For those with excel my way of comparing solar cell costs

[cyplesma]

I'm submitting this excel file for comparision only. I have bought cells from both of these suppliers, but you can use it to compare other suppliers of solar cells as well.

It also helps me do the math for the size of a panel I'll need to build for the cells I choose to work with.

http://www.otherpower.com/images/scimages/4112/solar_cell_comparision.xls"

If there's a big response for this kind of thing for a vb program I or whoever can certainly make one.

[Bruce S]

cyplesma;

    Excel really isn't needed, it'll pull into ooog as well.

Nicely done too.

Thanks for the spreadsheet.

One item: could you add the notes about the * in some of the cells?

Cheers

Bruce S

[fred480v]

nice chart buy cells from both but never looked at it like this  THANKS

            fred480v

[Nando]

You have Voc = 0.48 volts and for a 12 volts panel the PANEL Voc should be around 22 volts.

Unless your Voc is Vmp, then the number of cells for a 12 Volts panel should be:

17 volts /0.48 Vmp = 36 cells.

Why do you have 32 cells ?; for 15.36 Vmp volts -- Not good for proper 12 Volts battery charging ?.

Nando

[cyplesma]

I've been using 32 cells instead of 36, I either have great sun or none. So when I do have sun I can use 32 for the 15.36.

Plus, those volts are from the manufacturers, and I've noticed that when I do have sun I get .5 to .55 volts. so the .55 * 32 = 17.6.

I like to under estimate the voltage I get out of cells when doing my calcs.

[cyplesma]

ooog is that a spreadsheet in linux?

I forget what the * were even there, but checking their site they mentioned that those items may have small chips in them. (supposedly that doesn't effect the output, but it does make a few .010+/- amps difference).

[Nando]

17.6 Volts @ what current ?.

Nando

[amiklic1]

I use WB28 and WB29 cells in my panels, and in fact, higher voltage leads to more amps when connected to battery.

P = U * I (Power = Voltage * Current), and it's allways like that. If you lower the volts (as they re when you connect 19-20 VOC to the 12V battery with 12-13 V) you'll get higher amps.

[cyplesma]

I don't know exact current my multi meter doesn't read that high.

and I don't have a lot of panels.

I have one string (32) of wb-23a they max my amps on my multimeter but it's not enough to move a 60 amp meter (obvisously it'll take more then one string to do that).

the other cells I've bought from either of these places and off ebay are all kind of a hodge podge collection, that I'm just playing with for the moment. I just liek the way this spreadsheet made it easy to do a basic quick and accurate cost analysis. of course it doesn't include shipping.  8 )

other cell sources can be easliy added