Wiring solar panel module strings without a return wire.

It is possible to connect a string of solar modules without a return wire. In the diagrams below, the typical method for wiring strings is shown in the top illustration, with a return wire. The lower two diagrams illustrate how to wire a string – leapfrog style – without using a long return wire.

On a single string with a small number of panels the return wire doesn’t add much expense, but on a commercial or utility-scale install with thousands of feet of return wire this could make a significant difference in cost. As far as installation, on a ground mount or a tilted flat roof mount with easy access to the back of the panels this could be an easy alternative connection method. However, on a fixed flat roof mount the actual wiring may be difficult to accomplish since more than one module needs to be held up to make the connection. Experiments, anyone?

alt. string wiring