Over the last two decades, solar photovoltaic (PV) systems have evolved from a small-scale niche market application to a major electricity source. Although the share of most annual PV production is less than ten per cent even for the most aggressive adopters, PV systems have started to create operational and planning issues for utility operators. In this chapter, we discuss PV integration issues both at low- and medium-voltage levels. Distributed PV systems at low-voltage networks lead to power quality issues, while large-scale PV farms have impacts on transmission network and generation assets. Then, we present a comprehensive overview of demand-side management (DSM) techniques and examine how DSM can be used to aid PV integration. In the last section, we present two experimental studies: (1) direct-load control of an air conditioner unit and (2) load shifting of a water heater. It is shown that such flexible loads can aid PV integration and increase PV self-sufficiency levels.