According to the UK's Wired magazine, if you live in south London, the trains you ride could soon be powered by solar energy. A recent study by Imperial College London and the Green Energy charity found that solar power could meet 10% of the energy needs for Britain's DC-powered rail trains.

The research report suggests that solar energy can bypass the national grid and eliminate additional energy losses, making it cheaper for trains to run on solar power compared to conventional electricity. According to "Riding Sunbeams," 15% of the train networks in Kent, East Sussex, and West Sussex could be powered by solar photovoltaic cells integrated directly into the tracks.
　　In addition, 6% of London's subway energy needs could also be met using solar power. This amount of energy is equivalent to half of the electricity consumed by the Piccadilly line alone. Moreover, according to reports, 20% of the rail network in Liverpool, located in northern England, will soon be powered by solar energy, while rail systems closer to the equator could eventually rely entirely on solar-powered battery systems for their energy supply.
　　"A researcher at Imperial College and the project supervisor, Nathaniel Bottrell, said: 'This study aims to determine whether the electricity generated by a standard solar power plant can effectively align with the energy consumption patterns of trains. The good news is that, technically speaking, this project is feasible—and it also holds significant economic appeal.'"
　　The railway system operates on direct current, and the electricity generated by solar energy is also DC—eliminating the need for an AC-to-DC conversion system, which translates to annual savings of approximately £4.5 million. Leo Murray, the project leader, remarked: "It’s truly a remarkable coincidence that solar power happens to produce DC as well. Railways require 750 volts of direct current, and the voltage output from the solar panels falls precisely within the 600-to-800-volt range. This perfectly aligned match between the type of current and the voltage levels produced by the solar system—and their exact compatibility with the railway’s needs—is nothing short of delightful."
　　The DC railway network was one of the earliest types of railways built in Britain, but it was later replaced by the safer AC network. In AC railway systems, cables are positioned above the trains rather than near the tracks, significantly enhancing their safety. However, because DC railways are compatible with solar energy, Imperial College—and this project—will focus exclusively on research related to DC railway systems.
　　Bottrell said, "The declining costs of energy storage are making this proposal more economically viable." Advances in storage technology mean that solar systems won’t waste energy. Bottrell added, "There may be times when solar systems generate electricity but no trains are running on the tracks—periods of idle capacity. However, battery storage can perfectly address this issue, ensuring the railway system has enough power both at night and during peak morning hours."
　　Bottrell stated: "All solar equipment must be compatible with the railway system, and it’s clear that this technology needs to undergo testing to ensure it won’t interfere with critical systems like signaling." Researchers predict in their report that these tests could be approved and successfully implemented within two to three years. Lead official Murray added: "While installing energy storage systems may not pose a major commercial challenge, integrating them into railway lines could prove quite costly—something the railway authority will need to carefully consider."
　　Phillip Thies, a senior lecturer in the Department of Renewable Energy at Exeter University, believes that commercial negotiations could prove to be the biggest hurdle for this idea. He explains: "The proposed approach involves installing them close to existing power stations. Given the availability of land and the permitting process for large-scale solar panel installations, this project could have significant practical implications." Nevertheless, he also acknowledges that the initiative lays a solid foundation for exploring potential investments.
　　However, in terms of scale, the UK may already be lagging behind many other countries. India, meanwhile, boasts the most ambitious goals, aiming to build a solar energy network and planning to generate 100 gigawatts of power through solar panels by 2022. According to Tim Green, head of Imperial College’s Future Energy Lab, "We’ve also seen similar plans emerging in the Netherlands—specifically, their railway network is set to run entirely on 100% renewable energy." Although the UK currently remains at a smaller scale, such initiatives could eventually gain more attention, driven by the growing economic advantages of solar energy.