In 10 years time, trains could be solar powered - Alice Bell, Guardian correspondant

Last week, my 10:10 colleague Leo Murray co-authored a new report on solar-powered trains with Nathaniel Bottrell, an electrical engineer at Imperial College.

It’s exciting stuff. We think solar could power 20% of the Merseyrail network in Liverpool, as well as 15% of commuter routes in Kent, Sussex and Wessex. There’s scope for solar trams in Edinburgh, Glasgow, Nottingham, London and Manchester too, and there’s no reason it should just be a British thing either. We’re especially excited about possibilities in San Francisco, Mexico City, India and Spain, but trains and trams all over the world could be running on sun in a few years time.

It’s also a genuine world first. There are a few solar stations – Blackfriars Bridge being by far the coolest – and some trains in India even have solar panels on their roofs, but that’s just to power equipment like lights and fans. No one’s moving the trains themselves with solar. Yet.

What’s especially interesting is how our new innovation came about – in particular the role community energy groups have played in its development (often despite policy support, not because of it, or in response to policy constraints). Looking ahead, there are also important questions to be asked about what role these community groups might play in its deployment.

The idea came from a community solar group in Balcombe, West Sussex, formed in response to the first anti-fracking protests in the UK, in the summer of 2013. After the drillers, the activists, the press and various other hangers-on had left, the villagers were left with a question our current energy system lets most of us ignore: how should we power ourselves?

They decided they wanted local, community-owned energy, and also that they wanted to go solar. Looking into places to site a solar farm, they initially found the local grid didn’t have the capacity to take more solar. Searching for a way to solve that problem, they looked at the local railway and asked an engineering professor who happened to live locally, “could we plug it there, instead?” His answer was yes, they could, but the technical challenges to get there were a bit too much for a small-scale community group to grapple with. So they found another nearby solar site that could plug into the grid.

But when solar cuts hit the UK in 2015, we dug out the idea. What had been a possible local solution to Balcombe’s grid capacity issues a while back could build into a larger opportunity for renewable energy everywhere. Community energy shouldn’t have had to innovate at that point – renewable energy tech’s pretty great as it is – but with the solar cuts so deep, and onshore wind effectively banned in England, the solar trains idea gave us options. So 10:10 teamed up Energy Futures Lab at Imperial College London, umbrella group Community Energy South, and electrical engineering specialists Turbo Power Systems to find out more under Innovate UK’s Energy Game Changers competition.

Looking ahead, it will be a few years yet before we’re able to deploy the tech necessary to plug solar into trains. It needs building, and it needs testing, but I’d be shocked if it doesn’t happen. What’s less clear is whether community groups will be involved as solar railways roll out. As they’ve been part of this from the get-go, they’re super-keen. But it’s all too easy for the public to be shunted to the sidelines when the big budgets and complexity of infrastructure projects get going.

It’s common for public involvement to be seen as an inefficiency – in science, politics, finance, technology and more – a “nice to have” that takes too much time and effort when we’re in the serious business of things like climate change, economics and keeping the trains running on time.

But the opposite is true, especially when it comes to climate action. It’s the public who are driving change, often despite the actions of policy-makers.

Community energy offers a particularly powerful way to give members of the public a role in decarbonisation. Moreover, by tapping into their energy, enthusiasm and ability to bring other members of the public with them, we’ll get it done faster, as well as fairer. If it wasn’t for community energy groups coming up with this idea, pushing it forward and scoping out the places it could be utilised, solar trains would still be far more than a few years away.

Alice Bell was a founder member of the Political Science blog. Previously an academic in science communication and policy studies, she is now co-director at climate change charity, 10:10.