... blue color Reliable parameter 4W Polycrystalline Solar Cell with tabbing wire for DIY Solar Panel Electrical Property 1, Solar Cells ... Low warpage and bowing 8, REACH-SVHC and RoHS compliantHow to soldering solar cellsStep 1 Select solar cellsStep 2 Single solar ... other raw material for solar panel, like pv ribbon wire (solder tabbing wire, bus wire), flux pens, silicon, junction boxes, solar cable, ...