A review of technical issues on the development of solar photovoltaic systems

Today, photovoltaic (PV) plants are receiving a significant attention due to their intrinsic ability to directly transform solar energy in electrical energy. However, electricity generated from PV plants can rarely provide immediate response to load demand, as these sources do not deliver a regular supply immediately compatible with consumers' needs. Recently, an important attention has been devoted to the use of energy storage in grid-connected PV plants, with the objective of adding flexibility in load management and overcoming some important power quality problems of real distribution grids. This makes PV plants more useful and attractive. Several battery management techniques have been underlying as a way to create more price-responsive demand and as a way to integrate PV plants more effectively into power grid. However, the development of energy policies constraint the wider deployment of PV systems. In this paper, various sizing, modelling, maximum power point tracking (MPPT) methods have been reviewed for the efficient operation of grid-connected PV systems. Dispatch strategies for stored energy that maximize the financial value of battery-PV systems along with several optimization techniques are discussed. Power quality and control technology issues of grid-connected PV systems are also covered. The economic and environmental benefits of grid-connected PV systems are underlined and operational and maintenance issues of PV-battery power systems have been included. The present paper aims at reviewing some technical challenges on the current state of PV systems based on energy policies, various cell technologies, MPPT and converter/inverter technology, energy management and scheduling techniques, reliability, power quality and control systems issues.