This paper deals with energy and economic analysis of grid-connected photovoltaic (PV) systems with storage. According to the current Italian market rules, the first goal is to calculate the capacities of PV systems and batteries corresponding to the cost-optimal solution. Then, cost-effective solutions are investigated to maximize self-consumption, minimizing grid injections. Simulations are performed for one year, starting from irradiance data and load profiles from office and dwelling house users in Italy.