Solar Cells
Also see the Solar_Panels_at_Factor_e_Farm
Solar Cells
These are the solar cells that we have from Ersol
Soldering Contacts
Recommendations for processing:
* maximum of 24 cells per bypass diode
* solder joint
- tin-coated copper strips
- 2.3 mm x 0.15 mm
Bypass diodes - [1]
Diode, 8 amp, $2.25 - [2]
Air Mass Calculation
In winter, the sun at high noon travels through an air mass of 2.2. See calculator at
http://www.udel.edu/igert/pvcdrom/SUNLIGHT/AIRMASS.HTM
This means that the solar irradiance available to the solar cells is about 0.8 kW per square meter, compared to 1 kW per square meter in summer.
Soldering
- SN60 40/60 and SN 63 is widely available in the plumbing section at your local/global enterprise hardware store. SN refers to tin, thus 60%, and the rest is lead.
Technique is such that a low power iron or variable power iron is required. High power is generally for plumbing applications. High power will cause the solder to ball up and be of little use. The guide below is the most detailed description we have of how to solder the leads or "tabs" to the cells. If anyone has more info on this topic let us know please!
- WORKING QUESTIONS:
- 1. alternatives to lead? lead free solder that still works for this application? given the lifetime of the panels and amount of PB necessarily a huge factor?
- 2. Width of solder? many sizes available, usually .31 and .75 are widely available. No guides
Encapsulation
- Information on encapsulation from Ebay - [3]
Comment: item appears to be unavailable; 2 negative feedbacks on item not being delivered
Soldering Leads to Solar Cells
Practical Guides
http://www.sungroper.asn.au/project/solar-panel.html
and
http://www.goodideacreative.com/solarpanel.html
are the best guides so far.
Other:
- Homemade Solar Panels[6]
Further Information
From Richard Schulte:
Most of the guides I have seen have all said the exact same thing about soldering the cells together. The process seems to be simple and more time consuming than anything. When it comes to encapsulating, however, there is a large amount of variance, though more people use plexiglass than I had thought would. Several guides have suggested the same sealant:
http://pyronet.50megs.com/RePower/Homemade%20Solar%20Panels.htm
Edit: I've been informed that fiberglass resin is a polyester resin and will not hold the moisture out very well. The best thing to use, which I'm switching to is a aluminum epoxy type sealer called ALUTHANE which can be found Here. <http://www.epoxyproducts.com/e_nonepoxy.html>"
We need to make sure you have the right kind of soldering iron as well. It must be fixed at low temperature or have a variable temp, or else the kind of solder we are using will ball up. One site, http://www.mdpub.com/SolarPanel/index.html, suggested mounting them on pegboard, and using silicone caulk to attach them.