NEW ANCILLARY SERVICES REQUIRED TO ELECTRICAL STORAGE SYSTEMS FOR CORRECT NETWORK PLANNING AND OPERATION

The growing of electric energy produced by distributed energy resources (DER) and, more in particular, from renewable energy resources (RER) in particular, with the need to reduce grid transmission costs and the general reduction of incentives for the produced energy, have turned the economical convenience for end users from the delivery of energy to the grid to self-consumption. In this change, manufacturers effort is aimed to both introducing in the market new technologies, mainly battery electric storage system and acting at Standards level. Even with actual low numbers, also DSOs and TSOs are interested in storages applications, because of their potential as deferral investment, security congestion management, losses reduction, power quality, voltage control etc. Consequently, in some countries new technical rules have been issued in order to facilitate the integration between renewable energy resources and storage needs, both in MV and LV distribution networks (i.e., Italian StandardCEI 0-16 and CEI 0-21). The paper describes the main aspects related to the integration and management of the BESSs in (transmission and) distribution grids, starting from those similar for traditional generating plants, to other ones, not new as concepts, but surely different concerning the implementation for the DSOs (TSOs)