12W aluminum substrate: full string circuit DC36V 18W aluminum substrate: complete string circuit DC54V 20W aluminum substrate: 2 parallel 10 collection (2B/10C) DC30V 24W aluminum substrate: full string circuit DC72V 30W aluminum substrate: complete string circuit DC90V 36W aluminum substrate: complete string circuit DC108V 50W aluminum substrate: 2 parallel 10 collection (5B/10C) DC30V