Solar power and new tech drive world first for the railways

Posted on: 21/08/2018

The Renewable Traction Power project team have invented a bespoke piece of technology that will enable railways to run directly off solar power.

KTN’s Complex Systems team has worked with a wide range of companies to help them combine systems and signpost them to Innovate UK funding. Some of the most notable examples have been highlighted in a series of case studies which will be published over the next ten days.

Complex Systems covers the key application areas of space, robotics and autonomous systems, data analytics and defence and security, with a focus on engineering best practice for systems, intelligent applications and large-scale infrastructure. KTN’s interests are in the scalability, adaptability, resilience and security of these systems.

The pioneering consortium looking into the possibility of running railways directly from solar power have made exceptional progress in their feasibility study. With funding from Innovate UK’s Energy Game Changers competition, 10:10 Climate Action, the carbon-cutting experts and project lead, alongside leading academics from Energy Futures Lab at Imperial College, London, have demonstrated that with the development of new technology, railways can effectively run directly off solar power. Their new model of power generation, storage and supply on the railways will be a world first.

The equipment works on direct current railways, which account for about one third of electrified tracks in Britain, over 3000 miles, so the potential is huge. Trains don’t come all the time, and the sun doesn’t shine for 24 hours a day, so the solar system works best with a battery that can store the solar power when the trains aren’t using it. Then when it gets dark, the solar power stored in the battery can still power trains.

The feasibility project team also includes Community Energy South, who peformed a land constraints anaylsis and identified potential development land for solar farms, and Turbo Power Systems, who specialise in the design and manufacture of auxiliary power converters and battery chargers for the rail industry and distributed generation systems.

Overcoming challenges

The team were determined to find a solution to their solar powered railways concept, but set out with some challenging tasks that included overcoming the problems associated with unsubsidised solar power generation, designing a bespoke converter for solar to be able to connect into substations, finding a suitable storage solution, and understanding the potential scale of their overall market.

Leo Murray is the co-founder and director of strategy at 10:10 Climate Change, and project manager for Renewable Traction Power. He says:

“The idea originally came from Repower Balcombe’s technical director, Tom Parker, and It was while I was talking to professor Tim Green, director of the Energy Futures Lab, that we realised the concept of feeding solar power directly to the railways had possibly never been looked at seriously before. As an engineer, Tim was concerned that there may be too many barriers to overcome, but at the same time it represented an interesting challenge, and if it could work, then it had the potential to be a fantastic solution to power railways on a much larger scale. It’s the perfect solution in the UK where distribution networks have already reached their thermal and voltage maximum, and in other parts of the world where the local grid has limited capacity.”

The project clearly highlighted many challenges, mostly of a technical nature, but one of the major successes that came out of the study, thanks to the hard work and expertise of Turbo Power Systems, was the successful design of the converter required for direct solar power supply.



Working towards a better future

There are still some challenges for the solar railways to be fully realised, including new product development and acceptance for use on UK railways, as the equipment doesn’t actually exist yet, and the integration of new technologies on the traction power network, which requires external funding before it’s at a readiness level for the mass market. Contractual complexity and public sector procurement may cause problems too, where previously single large suppliers will be replaced by multiple small renewable operators. Additional costs, such as insurance for third party equipment operators may make operational costs more expensive, and rigid safety rules governing trackside work may hinder the installation and maintenance of the solar assets in the ideal trackside location. Mindful of these constraints, Leo says:

“Solar traction power is technically feasible and commercially attractive, and there are movements now to take our ideas a step further. We’ve identified some excellent opportunites here and also abroad, where the potential is even greater, given the amount of sunshine and a lesser degree of seasonal variance than the UK.”

Community Energy South and 10:10 are now working with Network Rail’s route asset management team for Wessex to develop a small portfolio of pilot projects to connect to their network. NR have committed substantial resource to progressing this, including work to identify existing power electronics in use on the railways already which could be repurposed for connecting solar to traction networks. They are also now working on a solution to allow solar to be installed on NR’s own land, maximising the financial benefits of renewable traction power to Network Rail.

Turbo Power Systems have just secured funding for their role in a Horizon 2020 funded project called E-Lobster, which is looking at better integrating electricity distribution networks with rail traction systems. This programme will include developing an inverter design for directly connecting renewables to electrified rail. Further to that, 10:10 is working with Energy Saving Trust in Wales to identify opportunities for decentralised community wind and solar projects to pick up some of the new electrical load which electrification of the Bristol-Cardiff route will bring to the region south of Newport.

For developments slightly further afield, a project team at the European Investment Bank is developing an internal proposal for a dedicated fund for rail electrification in developing nations as a result of our feasibility study. And finally, senior directors at the UN Development Programme partnership with India Railways, who are working to deploy solar on their property portfolio, are bulidng on the learnings of the Renewable Traction Power study and are now carrying out their own feasibility study on the potential for using solar PV generation to directly power trains in India.

Decarbonisation, renewable energy targets, and reduction in costs

By completing their feasibility study, Leo and his team have demonstrated that connection costs for renewable traction power would be competitive already and it would be cheaper for rail companies than grid supplied power, even at today’s prices. Certainly, the costs involved in a long-term solution would be far more commercially attractive than the expensive upgrades required for connecting new generating capacity to existing grids.

The team can also be confident that their work will achieve their aims of leading to substantial improvements in decarbonisation and recongisable inputs into achieving renewable energy targets and the reduction of operating costs for railways. They also plan to deliver services via a network of community owned solar farms, promising further social benefits to an already praiseworthy project. With community owned solar farms, commuters and communities would have the chance to take a direct stake in their own low-carbon future.

Leo concludes:

“With the withdrawal of subsidy support for decentralised renewables like onshore wind and solar in the UK, we must continue to innovate to maintain our leadership in this transition. If we can realise this world first opportunity, we can transorm the way electric trains are powered and make a major contribution to global efforts to tackle climate change.”

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