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A Hydrogen Fuel Tank for the Future of Communications

Thu, 22 October, 2020

TWI has been working with Stratospheric Platforms Limited (SPL) to provide bespoke hydrogen testing capability and materials performance assessments, aiming to support the testing and certification of a fuel cell power system for aircraft. To date, TWI has supported SPL with both permeation testing of their materials using helium and also thermal cycling materials over the range of liquid nitrogen temperatures to well above ambient. This has involved designing and commissioning specialist equipment and running test programmes. This work, supporting the development of materials, is ongoing.

SPL are working with a number of companies across the UK and Europe to deliver a hydrogen powered, remotely piloted aircraft that will operate in the stratosphere to deliver improved 4G and 5G coverage. The aircraft will offer a more cost-effective solution than terrestrial masts, although the system will be integrated with the existing networks. This new system will also offer rural broadband connectivity and greenfield mobile network services in unserved areas.

TWI is supporting the development of the liquid hydrogen tank and aiming to install a high altitude fuel cell testing facility, which will be the first of its type in the UK.

Speaking on the project, Richard Deakin, Chief Executive Officer of SPL, explained, “We have operated for the last five years under the radar to ensure that we significantly de-risked the project before revealing SPL to the world. With our key partner, Deutsche Telekom, who has today completed a world’s first proof of concept trial on our behalf, that moment has come. Together with Deutsche Telekom, we are looking forward to transforming the quality of the terrestrial and fixed line communications experience for many poorly-served customers using 4G and 5G from the sky with key benefits that distinguish it from all other competition at around 1/3 the cost of terrestrial masts. We will be working with our partners and others over the next few years to bring this to operational deployment around 2024.”

The high altitude communication platform has a 60-metre wingspan but weighs just 3.5 tonnes and is powered by a hydrogen fuel cell system that combines liquid hydrogen and oxygen into electrical energy with water vapour being the only waste produced. This environmentally-friendly solution offers several benefits when compared to satellites, including:

  • Being able to provide direct connection to standard consumer devices
  • Able to provide the “low latency” essential for 5G services.
  • The hydrogen power system provides coverage equivalent to around 500 terrestrial cells, enabling near 100% high quality coverage over an area up to 140km in diameter
  • Higher power, broad beam patterns and low data transmission rates compared to satellites
  • Capable of being deployed incrementally and in a modular fashion, allowing for cost-effective deployment

TWI are pleased to be able to support SPL in revolutionising telecommunications by offering materials support and bespoke advanced testing capabilities. It is hoped that, as the project continues, TWI will continue to work closely with SPL to develop hydrogen fuel cells and provide further test capabilities to support the needs of future flight.

For more information please email:


contactus@twi.co.uk