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Solar Roadways Project Beats $1M Goal, Should Enter Production
Lucas123 (935744) writes "It appears an Idaho-based company that created prototype panels for constructing roads that (among other features) gather solar power, will be going into production after it exceeded its crowdfunding goal of $1M. ... Solar Roadways' Indiegogo project has already exceeded $1.6 million. The hexagonal-shaped solar panels consist of four layers, including photovoltaic cells, LED lights, an electronic support structure (circuit board) and a base layer made of recyclable materials. The panels plug together to form circuits that can then use LED lights to create any number of traffic patterns, as well as issue lighted warnings for drivers. The panels also have the ability to melt snow and ice. Along with the crowdfunding money, Solar Roadways has received federal grant money for development."
> Isn't it impossible for solar cells to melt significant snow?
Yes. Obviously if there is enough energy in the sunlight to melt the snow, the snow would melt already.
Heating snow to clear it is multiply-times less efficient than scraping it off with a snowplow.
This whole idea is the dumbest thing I've seen in years, designed by someone who knows nothing about solar power or road engineering. Ask anyone on the planet who's ever had a re-lay a cobblestone road surface how well they think this will work.
You missed the whole point of durability that I mentioned.
In Thailand, many of the roads in the southern areas use glass balls as lane markers. They don't get driven over unless a wheel is in on the lane marker, hence, only a small fraction of the actual traffic. Nonetheless, it is plainly obvious that they just don't last. They are chipped and damaged to the point that they don't fulfill their function.
Roads are possibly the most abused surface mankind makes. No type of glass that we have access to could ever stand up to long term road wear. It's just not possible with today's tech. I really think that this is a grant scam, which is unfortunate, because the politicians being scammed will be less favourable to green projects the next time a real idea comes around.
I hate printers.
Seriously, cobblestone?
I'm a transportation engineer (I'm posting this anonymously so the details of my employment are not associated to my account) though with very little experience designing pavements. What my experience tells me though is that regardless of the panel itself it needs some sort of frame to hold it down.
Vehicles generate thousands of pounds of force parallel to the pavement face when they brake. This is what causes rippling in pavement at intersections when the asphalt is too soft or weak. So they've got the friction to stop the car what transfers that force to the ground (and prevents the ground from shifting)? Naturally you are going to need some sort of frame with very positive connection to the ground. That sounds unbelievably expensive. Current roadway costs are near $2 million dollars per lane mile (a 12 wide width of pavement 1 mile long). The materials that make up the roadway are generally pretty cheap (various engineered sands and gravels) and are applied to the roadway using large heavy equipment with very little human labor. You've now replaced that with presumably the same base system (you still have the same loads) a metal frame to hold the panel in place and the panel (these systems would replace the hard surface ie the asphalt or concrete). Even a minimal frame material wise is going to massively expensive. Steel is very very expensive in rough bar form (in comparison to things like concrete and asphalt), let alone in machined frames that require manual hand labor to install. What happens when a frame is bent? How's it anchored? Even massively damaged pavements are usually traversable, a missing or damaged panel sounds like a 2' circumference 1' deep pothole that will rip a tire off a vehicle at speed.
The next question is durability. They say they've tested them with truck loads, have they done the standard AASHTO pavement test that involves driving a semi around (in a 1/4 mile loop track) on them for 5 years straight to demonstrate long term durability? What about studded snow tires? What about an accident where a car flips at 70 mph and imparts forces that literally pulverize concrete to powder? What if the car then burns (a typical car fire approaches 3000 degrees) What about an accident where hazardous or corrosive products are spilled? What happens when a car being chased by the cops has it's tires shredded but then keeps driving on rims for 20 miles until the rims literally weld themselves to the rotor (the typical result on standard pavement is about a half inch groove from every rim for the length the car ran without rubber)? What about road debris coming off cars and hitting other cars (I've seen sections of concrete a foot thick destroyed by heavy objects falling off semis)?
How long are the panels good for? We design asphalt roads for 20 years and concrete for 40-50 years. And though the asphalt requires perodic treatments as part of it's life cycle unless a mistake was made they generally last that long. Most of the interstates lasted far longer than the 40 years they were designed for, in my state we've still got original interstate in locations that is approaching 60 years old.
We use the materials we do in roads because they are cheap, easy to put down (ie not labor intensive) and easy to fix (a temporary fix can involve dumping and spreading a load of gravel with common construction equipment). This system just screams money, and labor and lack of durability. Maybe I'll be wrong, I suspect I won't be. The ESALs (equivalent single axle loads) that a pavement takes over a life time can be astonishing (trillions of pounds of force over a 20-40 year lifetime). The panel and frame that support this are going to be flexed billions of times a year, fatigue fractures are a very real concern in metals.
Anyway, as I say I might end up wrong, i suspect I won't. I'm astonished people donated a million bucks for this and I believe once they do the real AASHTO testing that will be required before this can be used on roads they will demonstrate