This study seeks to quantify how much insolation varies over the span of a typical photovoltaic (PV) array. A solar sensor array was constructed and deployed at three locations where environmental conditions vary from full sun to highly restricted sunlight. Data was recorded at each location and then analyzed to find the effects of shading. In traditional series-parallel photovoltaic systems the total power output of the system is highly dependent on the full insolation of every cell. One cell with low insolation properties will drag down the current of an entire series string. Analysis of the sensor array data has shown that insolation varies substantially, even on an unshaded site. These findings should help, along with future research, to demonstrate the necessity of eliminating series strings from PV systems to increase energy production.