This week, on Facebook, I joked that I'm going to launch an Indiegogo campaign for growing all of Canada’s vegetables in gardens atop porkpie hats. I was reacting to the depressing news that the Solar Roadways project got more than $1.8 million in donations from thousands of individuals. What were they supporting? The unicorns-and-Skittles dream of Julie and Scott Brusaw to replace the highways, parking lots and sidestreets of America with smart, hexagonal solar glass tiles. The couple believe their solar roadways can decrease our reliance on fossil fuels, power the U.S. with the clean energy of the sun, can melt ice and snow, embed road signs and make U.S. roads safer.
I think the Idaho couple are sincere and well-meaning, but their plan makes as much sense, well, as growing all our vegetables on the tops of our heads.
Let’s break it down a bit. Solar panels work by converting solar energy into electricity. They only do that, of course, when the sun is out. And, even the best panels convert about 15 per cent of solar to electrical energy. And, those efficient panels need to be away from shadows, in areas with lots of sun and be clean and transparent to be at their best. You know where a really, really bad place for a solar cell is? Under a car on a dirty highway. Where’s a dumb place to put a solar panel during the day? On a surface of a parking lot covered with opaque cars. And where’s an odd place to put solar panels at night, when there are no cars to block the sun that has gone down? A parking lot.
That sound you hear is the loud thump of a million civil engineers all hitting their foreheads against their desks at once.
The couple claims heating elements in the glass cells can melt ice and snow on their solar roadways so snowploughs will be a thing of the past. They appear to have no real idea how much energy it takes to melt snow (hint, a metric buttload). And, snow and ice are real issues in northern climates (where solar energy is low) and in the winter (when the days are short). Using solar cells to melt the ice on them is about as practical as using a drinking straw and an asthmatic six-year-old to drain an Olympic-sized swimming pool.
The solar panels are hexagonal with spacing between them. Do you know why roads aren’t already paved with tiles? Because the uneven weight on them as cars and trucks pass over works them loose and breaks down the subsurface. It's like when you were a kid and you wiggled a loose tooth free with your tongue, except that your tongue has eighteen wheels and is carrying ingots.
A promotional video for the project shows the couple loading crushed, coloured glass into a wheelbarrow, as if they are going to make their clear, tempered glass panels from the multi-hued beads. While I do think the couple is well-intentioned, that scene made me mad and caused me to wonder if they aren’t scam artists, after all.
It is ridiculous to think that the chemical and thermal processes needed to turn coloured junk glass into high strength, clear panels would in any way be economically feasible. And let’s not even start about the end-to-end carbon footprint of “green” panels made from recycled glass. Because, remember, the energy to melt the glass at high temperatures has to come from somewhere.
But, the final nail in this wacky notion’s coffin is that the video fails to mention anything about energy storage and transport. Energy from solar cells is typically low voltage direct current. That’s notoriously hard to transmit over long distances. That’s why Edison’s electric schemes for the U.S., which used direct current, were defeated by the alternating current systems proposed by Westinghouse.
So, you’d need to convert the D.C. to A.C., store it at night (requiring millions of batteries) and then rig up an electrical transport system that runs along all the highways. The cost of all that is astronomical. Plus, all the workers who now are employed laying hot asphalt would be replaced by electricians, who are, you know, really inexpensive by the hour.
Worst of all, there are more practical alternatives literally so close. Solar panels on the roofs of car parks, or tilted at practical angles in grids alongside the highways themselves, for example. Which is exactly what Oregon has done.
So, given the blissful naivety of the doomed and beknighted scheme, why did thousands of us share the videos on reddit, facebook and other social networks? And why, for the love of sweet baby Jesus on a Triscuit, did they give it money? I think for two reasons.
First, I don’t think most folks who shared the video know enough of the practical science to deconstruct the claims. But, more importantly, sharing it wasn’t showing support for the practical idea, it was about supporting the belief that one simple, out-there idea could solve all manner of social ills. A bullet as silver as a herbal cancer cure or miracle diet.
It wasn’t about the practical. It was about the magical. In fact, many of the posts I saw about the scheme said, “Share this if you believe in it.”
But belief has nothing to do with success when success runs headlong into material science, thermodynamics and civil engineering. We may all believe that clapping our hands loud enough will make the tarsands disappear, or that a drum circle will collapse the Harper regime. But magical thinking isn’t helpful. And magical ideas aren’t worth spreading, funding or defending. We should all keep our powder dry for the ideas that can really make a difference.
And on that note, porkpie hat vegetable gardens, there’s an idea you should all get behind.