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Author Topic: Do solar paints exist that could be applied to buildings?  (Read 3433 times)

Offline Emilio Romero

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Sorry if I am way off the mark here, but It seems that one of the problems with collecting solar energy and transforming it into electricity is the wide area that needs to be exposed to the sun in order for the collection to be efficient.  If that is so, why not use in every house and building some kind of paint that does the job? And probably “connect” ultimately the paint to an energy collector?  If this is done in great scale, say also do it parts of roads and highways, will it not be easier to solve this issue?
Thanks

emilio

« Last Edit: 27/09/2008 10:39:39 by chris »


 

Offline techmind

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Re: Do solar paints exist that could be applied to buildings?
« Reply #1 on: 23/09/2008 19:34:38 »
While it's true that you need a fair sized area to generate a decent amount of electricity, the biggest problem is the cost of the photovoltaic materials. And much of that cost comes from the energy required to purify the silicon and make the cells in the first place.

The highest efficiency readily-available (silicon) cells are only 18-20% efficient, so you could get 200W per square metre absolute maximum. Cheaper (but still expensive) cells manage a bit over half that efficiency.

There is ongoing research into polymer (plastic) based solar cells which could be cheaply deposited onto large reels of plastic film ... but these would be much lower efficiency still (even more area for given power). And it's early days yet.
It'll never be quite as simple as paint-on, as fundamentally you're always going to need a layer structure with two electrodes (metallised layers) separated by one (probably two) or more semiconducting layers.


Or are you suggesting that the paint would simply collect light (ie a light-pipe) and concentrate it for delivery to an existing-technology PV cell? In which case you run into huge problems of optical losses.
 

Offline Pumblechook

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Re: Do solar paints exist that could be applied to buildings?
« Reply #2 on: 23/09/2008 21:39:44 »
Typical average output from a panel is 10% of peak in Britain and at most 15% in the sunniest regions of the world.....Obviously no output when it dark and peak is only really reached under bright conditions when the Sun is square on to the panel.  So a 200 Watt peak output panel produces only 20 Watts on average if measured over a full year.

This make solar electricity expensive.

There is  a German product made by Alwitra... Which is combined with a plastic roofing material called Evalon.
 

Offline techmind

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Re: Do solar paints exist that could be applied to buildings?
« Reply #3 on: 23/09/2008 21:51:47 »
Typical average output from a panel is 10% of peak in Britain and at most 15% in the sunniest regions of the world.....Obviously no output when it dark and peak is only really reached under bright conditions when the Sun is square on to the panel.  So a 200 Watt peak output panel produces only 20 Watts on average if measured over a full year.

This make solar electricity expensive.
Agreed. Very long payback time.
 

Offline Pumblechook

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Re: Do solar paints exist that could be applied to buildings?
« Reply #4 on: 24/09/2008 00:36:04 »
I don't think solar panels ever reach payback.  They will fall apart before you reach payback and the overall cost has to include batteries (limited life), inverter and a control system. 
 

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Re: Do solar paints exist that could be applied to buildings?
« Reply #4 on: 24/09/2008 00:36:04 »

 

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