PV Gap

Marlene Said:

solar panels & solar cells?

We Answered:

solar cells convert sunlight into electricity

solar panels are giant panels containing thousands of solar cells

Gail Said:

How fast do solar cells convert light into electricity?

We Answered:

at the speed of light

Patsy Said:

Can the solar cells in solar panels be made into any shape or do they have to be flat?

We Answered:

The 2010 Prius will have a solar panel roof option. This panel is slightly curved to fit the form of the roof. There are also flexible PV panels

Typically panels are flat as they are directed at the sun (with a tracker) to maximize voltage generation. The PV panel produces max voltage when its perpendicular to the sun linght, a curved panel would always have some portion of it not perpendicular and so its efficiency would be reduced.

What dictates the use of flat panels is economics and efficiency. If you don't care about the loss of efficiency and can afford it you could make a panel that is a half pipe. It is far easier to make and sell a flat panel.

John Said:

Can I still use broken solar cells for building solar panels?

We Answered:

The issue with broken solar cells is that you have to measure the current capacity that you can get out of each one and calculate how many to wire together in parallel and in series to get the desired characteristics. It's the nature of solar cells that broken ones are perfectly fine except that they just have different performance characteristics and hence can't be wired in a uniform pattern. Shorted cells should be easy to deal with as well, you just break them into two or polish off whatever trace that shorted them.

Usually voltage differences are differences between the quality of the individual silicon wafers while current differences are due to the size of the fragment that's been broken off.

It used to be you could get the broken fragments for free and it was just a matter of putting a lot of labour into wiring them up yourself but now they sell the broken fragments by the pound so much of the financial advantage is gone. Also because you are also arranging broken fragments onto a panel, the panel won't be as efficiently covered with solar cells as a panel made with unbroken solar cells.

Sometimes you can just buy solar cells in bulk for a good price. Them come in a block of wax to prevent accidental breakage. It's a lot of work to melt them out of the wax and hand solder them into a panel but doing the labour yourself could save you a lot of money, however most of the savings in this approach aside from the labour is because you would be using inferior materials to mount them such as mounting the cells on a sheet of exterior grade plywood.

There are advantages to hand assembling solar cells into a panel. As you're measuring each cell or cell fragment, you can better match the voltage output of the cells that you're wiring together in parallel and better match the current outputs of what you're wiring in series rather than just assuming that each cell is the exact same voltage and current.

Dean Said:

Whtas the difference between solar cells and solar panels?

We Answered:

a bunch of solar cells make up a solar panel

Randy Said:

What are the advantages of using gallium arsenide in solar cells or solar power panels?

We Answered:

They have a higher energy conversion efficiency in white light than silicon cells do.
http://en.wikipedia.org/wiki/File:PVeff(…
from:
http://en.wikipedia.org/wiki/Solar_cell

So if cost is not important, but area for cells is very limited, then GaAs cells are better.

Stacking several different cells on top of each other (where the wavelengths that are not converted are passed through to a material that will convert some of what is left to electricity) are best and are called multi-junction cells. The Mars Rovers use these.

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Regards,

John Popelish

Mary Said:

what is the difference between solar cells and solar panels.?

We Answered:

A solar panel is made up of a series of cells. The number of cells in any one panel is dependent on it's size.
So you could say that a cell is singular and a collection is a panel.

http://www.darvill.clara.net/altenerg/fo…

^ fossil fuels..