is shown running along and above the course of shingles 140 a distal end 158 of cable 150 is adapted for connection to a source of ac power usually through a suitable controller 200 fig7 a suitable plug or interconnection means not shown would typically be provided the plug or interconnection means form no part of the instant invention and suitable plugs or other interconnection means are well know to those skilled in the electrical arts electrical drop down leads or pigtails 152 descend from cable 150 at regular intervals the interval is chosen to match the width of the shingles being powered typically 36 inches it will be obvious that other length shingles could be used and the spacing of pigtails 152 along cable 150 could be adjusted accordingly each pigtail 152 terminates in an insulated slide on connector 154 typically male and adapted to slidably connect to female connectors 142 fig4 on each shingle 140 cable 150 is a flat ribbon type cable which allows it to be laid along and below courses of shingle without causing an excessive bulge or ridge this helps not only protect cable 150 but minimizes potential damage to the shingles themself on roofs where people occasionally must walk the flat construction of cable 150 also allows it to be folded so as to change its direction of travel at a corner 156 this allows.