With the significant lack of sources of energy, every type of technology which produces energy is useful. The use of renewable sources of energy is therefore our obligation. One of the most important renewable energy sources is solar energy.
 
Solar enery can be utilized with the help of photovoltaic systems, which virtually have the ability to convert solar energy to electrical.
 
Architecture's structural framework has directly been influenced and this as a result has the embodiment of photovoltaic features in its facade.
In this way the building becomes a producer of energy.
 
The basic types of electrical energy producers are: ( photovoltaic cells )
 1. The single crystalline silicone cells,
 2. The multiple crystalline silicone cell,
 3. The formless silicone cells.
 
Three types of photovoltaic systems are distinguished.
 
1.  The autonomic or non linked systems with the P/V system network.
2.  The linked P/V system with the network.
3.  The hybrid P/V system.( hybrid systems with air hybrid systems with liquid).
 
In all cases the photovoltaic systems can be listed in any architectural application in combination with glass or independently, in different areas of the impendent building or building lot ( atrium, ceiling, facades, covers, venetian blinds etc.) with consciouness for the conservation of energy, soundproof insurance, heat insulation and the satisfaction of the beauty of each building.
 
Finally, within the bounds of the obligations of the current project, it is significant to mention that energy research for the area of Elefsina, with the use of RETsreen International and Relux programes was conducted.
 
The results of this research showed that the photovoltaic systems which are under research, recommend a livable and financially profitable energy solution for the area of Elefsina.