installation of pv systems in greece—reliability improvement in the transmission and distribution system

photovoltaic (pv) power systems are becoming one of the most developing investment areas in the field of renewable energy sources (res). a statement of the status quo of pv power systems in greece, and their contribution towards the improvement of power system reliability, is the scope of the presentpaper. siting and installation of pv power systems is performed according to a recent greek law, along with environmental and geographical constraints. meteorological data are computed, formulated and imported to appropriate software in order to simulate the pv units and generate their power output. data for unserved loads, resulting from load shedding during peak hours, are compared to the above estimated power production. assuming that a proportion of the eventually unsupplied power could be provided by the accessed power generation of the pv units, the reliability of both transmission and distribution system is improved. the impact on the transmission system is shown by an improvement of lolp and loep indices, whereas peak shaving for the interconnected greek transmission system (igts) is also illustrated. for the distribution system the impact is quantified using the distribution system reliability indices saidi, saifi, and caidi. finally, the resulting improvement is also expressed in financial terms.