Effects of large-scale photovoltaic power integration on electricity distribution networks

The public support in photovoltaic (PV) technologies and increasing markets have resulted in extensive applications of grid-connected PV, in particular in the consumer side and electricity distribution grid. In this paper, the effects of a high level of grid connected PV in the middle voltage distribution network have been analyzed. The emphasis is put on static phenomena, including voltage drop, network losses and grid benefits. A multi-purpose modeling tool is used for PV analysis in Lisbon and Helsinki climates. All network types studied can handle PV without problems with an amount of PV equaling at least up to the load (1 kW_p/household). The comb-type network showed the best performance. The PV is unable to shave the domestic load peak in the early evening hours but through orientating the PV panels both to east and west, the noon peak from PV can be reduced by 30%. PV integration reduces network losses positively up to a 1 kW_p/hh (100% of annual domestic load) level. For 2 kW_p/hh all but the comb-type networks demonstrate clear over-voltage situations and the annual network losses are much higher than without PV.