I came up with a silly idea, but the more i think about it the less silly it seem, other than "really expensive"


For the sake of the conversation, lets assume The product we need are as expensive as normal floor tiles so price is no issues.

The idea would have been to have photo-voltaic cells floor tiles. Since we usually design thing to have the light up shining down (probably because we try to copy what we know work in the "nature") The angle should be optimal for photocell.


So what am asking to this community (that tend to be slightly more scientific knowledgeable than me is, would we be able to regain enough energy to be noticeable. please do not considering the fack that sunlight will shine on those tiles once in a while.


Also what would be required to make those "affordable" but still durable?

you may also post other silly idea like that. I know it more science that fiction, but science can be fun!!! *point finger to the sky*

you COULD go one better, and use electrolysis tiles, which split water into hydrogen and oxygen, to be stored in tanks out back for all your balloon and 'high on life' needs.... also hydrogen fuel cell cars and home-made oxyacetylene explosive balloons <_<

But TBH the problem with photovoltaic is they don't work as well as you would like unless more than 50% of the connected panels are lit.
There is some voltage and current leaking in those panels without enough sunlight, which damages the panels gradually.

It's not MUCH, but I understand it's a interesting reason PV panels die of 'old age' in the real environment faster than in the lab (where normally the whole panel is fully lit while under testing)
The fact that silicon is damaged by intense sunlight is another :p

But you also have a second point to consider with your tile suggestion: It's pretty and all, but have you considered how much the electrician will charge to wire the floor?
Have you considered how to waterproof the tiles so you can mop when it's dirty?
Have you worked out how to prevent water getting into the wiring system?

Ultimately, this is why design engineers like playing with pre-made tools with well known pre-existing issues, it's easier than trying to develop new solutions to new problems :p
It also happens to be why Engineers who develop new technologies either get paid REALLY well or end up laid off when it fails to develop as they hope, so many issues to resolve.
Also: how often do you mop your floor Karst45?
Do you let it get dusty?
Dust leads to reduction in solar efficiency.


As for affordability: how long is a piece of string?
Depending on how good your tiles are, the application they are in, and the local environment (such as angle of sunlight onto the panels) determine the total power produced.
The quantity and price of power they generate is also locally determined and decides how long they take to pay for themselves. Then you get the issue of how long do they live for? will they even last long enough to actually pay for themselves?
And then there is maintenance... can you identify flawed panels to replace them? how much does this system cost?


Also: interesting fact: i've seen products like the one you just described, the tiles being about a meter by a meter (3 foot each way) and fitted onto roofs in london by a certain company...
You don't walk on them though, but they are modular, and fitted on site.
Interesting fact: buisnesses use them to reduce power costs, but i understand the lifetime value return on these panels is only 50% of their initial capital outlay (ie they only make back their cost plus an extra 50%), but that increases after establishment you move to replacing old panels without having to fit new wiring or mounts and so forth.
But again: this is based on increased costs for energy over there, and also government grants to move to renewable energy... without these benefits they'd be better off paying their bills and investing their money elsewhere, which is what many businesses would rather do.

Renewable energy is a nice idea, but isn't ever going to develop our economies beyond the current day, it's just not efficient enough, and there isn't any money in improving it because while oil gets more expensive, we have less money to spend ON other alternatives, because we still are reliant upon it.
The odds of our ever developing viable alternatives depend more on government investing HEAVILY (think the healthcare budget) into proper research than they do individual users making the switch.

Most rooms normally have pale-colored tiles, and the light that is reflected off the tiles is a noticeable part of the total lighting of the room. Photovoltaic cells are by definition, as you might imagine, black. Light that would normally be reflected back up into the room by a pale-colored tile is going to be absorbed instead by a photovoltaic tile. This will mean that you will have to turn up the lights slightly to maintain the same level of overall brightness in the room.

Since any photovoltaic cell has less than 100% efficiency, and any light bulb has less than 100% efficiency, then whatever amount of energy you had to spend to turn up the lights is going to be much more than the amount returned by the photovoltaic cells.

You could say, "well, I don't have to turn up the lights... I'll just accept the lower light level." That's fine, but you'd save more energy by just turning the lights down by the same amount.

If your floor tiles are black anyway, then maybe you might get a slight return on the photovoltaics. But I doubt it. And almost certainly not enough to justify the added cost over regular tiles (however small that might be).

Even given perfect efficiency, you couldn't produce more power than a fraction of what your light fixtures consume. A decent sized floor might produce tens of watts, but it'll need wiring and a power converter to push that back into the building power system. With the efficiency losses of having a high-durability high-traction surface and dust and dirt and the low intensity of indoor lighting compared to sunlight...I doubt something like this would ever recover nearly as much energy as went into producing it.

Also, covering your floors with dark tiles will make the place harder to get well-lit. You're much better off going for more efficient lighting.

Photovoltaic tiles aren't hopeless, though. Make them self contained with LED lighting and they could provide distributed low intensity lighting when the main lights are turned off, improving safety and providing interesting nighttime effects without a lot of installation fuss. They just aren't going to save much on the power bill.

Better off doing photovoltaic roofing or siding, on appropriately oriented faces.
If you keep the photovoltaic siding above ground level, you won't need to worry as much about people causing damage to your photovoltaics.
Still not perfect, but more efficient and more effective than photovoltaic flooring would be.

When you think about it, having a photovoltaic roof is a pretty good idea. "free" energy and you spend less energy keeping the house cool. The only real challenge is preventing weather damage. But that isn't much of an issue in some climates like Vegas.

It still amazes me that white roofing is considered a recent invention.

you should realize first that the primary uses of energy by humans are for:
- heating/cooling
- travel

electrical lighting is not all that energetic. don't get me wrong the sun dumps 3,850,000 exajoules (EJ(Exa = 10^18)) per year onto our planet.
but capturing that energy has already been pointed out to be barely sustainable when the panels are on the roof.
but better isolation and heat pumps or better engines for our cars (or work from your home)

this reminds me of the plume of smoke aircraft wheels give of during touchdown.
yearly there are alot of people who think they have found a solution to this but they fail to realize that the half inflated(because they heat up so much during takeoff/landing that the air expands) tires of a jet plane have the most wear and tear during the taxing from/to the runway not during takeoff/landing.

so perhaps tiles that are white to normal light but black to IR light so they absorb it and become warm, i love standing on warm floors so there's that too. if you combine that with windows that only let the IR light in and not out(those already exist) and you might have something. of course that only works in colder climates.

Actually there some pretty easy alternative for electrolysis of water in diesel engine truck. Apparently producing hydrogen and oxigen from water with the excess power created by the engine while idling or "cruising" and injecting the said hydrogen when the engine is on load (accelerating) make for a fuel economy of about 5% And it relatively inexpensive to work/do. Make me wonder why there not more of those concept on the road.

(Tivia, must highway truck hold about 300L of fuel if we say they save about 2-5% of fuel that mean they save 6-15L per refueling. average fuel price (here in Quebec) is around 1.40 CAD per liter. So 8,40-21$ Multiply this by the number of time you fuel your truck per year (lets say once a week but probably more) so 436.80-1092$

So the device could cost as much as 1000$ and still be worth it if it last at least 2 year but with a simple device as electrolysis (and a few solenoid) it should last longer.

eeee.... sorrrrry! i tend to get carried way when talking about technology in the automotive sector.


Mopping? what that?. Some stain could actually act as magnifier


For this one am serious when i say i dont understand the expression.




Well what would actually do a "mass furnance" kind of heating. Heated floor, YAY! But i understand they are not designed to be floor. The curiosity was more about if the return in power would be noticable.



Seem like an interresting concept for some lightning effect i was planning to do. tell me more!



Fun fact. Having a sun tracking device increase the efficiency of the solar panel by a fair amount (sorry i dont have the date on this) even if some of the energy produced is used to drive a motor.



Well it was probably overlooked because some people weren't used to white as a color. Traditionally roof were made of leaves or brick. so color were, dark gray, green, "pale brown", and red. The Egyptian were using white powder (i think it gypsum) to cover their Pyramid. So maybe they knew something we didn't



Well some leed project already use those concept, A dark painted mass wall who receive heat during the day an release it during the night when it colder.

That and geothermal cooling, it surprisingly efficient, and who know you may drill into a oil rig


Was wondering if anyone had some way to calculate how long it would take for a Ice "pool" to melt if exposed to a 10°c temperature.



P.s. Sorry for the wall of text

Hydrogen leaks trough every matter, and is a big ozonekiller. IMHO not suitable for widespread use.



Oh, it is.
The "only" or last big problem is to store energy in huge amounts.



Um, no. Economy doesn´t work this way. If something gets too expensive, it will be replaced by something cheaper.



Or to cut those heavy subsidies on outdated tech like coal or nukes, so the alternatives easily get more attractive.





Sadly no. Brightness inside houses is magnitudes below outside. So no perpetuum mobile here.
As Arioch said, you´re better off to furnish your home in light colours.

Plus the fact that your lights, in their primary energetic function as heat dispensers are already contributing to your ships climate. So basicly they are already invoked into a renewable cycle including heatpumps and life support systems.

you guys are aware that photo voltaics are not limited to big chunks of silica with wiring, right? there are quite a few recent innovations in the area, some of which include stuff like improved efficiency, wide angle absorption and flexible material....right?
so, basically paint on the roof on a wire mesh and you got photovoltaics, it had rather low efficiency(comparable to older silica slabs) but high angle if i recall correctly.

It doesn't change anything. The cheap photovoltaics are inefficient and short lived (and still not all that cheap), and even the expensive-but-efficient ones need huge areas and regular maintenance and replacement, and will perform poorly at actually supplying the grid when deployed on rooftop scales (a few big power converters maintained by the power company are far more efficient and effective than millions of converters each pushing a few hundred or thousand watts onto the grid, without regular maintenance and replaced on failure when the owner gets around to it). Then there's issues of weather and climate...photovoltaics will never deliver the power we need. (Unless we put them in orbit...which to be at all practical, would require setting up large scale orbital industry to make them from lunar or asteroid materials.)

And for the application mentioned in this thread, even 100% efficient photovoltaics would only recover a small fraction of the power that goes into the lights. Got two 60W bulbs producing 30 W of light, perhaps a tenth of that reaches the floor before being absorbed by other objects in the room (people are quickly going to learn not to point light sources at the pitch black floor if they like seeing their surroundings), and you recover perhaps 3W of power. A 3% increase in light bulb efficiency with the same light output will make a bigger difference.

Now if they could figure out how to make highway pavement act as even a weak photo voltaic array; and make it efficient enough to offset the cost of implementation in a rational amount of time, you'd have highways that pay for their own upkeep in electricity.

Think about it. It's a dark relatively flat surface that is widespread across most countries.

And that cars drive across all day. I think I'd want a surface that's going to face a little bit less wear and tear. Keeping roads maintained is already quite expensive enough when they're only made of asphalt and concrete.

To be fair, only a specific portion of it.

But actually looks like someone had a better idea than the expected photo voltaic cell for using asphalt as a solar collector:

http://www.sciencedaily.com/releases/20 ... 135702.htm

http://buildipedia.com/operations/engin ... ure-is-now

No, pretty much all over it. But that might be due to the colleges and universities in the area...

But seriously, do you expect people to keep their tires on narrow "traction strips" or something, not leak any oil or grease, and avoid tracking dirt onto the road? I'm not seeing any way to make photovoltaic roads that isn't going to be horribly expensive (we can't even keep up with the damage weather causes to normal roads around here), even less efficient than conventional approaches to photovoltaics, and fundamentally less safe. And adding yet another reason to shut roads down for maintenance...




That might be practical in particularly sunny and warm climates, but it's not a very generally applicable solution. Around here, it'd probably be more economical to heat the asphalt for half the year just to keep the system from being destroyed by the winters a season or two after installation.

it would be even more effective in places like Australia where for the main part temperatures below freezing are rare

http://www.australia.climatetemp.info/

And we put all kind of abrasive on it so car dont slide on ice, And we use Show plow that mark asphalt.

But the idea would be nice. Maybe one day when car would drive on Magnetic cushion



But actually using road to make electricity could be achieved with this. http://www.youtube.com/watch?v=UmTln2N6PaI.

That only steals energy from vehicles. Vehicles aren't very efficient at extracting energy from fuel in the first place, due to having to move themselves around, work at small scales, and operate for extended periods of time with minimal maintenance, and stealing part of their output like this will only increase gasoline consumption and air pollution for a rather pathetic return.

the basic idea is actually workable, not realized very well though, adding photovoltaic roofing to build code would do one hell of a lot more...or for that matter for creating hot water, and heating buildings....as a side benefit if done right, it would keep the roofs clean during winter in countries that actually experience snow, that will create a ice below the roof problem though, might not be a net benefit when i think about it.

Which basic idea?

Photovoltaic panels will still get snow covered. And in any case, keeping light snow off the roof in sunny conditions isn't much of a benefit...snow is insulation, and only a problem when it accumulates so much that the roof can't hold it. The weight of that snow is a bit more of a concern for photovoltaic panels than for buildings.

Or when the damn stuff blocks a furnace vent.

Had that happen last year. Was not fun having to crawl up there to clear that off.

Regarding roads as heat sources:

#1 they only get hot in serious sunlight, thus rendering them useless in the winter pretty much anywhere that isn't Australia, Vegas or Africa.
#2 While they get hot they are attached to a rather large source of cooling, known as the ground, and there is no reasonable means to insulate this connection
#3 How hot do you think the road gets? If you want hot water, just build solar reflector dishes and boil the water on rooftops, easy!

All these things means that the invendors idea regarding 'easy cheap power' isn't likely to be an economic solution in most everywhere.

Curiously, in terms of control of power of an entire country, PV and other solar sources (without large heat capacitance that some major power plants have) have a major fault, specifically a single cloud running over the panel/effective focus area results in a sudden and major loss of power production, making maintaining voltage on a network scale remarkably difficult.

In fact, there are some solar energy plants that can run quite happily in diffuse sunlight, but due to operational problems - specifically major overheating problems if a patch of direct sunlight comes along - are not used as such.

Regarding 'paint on solar panels' The way PV works is basically similar to a diode, with sunlight 'pushing' electrons from one side of the system to the other. This means that effective output of energy is determined by how well the bits of silicon are in contact, and when you 'paint' your solar panels, the exact line-up and arrangement of the crystals are poor, so much so they are considered novelties at best by most engineers due to being more than 10 times less efficient than crystalline PV systems, while still costing 1/4 as much (generally)


There's more, but given what i've read about these PV panels until recently no one had developed panels good enough to last long enough to generate enough energy to pay for the energy spent MAKING THEM, and TBH I can't vouch for the quality of the panels found commonly on the market to the domestic consumer, so I couldn't tell you if the panels you look at while at the store will last long enough to actually help the environment, or if you'd be better off installing a wood-burner and planting a tree every year.

On the other hand, i have a crazy idea about setting up a business near the seaside, and mining some of the worlds best sands, using solar electrolysis to create hydrogen to run diggers, dredgers and trucks to collect the sand, a solar furnace setup to burn/reduce/melt/crystallise/purify the silicon, and then use the panels it makes to pump water up a hill to run a turbine to power the factory.
I figure once it reaches break even, it'd have 0 input energy, only minor output energy, and be able to produce panels to sell to the world without more than some old oil lubes (because we don't have alternatives yet) to burn in the process of making them.
Ofc to be shipped globally either we'd need PV sail-boat arrangements, or we could just call it quits and use a normal freighter... or are there enough green conscious captains out there that I could get normal people to ship the panels to their destination?
Decisions decisions.

Word of warning for more normal people, stay off American biofuels: Corn takes more energy to turn into quality ethanol than the ethanol contains itself.
Thus Corn based ethanol (the primary source of fuel in the states) is a bad way to go about making biofuel.
Suggested replacements? Sugar-cane or potatoes.

There will eventually be algal sources, but those are still in R&D. There's switchgrass too, but that's still in R&D as well, and completing the work will make corn stalks a viable biofuel.

The future is bright, but the present is bleak.

That´s a worldwide problem meanwhile.
For our german biofuel called "E 5", "E 10" and "E 85" thousands of squaremiles of jungle were stripped and replaced with monoculture. And as monocultures are prone to insect attack, they´re treated with sh*tloads of insecticides.
Plus, due to the aggressive ingredients older injection systems corrode on the inside, often resulting in a total loss.
Luckily, most people here refuse to buy this cr*p.


I respectfully disagree.
I´d rather suggest more research on algae and that kind of stuff. No soil should be abused for fuel, ever.