Increasing the Productivity of Solar Photovoltaic Systems

State-sponsored incentives have played a significant role in driving the demand for residential and small commercial photovoltaic (PV) systems. All state incentive programs are tied to the power rating of the system, though some states also offer energy production incentives. Unfortunately, there is a disconnect between the power rating of a PV system and the energy that system produces over its lifetime. It is extremely important to consider system productivity, which goes well beyond the efficiency of the components. System productivity is tied directly to the structure of the array, not just the efficiency of the components and the quality of the installation. This paper examines the issues associated with improving solar PV system productivity. The focus is on comparing a series-parallel array configuration to a series-string array configuration and the impact on energy production. Partial shade is used to highlight substantial differences between the operation of the two array configurations.