So laying a bike path that generates electricity through solar cells embedded in its surface should be a brilliant win-win. I’ve now pedalled across the 70 metres of experimental ‘solar road’, opened last week to some fanfare at Krommenie, a Dutch village north west of Amsterdam. I’ve also done some reading.
Sorry, but it strikes me as a very silly project.
Facebook has excitedly been spreading the word. Solar roads could be the answer to all the planet’s energy problems.
The idea of the Krommenie experiment is to measure the amount of energy that can be harvested from a bike path which otherwise just lies around all day reflecting sunlight. Why not collect that energy, and put it to good use?
I’m neither a scientist nor an engineer, so I bow to the expertise of Bard van de Weijer, science editor of the respected Dutch newspaper De Volkskrant. He has serious objections to the plan. Unfortunately he’s written them in Dutch, so I have to paraphrase them for my readers…
First, if you ride a bike across a normal solar panel, it will probably bust. To make it bikeproof, it needs a tough layer of glass over it. There goes a few percent of its effectiveness.
Normal glass is a bit slippery for bikes; like ice in fact. So the surface needs to be roughened. You guessed it, roughened glass collects even less sunlight.
So here’s a radical idea – put the solar panels on a roof, particularly a slanting one angled towards the sun. No need for a protective coating, so long as nobody gets drunk and proposes a high level bike ride challenge.
Proponents of the solar road scheme argue there simply aren’t enough roofs to support the number of panels needed to replace Nederland’s fossil fuel energy, while there’s ample solar capacity on the bike paths and roads. Mr van de Weijer argues that this is like putting the kitchen cutlery up in the attic because there’s more room up there.
I think he’s right. I noticed a few rooftop solar panels in Krommenie, but an awful lot of vacant roof space pointing directly at the sun. When Kommenie runs out of roof space, that could be the time to start on the solar roads.
Then there’s the cost – reportedly 3 million euros for the 70-100 metre section of Solar Road. You’re kidding? For that kind of money, I’m sure I could find a few cyclists prepared to hitch their bikes to generators and spend a few hours each day getting worthwhile exercise while contributing to Krommenie’s energy needs.
And I have another question. Why do we need to do the experiment on a real bike path? Why wouldn’t a square metre of ‘solar road’ out the back of the lab be enough to test the effectiveness of its energy collecting? Multiply the result by a few hundred and you’d have the capacity of the Krommenie cycle way. And don’t engineers already know enough about the durability of these materials to be able to estimate the product’s lifespan and maintenance costs?
If the system is demonstrably sustainable and cost effective, why would anyone just lay 70 metres? Why not 70,000 kilometres? If it really works, why not hand it over to a commercial company that can roll out a whole solar bike path network? There’d be a massive profit in it and good luck to whoever takes it on.
The whole thing smacks of an expensive publicity stunt. A local authority wants media coverage that shows it doing something good for the environment. Well intentioned, of course, but they know subsidising local residents to put solar panels on their roofs wouldn’t get people like me blogging about it.
It will be great if the solar bike path turns out to be the answer to sustainable, non greenhouse gas-producing energy, though I suspect if a scheme sounds too good to be true, it’s not true.
The project has already had one valuable side effect; it gave me an objective for another day’s riding. The scenic route from Amsterdam to Krommenie is about 37 kilometres. Getting there was more than half the fun.
If you’d like to comment, for or against the solar roads idea, I’d be very pleased to hear from you.