Photovoltaic system for the funicular of Leghorn, Italy

The PV system for the Leghorn funicular railway was introduced in service at the beginning of 2000. It has the aim to demonstrate the possibility to increase the reliability and availability of the funicular service solving the problems of the continuity of the service. The PV system is a 36.5 kWp grid connected unit which, in case of grid break-down, operates as a stand alone unit recharging a 400 Ah-380 V lead acid storage battery through a DC/DC converter in order to maintain the funicular operation. The PV system is composed by 348 modules of 105 Wp-24 V nominal wired in series at groups of 12 units. The modules are fully integrated into the roof of an adjacent parking. During regular service the energy produced, about 45000 kWh per year, is used by the funicular or sent back to the grid. In case of grid breakdown, the PV system recharges the lead acid battery, which allows the continuity of the service.