How much extra energy would it take to transport these solar cells while they are collecting the energy? According to the rough calc above it would take around a month to produce the equivalent of 1 gallon of gas. Meanwhile you have been dragging several pounds (?) of extra material in your car for a month, not to mention any aerodynamic effects.
I’ve always wondered why the newest sailboats don’t have solar panels built into their decks…it seems that solar energy captured at sea could be used extremely effectively especially because power outputs are substantially smaller than on land (aside from the primary engine).
My Prius has a solar panel on the roof. It operates the A/C on hot days. That’s all it does. I don’t think it generates enough power that they would even bother hooking it up to the batteries to boost the charge.
What kind of solar panels can withstand salt water and wind and being stomped by sailors?
Why can’t solar panels be embedded behind plexiglass? Or they can be added to non-deck areas, see here: http://c470.jerodisys.com/470pix/47004.htm
My guess is this will be standard on many boats at some point
[bolding added]
I don’t understand what the bolded statement means, but there are several reasons why sailboats are not constructed with solar panels constructed in the deck. For one, decks are working surfaces that the crew is constantly walking over during maneuvering or trimming of the sails, which would require having a transparent polycarbonate cover that will eventually get scratched up and opaque through polymer breakdown. Second, fiberglass decks experience a lot of flexure which would require the mounting of the panels to allow for shear. Third, decks are frequently covered with spray which significantly detracts from theoretical efficiency. Also, when trimmed for a beam reach or higher, much of the deck is in shadow of the sails. Depending on the azimuth of the Sun and the orientation of the boat, the deck may or may not be at an angle of incidence to even effectively generate power. At any given deck angle the deck can only obtain effective angle of incidence for about thirty percent of the solar day. All of this adds up to low efficiencies for deck-mounted solar panels which also add both purchase and maintenance cost to the craft.
Now, many cruising yachts–those intended for extended blue water sailing–are outfitted with a solar panel that is generally suspended off and above the transom, which is generally less shaded, and some even have systems that will adjust the angle of the mount to maximize solar incidence (though, as with any complex or sensitive electromechanical device in a marine environment, it will corrode and eventually fail, usually at the most inconvenient time). These are generally used for recharging batteries or powering auxiliary devices without having to use the generator or alternator, and provide only a modest amount of energy.
As for the question of the o.p., the issues with it have been adequately addressed. I worked on the Solar Challenge/Sunrayce team at my engineering school for a couple of semesters. The vehicle was essentially a recumbent tricycle frame with a large fairing covered with solar cells. The entire thing could be picked up by two or three students. As a demonstration of engineering ingenuity it was clever, but it was not a remotely practical vehicle. SAAB and GM were at one time working on projects for roof-mounted solar panels to power a cooling fan while the vehicle was parked (similar to the concept mentioned above) but as it has clearly not advanced to being a production option I can only conclude that it was determined to be not appealing or fiscally worthwhile.
In general, PV solar power is only practical in large installations, for remote facilities for which connection to a power grid is not practical and energy demands are limited, or as a supplement to existing power supplies. Even then, the ROI is pretty marginal, especially compared to energy efficiency enhancements such as thermal mass storage, high efficiency appliances, and natural convection for cooling. The footprint required to generate enough solar power to be useful
Stranger
A marginally more practical idea would be to “pave” the roads with solar panels.
Seems kind of a thin margin, though. Intuitively, you’d think that costly, high-tech surfaces would be something you’d try to avoid driving on, and I’d hate to have to deal with road closures for maintenance on the panels.
That said, plenty of human progress has been counter to intuition. 
Like this:
[noparse]X[sup]2[/sup] or Y[sub]3[/sub][/noparse] makes it look like this: X[sup]2[/sup] or Y[sub]3[/sub]
Just think SUPerscript or SUBscript.
Solar panels are being developed that are quite flexible and can be shaped to irregular surfaces. Now if only they developed material that was REALLY flexible and could be made into sails…
[quote=“Stranger_On_A_Train, post:26, topic:583924”]
[bolding added]
I don’t understand what the bolded statement means, but there are several reasons why sailboats are not constructed with solar panels constructed in the deck.
I meant that shipboard appliances require less power then their counterparts on land (stove, lights, fridge, etc.)
Quoth kanicbird:
The Martian rovers are also a lot slower than most people realize. On flat, level ground, with optimum conditions, they can do about 2 inches per second.
Not unlike the freeway at rush hour, so I guess that would work.
What type of A/C does that solar panel actually power? I doubt you are talking about a car style of compressor, or even a peltler solid state cooling device, is the Prius A/C a real A/C or just a fan? And if it’s a real A/C how do they get it to work on that small solar panel?
Here’s a solar panel for RV’s that claims to deliver five amps at 12 volts.
And here’s a battery page that (if I’m reading it right) seems to indicate that a 1/4 hp trolling motor capable of a steady speed of 3 knots will pull 10 amps at 12 volts.
It looks like it’s going to be a slow trip.
Thank you.
No, it’s solar film. Their drag effect is negligible. And it would be 1/5 month for a gallon of gas. I’m going for 1 mile per hour in the sun as a minimum of practicality. I bet you could squeeze at least 3 m[sup]2[/sup] onto a Cutlass Supreme…
The idea isn’t to have it fuel your trip, but rather be the second coming of regenerative braking or something.
The panel would not have to power the car.
A storage bettery might be topped off when the car was not in use, or the range per charge extended.
This link claims the Prius solar roof can provide 20 miles worth of power:
How much power are they talking about? Is this a reliable claim? And if every vehicle in the US had one, how many bbls of oil would be displaced?
Not sure. I thought it was air conditioning, it certainly feels cool and makes a bit more of a noise than I thought a fan would make. Google, however, tells me it’s just “ventilation.”
You have already been given an answer to this question. This device is no different than the hypothetical one you proposed originally, except perhaps slightly larger.
This particular product is an aftermarket device that provides 250 watts in full sun. It only powers the car for “20 miles” if you let it charge for the appropriate amount of time (hours upon hours, or more in anything less than full sun).
My post above indicates that such a device, if equipped on all cars, would produce energy equivalent to 1/60th of US gasoline consumption (on average).
There is no magic solution to this issue. The sun is just not bright enough to make solar power of the type you’re considering economical or worthwhile.