Residential rooftop photovoltaics (PV) systems have great potential to supply part of the growing energy demand. However, its non-dispatchable, fluctuating, and intermittent characteristics may negatively impact the power quality and reliability (PQR) of low voltage (LV) distribution feeders. Large amounts of non-dispatchable PV sources, if integrated in a distributed way, can reverse the power flow in the feeder and lead to overvoltages. In diesel-based autonomous systems with high-penetration of PVs, the reduction in net load can significantly increase the wear and tear on the diesel genset(s). Therefore, connection of only a modest amount of PV is currently allowed at the LV level without a prior impact-assessment study. This book focuses on the detrimental impact of high penetration of PVs on LV systems and on the remedial actions that can be taken to increase PQR and the displacement of fossil fuels in diesel-based autonomous systems.