Analysis of the Impact of PV Distributed Generation in the Transmission-Distribution Interface Demand

The growth of distributed generation in Brazil has become a matter of concern to distribution utilities due to several reasons, including the impact that it might have over the Transmission-Distribution Interface (TDI) demand. Since the demand forecast of each TDI point must be correctly signalized, with penalties due in case of lack of accuracy, the expansion of small-scale PV systems - and its inherent intermittent behavior - may result in financial losses. This paper aims to investigate such impacts, proposing a methodology to assess increased risk of penalties and thenceforth avoid it. The methodology was first applied to identify, from the 51 TDI points of a Brazilian utility, the ones of greater concern (16). Further analysis was then applied to a selected one, indicating that (i) the probability of penalties becomes relevant for a PV penetration corresponding to 30% of the currently declared demand; (ii) when it occurs, reducing the declared demand in 2% is an efficient solution to mitigate penalty risks.