It is both a discipline and technology involving the production of electricity by converting solar radiation. Materials used for this purpose are semiconductors with special properties, such as silicon – the second most common element in the Earth. Photovoltaic cells produce direct current, which is subsequently converted by an inverter into alternating current supplied to the grid.
Photovoltaic systems have simple construction and they are easy to use both in household conditions as well as in industrial environment. They don’t generate noises and many years of researches point out their reliability and durability in the 20-30 years period after manufacture. Photovoltaic systems do not require the maintenance, and the installment is possible on any surface, which is suitable for receiving solar energy.
Currently, the market offers a three – generation photovoltaic systems of the third generation. The first and most common one are cells made from silicon. The second generation offers more advanced thin layer semiconductor technology, made of amorphous silicon, cadmium telluride or chalcopyrite. It is a less efficient technology, but it allows to reduce the cost of manufacturing cell. Third-generation cells are organic dye-sensitized. To obtain higher voltage and power they are connected in series or parallel modules and panels.
Photovoltaic is booming in the world: at the end of 2006 it has been installed 1,581 MW photovoltaic panels and their cumulative power has amounted 6 890 MW. Five years later, in 2011, it has been already installed 27 650 MW of solar cells and accumulated power has grown to 67 350 MW. The leader in installed capacity of photovoltaic panels are Germany (24 700 MW of solar panels).
Currently, based on the assumptions of National Renewable Energy Action Plans, it is expected that in the European Union, by 2020, the total installed photovoltaic power capacity will be 84.38 GW. This means that photovoltaic is well on the way to build an effective and significant component of the UE energy system. The Czech Republic has already installed more than 1,500 MW of PV, on the German market it is installed nearly 11 thousand MW. However, the development of technology, highly depends on the national legislation, support systems and the financing availability.
Photovoltaic plants in Poland
The total installed capacity of PV in Poland, at the end of 2011, amounted to 2.3 MW, according to data from the Energy Regulatory Office. Due to the lack of adequate support system, Poland failed to realize investments similar to those from Germany or from Czech Republic. In October 2011, in the Wierzchosławice community (Lesser Poland province), the first and largest photovoltaic farm has been built. It has a capacity of 1 MW and included 445 solar panels on a total area of 2 hectares. In recent years, smaller installations has been formed, primarily localized on the roofs of buildings. New legislation could open the way for financing photovoltaic investments.