The paper reports an overview of main issues related to hosting capacity and harmonic disturbances caused by EV penetration in a Smart Grid, taking into account renewable energy sources and energy storage systems as well as non-linear loads. A new mixed deterministic and probabilistic method based on algorithms and new control strategies, able to perform EVs charging controls, is presented. The methodology shows as it is possible to achieve high levels of power quality thanks to a pre-evaluation of harmonic disturbance. Studies on real networks are reported in order to carry out indices able to define a preliminary assessment of the network hosting capacity. Suggestions and guidelines about the management of EVs charging stations are proposed and discussed in order to properly integrate them in a smart grid concept.

This study presents a cost comparison between commercially available high‐voltage DC (HVDC) and extra high‐voltage AC shore connection (±320 kV voltage source converter and 420 kV–50 Hz single‐core and three‐core cables), for a 1 GW offshore wind farm cluster, considering transmission distances up to 400 km. The HVDC system is a point‐to‐point connection whereas multiple AC intermediate compensating stations are envisaged for AC when needed. Capital costs are evaluated from recently awarded contracts, operating costs include energy losses and missed revenues due to transmission system unavailability, both estimated using North Sea wind production curves. Optimal AC intermediate compensation, if any, and reactive profiles are also taken into account. Resultsshow that HVDC has lower transmission losses at distances in excess of 130 km; however, due to the combined effect of lower AC capital cost and unavailability, using three‐core aluminium cables can be more convenient up to 360 km distance.

The use of diesel generators to supply electricity to small remote islands is both costly and environmentally troublesome. On the other hand, small island networks pose peculiar stability and reliability problems when renewable energy sources are added. The paper regards the installation of an hybrid power plant (phortovoltaic, PV, plus lithium battery and synchronous condenser) in Giglio island, to replace existing diesel units. The paper discusses the general overview of the project and presents steady-state and dynamic simulations of the proposed energy system. Results evidence the advantages of the proposed Giglio hybrid power plant over existing diesel generators in terms of reduction of both pollution and energy costs, also allowing to fulfill the N-1 network security criterion. At the same time, results underline the need to install a properly sized flywheel in order to assure the stability of supply.

This paper presents an experimental application of LiFePO₄ battery energy storage systems (BESSs) to primary frequency control, currently being performed by Terna, the Italian transmission system operator (TSO). BESS performance in the primary frequency control role was evaluated by means of a simplified electrical-thermal circuit model, taking into account also the BESS auxiliary consumptions, coupled with a cycle-life model, in order to assess the expected life of the BESS. Numerical simulations have been carried out considering the system response to real frequency measurements taken in Italy, spanning a whole year; a parametric study taking into account different values of governor droop and of BESS charge/discharge rates (C-rates) was also performed. Simulations, fully validated by experimental results obtained thus far, evidenced a severe trade-off between expected lifetime and overall efficiency, which significantly restricts the choice of operating parameters for frequency control.