http://ucsdnews.ucsd.edu/pressrelease/c ... n_diego_fi
60% is completely unrealistic. I was thinking something more like 30%, optimistically speaking. The dirt is a huge problem. Even on tilting panels raised above ground level, dust accumulation results in losses between 1% and 50%.
7,4% difference between cleaned and uncleaned solar panels in California. Not that much. As for roads? Who knows - *we need data*, which is why projects like this matter. Roads are dust generators, but they also have agitation of surface water when it rains by tires, and cars kicking up collected dust when it doesn't. Some quick googling for dusty roads (in dusty areas, where *everything* is getting coated by dust) shows that tires appear to actually *clean* roads of dust. Eg:
Compare where the tires have been traveling to where they haven't.
So again, to reiterate: we need data. Real-world data, not speculation.
Cosine losses can already amount to about 20% losses compared to fixed tilt at temperate latitudes, or more than 30% compared to tracking tilt
Or 0% difference relative to frameless commercial rooftop solar, which nobody in these discussions ever seems to have any opposition to. For utility scale farms, it's about half fixed tilt and half tracking. So call it 7,4% dust and 25% cosine. That's 70%. I said 60%. Where's the problem? How much loss exactly are you expecting in the resin coating?
And this ignores the fact that the panels are already substantially more expensive and less efficient than existing technology
they're substantially more expensive. In the long run, I seriously doubt that. Yes, they need to be able to take varying compressive loads, and they have a wear surface. But they also don't need mounts, foundations, and face no meaningful wind loads (adhesive bound to the substrate). Yeah, I think they'll be more expensive in the end. But I suspect that in the end, the cost over non-road-panels will be about the same as the money saved by not having to build the road traction surface that you'd have otherwise had to build. Who knows? *We need data*.
"Less efficient": it sounds like you're trying to double-count our aforementioned discussion of dust, angles, etc.
But the new surface is much more expensive, not just to build, but to repair. You have to lay tiles by hand.
I'm not sure you've been reading what I've actually been writing. I've been talking about the scenario where - as the technology matures - they transition from hand-laid pieces to continous reel deployment from a specialized solar paving vehicle. Your mention of tiles makes me think you're still thinking of the stupid "Solar Freaking Roadways!" people.
By comparison, a traditional road surface might as well be free.
Nothing is free.
The repair costs are also likely to be very hig. Even if the materials are as durable as they say, they won't last as long as asphalt
Says who? No, seriously. Can you even tell me what the layers of their panels are made out of? What the resin that binds the glass bead aggregate? Etc? If you don't even know the structure of what you're talking about, how do you feel like you can comment *at all* about how fast it will wear? And Asphalt isn't exactly a long-wearing substance. It degrades in the sun and devolatilizes and oxidizes when exposed to air. This makes it progressively more brittle. Maintenance is usually needed after ~15 years or so.
two-for-one ... Do you have any numbers on that?
Yes, see my last post (which I was writing while you write yours)
For solar roads, you still have to plan the roads, get permits, and pay for the labor, just like building a farm
And when you're done, you have both a road *and* a farm, hence the comments about two-for-one. The road is literally the foundation-slash-frame for your panels, and the panels are literally the traction layer of the road.
What if the road doesn't provide good traction in wet or cold conditions?
You mean, if Colas developed a bad traction coating? Then they need to make a better one or give up, obviously. You know how we find out how good the traction is? By testing, rather than just throwing our hands up in the air and saying "anything new will fail."
And IMHO, do you know what you call "small grains bound with a polymer resin onto a surface" in real life? We call it sandpaper. I actually expect traction to be quite good.
What if it wears more quickly?
What if broken tiles pop tires
Okay, you are very clearly not reading
. We are not talking about the "Solar Freaking Roadways!" people and their overcomplicated glass tiles.
. We're talking about the potential evolution of something like what Colas is testing in France. Look at it:
What if it has a lower coefficient of friction?
What if we started repeating "what ifs" that we had already raised to try to make it sound like there were more potential things that could go wrong than we could think up?
What if it expands when heated?
What, you mean like asphalt?
What if it reflects light into drivers' eyes?
Which is why you do trials like what Colas is doing in France to see how it works in the real world
The problem with building on top of roads is that transportation is extremely expensive, extremely important, and extremely dangerous.
. Do you understand what I'm saying? I'm saying collecting data on a meaningful concept that may or may not work out - but could
- is a good thing
Oh, and then there is the issue of actually transmitting the power. How does this project safely transmit so much power from the road to the grid without additional losses and infrastructure?
Surely you know that power lines are a thing. Whether in underground conduits or overhead wires. Power is transmitted within the roads to branch points (such as rows interlinked in parallel, columns in series, up to the branch DC voltage), and from the branch DC lines to inverters for AC wherever desired. Nothing special about that. For Colas's system, it looks like there's a primary conductor in the midline of the lane. It appears to reach what may be an inverter next to the power line via an underground conduit - although that's speculation.