Energy Assessment of Photovoltaic Distributed Generation in LV Distribution Networks

The present paper focuses on the assessment of potential penetration of distributed generation (DG) in LV distribution networks with specific interest on photovoltaic (PV) DG. The possibility to integrate this form of local generation with distribution networks has been previously investigated by the Authors taking into account the limitations posed by voltage regulation, overvoltage protections and current carrying capacity of electrical lines. In this paper the problem is studied from the energetic point of view. An analytical method, based on the extension of the Utilizability function, is proposed to determine two quantities of relevant importance for distribution planners and operators. One is the maximum PV peak power that can be installed in a LV feeder in order to supply all the energy made available by the PV array according to the MPPT (Maximum Power Point Tracker) operation. The other one, under the assumption that it is possible to adjust PV units output power in order to avoid overvoltage and overload (known the total PV surface of the installed DG units), is the PV energy that can be produced but not supplied to the LV distribution system. A case study is also presented to show some quantitative results.