INTERCONNECTED Photovoltaic systems

The grid-connected photovoltaic systems supply the generated electricity with electrical charges and the excess electricity if any is transmitted and sold to the grid. However, in case the energy from the photovoltaics is not enough to cover the loads, then the network provides the additional energy. Thus in interconnected systems there are two electricity meters. One measures the energy supplied to the grid and the other the energy supplied by the grid. Another fact of interconnected systems is that it reduces the initial cost of installation as well as the cost of maintenance.

AUTONOMOUSLY Photovoltaic systems

Today there are a variety of small photovoltaic systems in telecommunication station antennas, cottages, water pumps, ski resorts, caravans, lighthouses, weather stations, outdoor lighting fixtures, boats and others which become energy autonomous. Of course there are batteries that store the generated electricity, while in case we have AC loads there should be an inverter in the system that will convert the DC to AC voltage. When autonomous photovoltaic systems are combined with another renewable or conventional source of electricity (wind turbine, generating pair, etc.) then they are characterized as hybrids.

HYBRID PHOTOVOLTAIC SYSTEMS

These are wind turbines-photovoltaic, autonomous systems that consist of the PV array in combination with other energy sources such as a diesel generator or other form of RES (eg wind turbine).