Because this grid-tie inverter (GTI) is low DC Voltage (10.8 - 30) you have to make sure the solar panels' output is within these numbers. You may need to wire the panels in parallel to keep the voltage down. I thought this GTI was Dead on Arrival, but then I realized the two 100w panels I have were in series, meaning the voltages add up. You need to look at the Voc numbers. Mine are 24.5v, so two of them is 49v, which is higher than the input for this GTI. *Luckily, I was easily able to switch the panels to parallel, and their output stayed at 24.5v, barely within the rated input tolerance.* Maybe the other reviews that say the GIT was DOA did not realize this?