Combined cycle
The electricity generated by photovoltaic panels is of continuous type. Since the national distribution system is based on alternate current an electronic device, the inverter, is capable of transforming (and therefore used) direct electricity to alternate. Energy is transferred from a photovoltaic power station to users through specific devices, necessary to transform the current produced by the modules and adapt it to the needs of final users. All of these devices are called ‘BOS’ (Balance of System) and include, in addition to the inverter, the transformer, the switchboards and auxiliary plant systems.
Photovoltaic conversion, which was developed at the end of the 50s within space programs, is considered a technology that can significantly help meet the increasing global energy needs without greenhouse gas emissions.
This is why it attracts large investments, both for the construction of systems and for research and development of new materials and technologies that can reduce generation costs for each produced kWh.
Specifically, in the last few years the installed capacity worldwide, which was only 1,000 MW in the year 2000, is growing at an extremely fast rate. Major international energy agencies estimate that in 2020 the PV installed capacity worldwide will be as high as 56,000 MW, with an electricity production capable of meeting almost 2% of world demand.
Italy is not excluded from this development, since in this country distributed generation is growing at a pace that could have never been predicted just a few years ago. For example, in 2008 and 2009, about 70,000 PV systems were installed in Italy.
These plants have a limited capacity (up to 20 kW), allowing each home to become a small power station capable of meeting the needs of the family and, at the same time, to inject power in the public grid.