My 24 255W panels have a combined output of 6120 watts. I regularly reach 6100 watts on a sunny but cold day. The voltage drop so far has been minimal. The larger the cable, the lower the drop. My 4 gauge aluminum wire is working great. I was worried once that I would break the cable when I was pulling it. But I got through that and have had no problems. If you use aluminum cable, just be careful working with it and be sure to use the antioxidant paste on it.