Distributed solar could power 10% of UK rail network: Imperial
Solar PV could start directly powering the UK rail network from 2020, according to research from Imperial College and climate charity 10:10. The Renewable Traction Power project would plug solar panels into trackside substations, where trains can directly use the generated electricity. By using direct current rail systems, the electricity generated would not have to be converted to AC, saving around £4.5m ($6m) a year. A first wave of six to 10 solar traction farms could be community-owned and built, supported by 27-year power purchase agreements at a similar price to current contracts, the study showed.

In the U.K., Imperial College and 10:10 have released a report detailing how British rail could be powered by solar PV by 2020, thus saving roughly £4.5 million (around US$6 million) annually. Community-owned models are an attractive option, they say.

With specially designed power electronics, the two explain how PV can be directly connected to electrified railways to supply one tenth of the energy needed to power trains, without connecting to the grid.

Using technology developed by 10:10 earlier this year, the Renewable Traction Power project will plug track-side solar panels into trackside substations, where trains can directly use the generated electricity.

By using direct current rail systems, the electricity generated through the traction power would not have to be converted to AC, thus saving around £4.5 million a year.

Imperial and 10:10 further outline how solar traction power is both technically feasible and commercially attractive under today’s market conditions, with the scheme being potentially operational by 2020.

Demand for traction power from railways is said to be increasing. Railway operators could be supplied with track-connected solar that is both lower cost and much cleaner than grid-supplied electricity. This could result in reduced fares for customers, says the report.

Analyses by Imperial and 10:10 indicate that a first wave of six to 10 solar traction farms could be community-owned and built, with backing from secure, 27 year PPA’s that would supply Network Rail with electricity at a price per kWh equal to the price they currently pay today under their supply contracts.

Solar traction is set to be initially deployed on the London Underground, with 6% of the energy demand covered by solar-power. Following this, 15% of the train networks across Kent, East Sussex and West Sussex could be powered by track-connected solar PV arrays and, in the north of England, 20% of the Merseyrail network in Liverpool.

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However, as the report outlines, there is potential for solar traction power in other countries, like India, which is aggressively deploying solar PV throughout the country and has 25,000 km of rail, which could benefit from it; and Spain, which already has a large solar PV installation base, and 7,000 km of rail, could also expand its PV portfolio by employing solar for its railways.

Switzerland considers solar powered trains

In related solar train news, the Swiss South Eastern Railway AG (SOB) has commissioned a feasibility study from Swiss CMT AG, with the aim of reducing its energy requirements and operating costs.

It found that solar PV is “well-suited” for installation on the roofs train stations, hall roofs, and the soundproofed walls along railway lines.

Initial focus was placed upon PV on the roofs’ of the trains themselves. However, results concluded that the net energy production by the modules remained below the expectations of the engineers, while pollution and space constrictions also had a negative impact. As such, they were not deemed economically feasible.

“Even though it is hardly possible to cover the electricity demand of a whole train with its own solar roof, we wanted to know more about it,” said CMT CEO Marcel Schubinger.