Back Contact Module Technology

Back contact modules manufactured with MWT cells comprise a higher efficiency than standard x-Si modules made with H-patten cells, due to low fill factor losses of only 0.8%. The cell-module concept is a truly integrated concept with a simplified manufacturing process. The modules show high stability in reliability testing, with only 1.9% loss in relative power after 2000 hours of testing in damp heat. IEC61215 and IEC61730 certificates have been obtained. The MWT modules also show higher outdoor performance due to lower series resistance. The material costs are dominated by the conductive back sheet and conductive adhesive. Potential routes for cost reduction are discussed in this paper. Large scale production is now starting to take off, with MWT production capacity to reach up to 1 GWp in 2012.