IV curve testing is a diagnostic method that measures the current-voltage relationship of solar panels under controlled conditions. By plotting how a solar module behaves electrically as the load changes from open circuit to. Solar Cell I-V characteristic Curves show the current and voltage (I-V) for a specific PV cell, module or array, therefore giving detailed description of its solar energy conversion efficiency and capability which is critical in defining the device's optimum performance. Different measurements can. The Ossila Solar Cell I-V System is a low-cost solution for reliable characterization of photovoltaic devices.