Enel Distribuzione projects for renewable energy sources integration in distribution grid

Abstract The integration of the dispersed generation, based on constantly increasing renewable energy sources, is one of the biggest challenges of the modern distribution system operator. Enel Distribuzione, that operate the 85% of the Italian distribution grid with 33 million customers, connected more than 25 GW of dispersed generations, mainly based on renewable energy sources, in Italy up to 2013; these numbers are most impressive taking into account that the consumption peak for medium voltage and low voltage distribution networks was 40 GW during the 2007 (the period before the economical crisis and with very small dispersed generation connected). The original design of Enel Distribuzione networks is radial and does not consider interconnection of any generation with significant size. In a radial feeder, the power flows unidirectionally from a single source to the loads. The penetration of dispersed generation into the feeder can cause a flow reversal. This flow reversal violates the concept of “radial design” and has a significant impact on the operation of the feeder and, in particular, on the protection systems and on the voltage regulation. In this scenery, Enel Distribuzione implemented and is implementing several large area demonstrations to test innovative smart grid technologies, in particular for dispersed generation integration. In this paper, two of these projects are presented focusing on the innovative solutions for voltage regulation and dispersed generation dispatching.