the Research and Innovation department at SEGULA Technologies. ‘But the closer we got to the industrial perspective, the more it seemed appropriate to refocus the project on a more compact version of the system. And as we miniaturised and optimised the system, we needed less and less water.’

And so, in 2021, the REMORA Stack project was born, based on the same isothermal air compression technology as REMORA Offshore, but on the surface and in a format more suited to the specific needs of sites requiring energy autonomy (industrial sites, public infrastructure, shopping centres, eco-neighbourhoods, electric parks, etc.). The objective remains the same: to maximise large-scale self-consumption of green energy.

Here, underwater tanks are replaced by standard containers measuring 12 metres long. They store excess energy in the form of compressed air, which can be released later to generate electricity.

One of the major advantages of REMORA Stack is its modularity: adding containers allows manufacturers to increase storage time without having to replace the compressor, which promises significant savings.

REMORA Stack is currently being developed as part of the Air4NRG collaborative project, funded by the European Union. The first full-scale prototypes will be produced and installed in Spain to fine-tune the technology and validate its performance, before preparing the first series in 2027 and large-scale industrialisation by 2029.

REMORA Home: energy storage for private individuals

But the potential applications of REMORA technology don’t stop there! While photovoltaic solar panels are becoming increasingly popular with private individuals, SEGULA is also working on a smaller-scale domestic storage solution: REMORA Home.

Compact, about the size of a refrigerator or water heater, REMORA Home will enable individuals to store excess energy produced by their solar panels or other renewable sources for later use, and to manage their consumption using a dedicated app.

For this system, compressed air is stored in much more compact cylinders similar to diving cylinders, measuring 1.80 metres long and 20 cm in diameter. With these dimensions, 10 cylinders will store approximately 12 hours of energy. And if the user wants more autonomy, they can simply add more cylinders according to their needs.

Practical, sustainable and environmentally friendly, this solution could one day compete with lithium-ion batteries

In addition to offering high efficiency and great flexibility to users, its minimum lifespan is estimated at 30 years (compared to an average of 10 years for other batteries). As with other versions of REMORA, its overall efficiency is 70%, which means that 70% of the energy used to compress the air is recovered in the form of electricity during the discharge phase. This rate is comparable to that of the best batteries, while avoiding the use of rare and polluting materials.

Tests on a pilot house will take place in 2026 with the aim of verifying the technology’s effectiveness in real-world conditions and preparing for its industrialisation.

And what about the cost?

‘It’s still a little early to determine the exact cost to individuals,’ says David Guyomarc’h. Our goal is to offer a solution that is cheaper than batteries for equivalent installations, while providing longer storage capacity and a longer service life. Today, installing storage at home is not so much about optimising your bill economically, but rather about making it less sensitive to technical uncertainties in the grid or political and economic fluctuations in the market.”

💡 The REMORA system has been designed to adapt to all types of tanks, as all the technology is contained within the compressor. Thanks to this modularity, REMORA can store compressed air in small cylinders suitable for homes as well as in large containers intended for energy infrastructures or local authorities.

 

One of the major advantages of REMORA technology is its flexibility and non-polluting nature. Unlike other energy systems, it does not use any sources of pollution or chemicals. Air and water are used to operate the system and are released without any alteration.