Some time ago I bought some PV cells (6"x3", from rebeccayi0904 on ebay, very nice seller!) with intention of building a PV panel (after reading a plaethora of instructables on solar panels here!). While testing the individual cells out there in the sun I noticed that they got quite hot. I then realized that PV panels convert to electricity only about 12% of the solar power that gets to them. What about the rest? It becomes heat (about 88%). I figured that perhaps in the same surface one can harness both the electricity and the thermal energy of the panel....
Step 1: Overall Panel Characteristics, Items, Etc.
I am not going to repeat all the details on how to build a solar panel, there are plenty of other instructables for this (search tool is your friend!). I will give some basics, though... and then focus more on the "hybrid" nature of my panel (PV + thermal).
- about 0.5 m^2 area, at a maximum of 1 kW/m^2 of irradiation and 12% efficiency this should produce UP TO 60 W of electrical power. (at the same time this means that about 440 W of thermal power could potentially be harnessed!).
- 36 cells, 3"x6". Cost: about $150 from rebeccayi0904 (ebay, nice seller!) for 80 cells (used 36 for this panel).
- aluminum backplate (26"x32", can't remember thickness): about $10 in a sheetmetal store.
- small roll of Begquist sil-pad 400, cost about $50 from ebay (can't remember seller)
- glass front cover, about $15 at the hardware store
- aluminum rails for borders, about $12 at the hardware store
- about 25 feet of 1/4" copper pipe, about $20 at the hardware store
- some 2-3 tubs of silicone caulk
- aluminum flux paste from McMaster-Carr (about $30, but you can buy a smaller quantity, I only used about 1/20 of the tub)
- a 12 V water pump, search on ebay "12 V pump laser & cpu cooling", cost about $10.
Caution: Aluminum Flux Paste is a very nasty material. It contains fluoride and if handled improperly it can cause serious harm to you. Read all instructions and the material safety data sheet (MSDS), and if you are not 100% confident that you can work safely, do not.