The last two decades have seen an unprecedented development of distributed energy resources (DER) all over the world. Several countries have adopted a variety of support schemes (feed-in tariffs, green certificates, direct subsidies, tax exemptions etc.) so as to promote distributed generation (DG), especially those exploiting renewable energy sources (RES). Under these circumstances, Distribution Network Operators (DNOs) are experiencing a strong pressure to respond to an often excessive demand for access to the network, while at the same time ensuring that DER connection does not violate the technical standards of the networks. To address this need in a timely and effective manner, simplified methodologies and practical rules of thumbs are often applied to assess the DER hosting capacity of existing distribution networks, avoiding thus detailed and time consuming analytical studies.
The scope of the CIGRE WG C6-24 was to study the limits of distribution feeders for hosting DER and the derivation of practical guidelines for the connection of DER. For this purpose, the approach adopted by the WG was to study the technical evaluation practices adopted by DNOs all over the world, in order to identify suitable rules and methodologies, as well as the means currently available to increase the hosting capacity. Main results of this investigation are summarized in this Technical Brochure.