Daily, countless rail passengers departing Aldershot station on southwest-bound services travel past a modest solar installation positioned alongside the railway tracks. Most travelers remain unaware of this facility. Yet their train receives electrical power from these very panels.

"On a sunny afternoon, if you are catching a train through Aldershot, a little bit of the energy for that train will come from those solar panels," says Leo Murray, co-founder and chief executive of Riding Sunbeams, a start-up aiming to use renewable energy resources for rail electrification projects.

Riding Sunbeams constructed the Aldershot installation in 2019. The facility operates at a modest 40 kilowatts capacity, matching approximately ten residential rooftop solar systems found across typical British households. However, it showcases the potential for renewable sources to supply power directly to railway networks.

Furthermore, Mr Murray notes this represents Britain's sole solar facility providing electricity straight to rail infrastructure for train operations. "If you are a railway, this is the cheapest electricity you can buy," he adds.

Across Britain and globally, numerous trains continue operating on diesel fuel. Railway companies seeking electrification have historically chosen between two approaches: electrified third rails or overhead power cables that trains access through roof-mounted pantographs. Both installation methods present significant costs and technical hurdles.

However, engineers are developing innovative implementation approaches while entirely novel alternatives emerge that could accelerate electrification initiatives.

Local electrical grid constraints frequently obstruct electrification efforts, making it difficult to secure substantial power connections for train operations. "That problem has only become much, much worse," says Mr Murray.

This challenge explains his enthusiasm for solar technology in facilitating railway electrification endeavors.

Following the Aldershot installation, Mr Murray anticipated Riding Sunbeams would proceed with a comprehensive commercial demonstration project. However, financing obstacles prevented this progression.

Currently, Network Rail, Britain's railway infrastructure owner and operator, is soliciting suppliers for trackside renewable energy initiatives.

"This is the big one," says Mr Murray, explaining that his business is planning to bid for a contract.

Fresh projects introduce additional complications though. The Aldershot location featured pre-existing electrification, requiring only solar panel integration into established infrastructure.

Converting diesel services to overhead power systems while incorporating solar presents greater difficulty. Solar installations generate direct current electricity while overhead systems operate on alternating current.

Development work continues in England on innovative converter technology to address this technical challenge.

Meanwhile, Colton Junction linking Leeds and York, Britain's highest-speed railway junction where trains traverse at 125mph, recently received electrification using software created at the University of Huddersfield.

This software generates three-dimensional overhead line system models, enabling engineers to plan construction with precise detail while reducing expenses by eliminating traditional testing and assessment requirements.

"Everything was specified in the software in terms of measurements," says João Pombo, associate director of the university's Institute of Railway Research. "All the trains are running at maximum speed at that junction since August."

Alternative electrification concepts are gaining attention. Polish startup Nevomo has created an electromagnetic propulsion technology that retrofits onto existing tracks by installing thick aluminum cables within enclosures running between rails. This configuration produces magnetic fields powerful enough to move freight cars equipped with magnets.

"We eliminate locomotives completely," says Ben Paczek, founder and chief executive. "Each wagon becomes independent. They can also operate in groups."

According to Mr Paczek, the technology's primary advantage enables rapid freight car stopping, potentially allowing numerous independently operating wagons to travel safely in close proximity along single track sections, thereby increasing freight transport density within specific areas.

Nevomo plans to deploy operational systems at a Bremen, Germany steel facility and an Indian port facility next year.

These initial implementations will cover relatively short distances under 1km each. Mr Paczek envisions larger future installations. "In a quite conservative environment like rail, we need to demonstrate it properly first."

Automated operation of electromagnetically-driven wagons remains possible, though human operators will initially control them remotely.

In America, Parallel Systems pursues individual freight wagon electrification for independent network movement using battery technology. The company's wagons would achieve 800km operational range, according to co-founder and chief executive Matt Soule.

He characterizes this approach as resembling distribution center packet movement, describing it as "atomised freight" that contrasts sharply with conventional locomotive-hauled freight trains exceeding 2km in length. "We're focused on doing the shorter stuff that they're not doing," says Mr Soule.

Rather than replacing freight locomotives, he seeks to establish rail-based delivery services competitive with trucking. "If we simply grab 10% of the trucking market, we've doubled the rail industry," he says.

Stuart Hillmansen at the University of Birmingham, who previously collaborated with Riding Sunbeams, suggests coordinating individual freight train movement across existing rail networks could prove "quite challenging – certainly on [British] railways".

Nevertheless, he acknowledges emerging technologies facilitate electrification efforts, with electrified trains becoming the preferred choice for new railway projects.

"All of these technologies are physically feasible and can work, the thing is managing the business case," he says.