There’s been a lot of excitement recently on social media about this solar roadways idea developed by a couple of engineers (they’re actually a couple, who are both engineers). Their vision is infectious (though–why hexagons? Wouldn’t that waste a lot of edges?). Replacing roadways and parking lots with durable solar panels will turn all our empty asphalt into power plants. What’s more, we can embed sensors and LEDs into the panels to make them smart roads. It would be a huge infrastructure project that would create thousands upon thousands of jobs and pay for itself in free, clean energy.
Now, as an arch-leftist tree-hugger, I’m always glad to see people get excited over renewable energy…
You sense a “but” coming here, don’t you?
It turns out that roadways should be the last place we put solar panels, not the next.
You see, current technology only returns a tiny sliver of the sun’s energy back to us in the form of electricity, so it’s best to put solar panels in areas where they get maximum solar exposure. For us here in the northern hemisphere, that means up on roofs, pointed south.
On a road, much of the solar energy would be blocked by grime, debris, oil, shade trees, or just plain ole traffic. Though coating huge surface areas seems tempting, the actual gain might not justify the cost and the trouble of maintaining them. In short, given current technology, the roads might not pay for themselves as promised.
Smart roadways are tempting, and perhaps we could use an approach like this in some settings–the basketball courts and parks the video suggests might be interesting, as human feet won’t put as much stress on the panels as dump trucks and they won’t cast as much of a shadow, either.
Down the road, we might be able to make solar roadways worth the trouble. Every other week, university labs are cooking up new and exciting prototypes for new solar technology–from paint you can put anywhere to transparent cells that can be embedded in windows. The breakthrough to make power-plant bike paths practical could be one published paper away. So, maybe.
The bottom line, though, is that if we’re looking for places to invest in solar energy with today’s technology, then there are a lot of empty roofs waiting right now. Even smarter would be car shades with solar panels in parking lots. Turn those ungodly Walmart blacktop deserts into something useful for society.