Subsidy-free solar generation connected directly to railways could supply a significant share of the electricity needed to operate Britain’s trains, a new study has found.

The research, which was carried out by Imperial College London’s Energy Futures Lab and the climate change charity 10:10, examined the potential to bypass the power grid by linking solar panels directly to railway substations using custom electronics.

The report found that solar arrays and integrated energy storage devices could supply around 10 per cent of the annual power requirements for the UK’s direct current electrified rail routes, which tend to be more common in urban areas. Crucially, they could do so at a lower cost than electricity supplied via the grid today.

According to the study, connecting distributed renewable generation to alternating current rail routes – which are more prevalent outside towns and cities – is also “a promising possibility” and should be explored.

“I believe that decarbonising our transport sector is key to meeting the UK’s climate targets,” said Energy Futures Lab director and academic lead Tim Green. “The Renewable Traction Power project demonstrates that we can harness solar to help make this a reality for our train network.

“This project also demonstrates that the best way to tackle many of the issues we face is through collaboration and leveraging expertise from a wide range of partners.”

The commuter rail network to the south of London was identified as having the most to gain from directly-connected subsidy-free solar.

The report said around 15 per cent of the power needed to run trains on these routes could be met by installing 200 small-scale solar farms alongside rail lines.  Analysis by project partner, Community Energy South, showed there are around 400 suitable sites in the region.

Small-scale solar farms could similarly supply 6 per cent of the electricity used by the London Underground and a fifth of the electricity used by the Merseyrail network in Liverpool.

The Renewable Traction Power project was funded by Innovate UK through its Energy Game Changers programme.

The project partners, which also include technology supplier Turbo Power Systems, are now seeking additional funding to develop prototype electronic equipment and prove the concept with six to ten community-owned pilot projects along rail lines in the south east of England.

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