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Comment by nkoren | Hacker News Reader

Let's do this Jeopardy-style.

Answer: "Roads."

Question: "What surface or environment -- by virtue of having no control over shading or solar angle, and by maximising dirt, wear-and-tear, and difficulty of maintenance -- is more or less the worst place on earth to mount photovoltaic panels?"

I mean, I know that roads occupy a stupid amount of surface area, and I understand the desire to do something better with that area. (Tip: just build less of them.) But seriously, as far as solar panels are concerned, they have nothing else going with them.

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During the day, when the sun shines the brightest the roads will have the most amount of traffic, shading the panels from the sun. Doesn't make sense to me.

Why not just spend this money and put solar panels on industrial buildings or state owned buildings?

Most roads don't have much traffic - with a 3 second gap between each car and the cars going at 60KM/hr, the vast majority of the road will be open at any one time. And obviously, when the sun's high up the shadows will be the smallest.

>Why not just spend this money and put solar panels on industrial buildings or state owned buildings?

Proof of concept. Varying solar tech research to find unexpected gains. Maybe it turns out that putting solar panels on roads is actually extremely cost-effective, when you properly adapt the solar panels to road conditions?

There is a lot more area coverage in roads than state-owned buildings. Convert all roads and you can easily power the entire country many times over. If the government is going to foot the bill and make solar power happen immediately, roads have the advantage that they are immediately available land for solar generation. Build solar off-road and you have to choose between a legal battle of evicting civilians from their private property, or destroying government-owned nature reserves. Convert roads and you conveniently dual-purpose existing land area while minimizing environmental impact.

> "There is a lot more area coverage in roads than state-owned buildings"

and there's a lot more area coverage in state-owned buildings without solar than in state-owned buildings with solar, or that will get solar in a reasonable timeframe. It's not like we're running out of rooftops and need to find alternatives.

Even if the government did manage to cover all of their rooftops, there's still plenty of residential rooftop area that can easily be converted with proper incentives. I'm pretty sure we can generate enough solar power to handle all of the needs that solar is suitable for before we come anywhere close to running out of rooftops.

Even if I'm mistaken about how many open roofs there are and how much solar capacity they could handle, there are a lot of other and better options before you get to "put PV cells on the ground underneath semis".

Even better, you can simply install conventional solar panels above existing roads.

There is a law to put solar panels or vegetation (to keep the heat) on roof of any new commercial building, starting in 2016.

isn't the amount of traffic highest at commute times (dawn / dusk) and lowest, excluding night-time, at mid-day when available sunlight is highest?

Traffic is typically during commute hours, which are not peak sunlight hours at most latitudes.

It's also effective to simply put a white coating on the rooftops. (Reflects energy back upwards instead of absorbing it.)

imo it would much smarter to try to extract heat power from roads rather than solar power. I always thought that in warm countries they should install piping under the roads with water that would get heated and brought to boiling thus generating electric power.

Here is idea, instead of building stupidly expensive road that will most likely generate little power - just provide 75% grants to all that want to install solar panels, wind turbines or solar water heaters at their property. Problem solved.

Some roads in The Netherlands have this since 2000. The heat is also used to melt ice and snow in winter.

[citation-needed] for both - not least because of the dramatically reduced power output in winter.

Solar panels are getting cheap. This makes many things that used to be stupid eventually become reasonable.

Don't forget many things where dumb wastes of processing power, until they became reasonable.

The problem is comparative cost. It's much cheaper and more efficient to build regular roads and regular solar panels.

In such configuraiton:

- solar panels won't ever be obstructed by cars

- maintenance will be much cheaper and won't block the traffic

- solar panels won't need to have pressure and wear-resistant cover that is still transparent in the whole spectrum (to not waste parts of it)

- roads will be much cheaper and safer (optimize for grip instead of grip+transparency)

Solar panels are getting less expensive, but they are in no way "cheap" when compared to traditional road construction materials (concrete or asphalt).

Also:

"Glass"

"What is the worst solid dry surface to try to drive over?"

But can the panels survive a snow plow? If not, you're limiting it to perhaps(?) half of France. Yet everyone in the entire country pays for it with the gasoline tax.

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