Solar Panel choice (1 Viewer)

[markymark]

Is this a suitable type of panel for the roof of the motorhome? ie photovoltiac.

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[pappajohn]

hi mark,

have a read of this

explains the different types and how good they are.

originally posted by diabalo a long time ago. :thumb:

Types of solar panel

There are three main types of solar panel in commercial production, all with some advantages and disadvantages. All three are based on silicon semiconductors - the difference is the form that the silicon is in. Panels based on other chemistries are under development. Cadmium telluride and copper indium diselenide panels may well appear in production soon, and there is also research being carried out on using the photosynthesis effect that plants use to convert sunlight to useful forms of energy. However, you are unlikely to come across technologies other than silicon for the time being, so we will just consider silicon on this page..

Monocrystalline solar cells are made from thin wafers of silicon, sliced from large crystals that have been grown under carefully controlled conditions. The cells are typically a few inches across, and a number of cells are laid out in a grid to create a panel . Relative to the other types they have a high efficiency, meaning you will get more electricity from a given area of panel - useful if you only have a limited area for mounting your panels, or want to keep the installation small for aesthetic reasons. However, growing large crystals of silicon is a difficult and very energy-intensive process, and so the production costs of this type of panel have historically been very high. Production methods have improved though, and prices have fallen a great deal over the years, partly driven by competition as other types of panel have been produced.
It is rather cheaper to produce silicon wafers in polycrystalline form, as the conditions can be less tightly controlled. In this form a number of interlocking silicon crystals grow together. Panels based on these cells are cheaper per unit area than monocrystalline panels - but they are also less efficient, and in terms of pounds-per-watt there is not a great deal of difference.
The newest type of panel is based on amorphous silicon. Here the silicon atoms are not ordered in a crystal lattice at all. The production methods are quite different - instead of growing crystals, the silicon is deposited in a very thin layer on some kind of backing substrate. Sometimes several layers of silicon doped in slightly different ways to respond to different wavelengths of light are laid on top of one another to improve the efficiency. The production methods are complex, but less energy intensive than crystalline panels, and prices should come down as panels are mass produced using this process.
One advantage of the very thin layers used is that the panels can be made flexible. Types are available that can be curved to the bend in a roof for example, or even attached to a flexible backing sheet so that they can be rolled up and put away when they are not needed! The disadvantage of amorphous panels is that they are not as efficient per unit area as monocrystalline panels - typically you will need nearly double the area for the same power output. Having said that, for a given power rating they do perform better at low light levels than crystalline panels - which is worth having on a dismal winters day. At least one manufacturer now produces a hybrid panel, where a layer of amorphous silicon is deposited on top of single crystal wafers. This gives some of the advantages (high power, but still efficient at low light levels) - and some of the disadvantages (not flexible and relatively high price) of the different panels.

 

[6pm Cowboy]

So, in relation to the above, what is 'photovoltiac' ?

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[atakd]

Have bought the same one off this seller and am very pleased with it. Buy at £159 as his prices fluctuate between 159 & 179.
Photovoltaic means a voltage is generated by light as opposed to some solar devices which simply act as a heat exchanger for warming liquid.

 

[656]

PV's are arrays of cells containing a Solar photovoltaics material that converts solar radiation into direct current electricity.

 

[6pm Cowboy]

So in effect all solar panels are photovoltiac. brings us back to OPs original question of which is best.

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[SIFTA SAM]

So, in relation to the above, what is 'photovoltiac' ?

Monocrystaline, polycrystaline and amorphous silicon are all photovoltiac.
Most materials that converts solar radiation to electrical power are deemed photovoltiac.


Roll-on the Revolution!

 

[pappajohn]

So in effect all solar panels are photovoltiac. brings us back to OPs original question of which is best.

monocrystalline are best and most efficient producing the most amount of electric for the panel size and are usually more expensive.

poycrystalline are the commonest and produce a reasonable amount of electric for the size of panel

amorphous are the least efficient and produce the least electric for the size but they are relatively cheap.

my polycrystalline is about the same surface area as the maplins 60w amorphous panel but mine is rated at 120w...double the watts and the price but the same size as the cheap one.

 

[6pm Cowboy]

I think I have read somewhere that there are two 'other' types. one that shuts down if any part of the panel is in shade and one that still works with the bit that isn't.

is this right ?

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