With some basic calculations, it seemed we could install a solar system ourselves for a little less money, with no future utility bills. This will help determine the size (number of panels) you’ll need, as well as the orientation of your system. → Solar System ComponentsTrevor RaabFirst, check with your municipality or authority with jurisdiction to see what version of the National Electric Code (NEC) they are using. Parallel or Series ConnectionsThere are two options for how both batteries and solar panels can be wired—in parallel and in series. For solar panels, the one you choose depends on two things: the maxi­mum PV (photovoltaic, or solar) input for your inverter, and the solar array location and shading.