Battery-based Energy Storage Transportation (BEST) is the transportation of modular battery storage systems via train cars or trucks representing an innovative solution for a) enhancing Variable Renewable Energy (VRE) utilization and load shifting, and b) providing a potential alternative for managing transmission congestions. This paper focuses on point b) and proposes a long-term transmission-planning model coordinated with both stationary and mobile storage units. The planning-problem objective function minimizes the total system cost, i.e., the sum of i) the investment cost of candidate transmission lines, stationary and mobile storage systems, and ii) the operation cost, including conventional generating units fuel consumption, load shedding penalty and BEST transportation costs. An alternative approach for BEST vehicle scheduling problem is implemented. The contribution lies in the accomplishment of the spatial-temporal scheduling of the mobile storage units by including the Number-of-nonzero mathematical function in the optimization model set of constraints instead of using additional binary variables as generally accomplished. The identification of either storage systems optimal location, or both optimal location and size of storage systems is also allowed. BEST usefulness is analyzed and discussed for a test-system emulating a reals system in China-Northwestern-grid with high VRE penetration divided in five regional areas, of which the most promising one for BEST implementation is identified.

Renewable energy has a crucial role in facing climate change. One promising strategy is the creation of energy communities that require active involvement from a bottom-up perspective. Their implementation is difficult, as they currently rely on local policies, community readiness, and technological availability. The objective of this paper is to provide a qualitative overview of energy community concepts and strategies at the European level. The aim is to identify common approaches that are framing the development of energy communities, and to understand the most successful steps leading to their creation and growth. To achieve this objective, a threefold methodology is provided: (1) an updated review on policies dealing with energy communities at the European and Italian level; (2) a qualitative overview of European-funded projects under the Horizon 2020 work program; and (3) a qualitative overview of some of the most successful existing energy communities in Europe. The results outline a series of considerations and lessons learned that are useful for implementing this transition pathway in a real case, which is also presented in the paper. The conclusions will identify some future directions of this research, particularly in relation to the results coming from the implementation of actions in the real case.

In medium-voltage distribution lines, lightning outages associated with indirect strokes are less frequent when surge arresters are installed at close intervals. In this case, the lightning performance is mainly determined by the line response due to direct strikes, usually assessed disregarding the effect of the lightning electromagnetic pulse (LEMP). This paper examines the influence of such an electromagnetic effect on the voltages across the line insulators caused by direct lightnings. The presence of both surge arresters and a shield wire is considered. By means of adequate modeling and numerical calculations, we show that the flashover rate due to the direct strikes is increased by the LEMP. The obtained results indicate that in the statistical assessment of the direct lightning performance of lines equipped by surge arresters and shield wires, the LEMP effect is not negligible and its accurate evaluation is hence required.

This paper proposes the application of a recursive stratified sampling technique for improving the assessment of the lightning performance of power distribution lines through the application of the Monte Carlo method. The accuracy of the results is expressed by means of the confidence interval of the estimated annual number of expected overvoltages. The paper shows the results for a single overhead line, with and without surge arresters, and the case of a feeder with laterals. The adoption of the stratified sampling techniques allows for a computational time reduction up to more than 75% with respect to a standard Monte Carlo procedure. The conceived calculation procedure is applicable to any type of network, regardless of the presence of non-linear devices and avoiding the application of any heuristic rule.

Buildings nearby urban overhead power lines are expected to reduce the number of direct strikes to the line conductors and also to attenuate the lightning electromagnetic pulse (LEMP) radiated by indirect lightning strokes. The statistical method described in IEEE Std. 1410 for the lightning performance assessment, as the other methods available in the literature, includes only the former effect. In order to take into account also the latter effect, in this paper the LEMP attenuation due to the buildings is represented by means of specific weighting functions applied to the LEMP analytical expressions valid for open terrain. For both the cases of ideal and lossy ground, the parameters of the weighting functions are identified through the least square minimization of the differences with the results provided by a finite element method model that is assumed as reference for the configurations analyzed. The weighting functions can be used for lightning return stroke current waveform and distances between the line and the stroke location different from those used for their identification with reasonable accuracy. Finally, the paper compares the lightning performances of a power line evaluated with and without the presence of nearby buildings.

In the usual practice, the evaluation of overvoltages due to direct lightning strikes to overhead power lines is focused on the representation of the effects of the lightning current injection, whilst the effects of the coupling between the conductors and the lightning electromagnetic pulse (LEMP) is disregarded. Motivated by recent results obtained for the case of a medium voltage line configuration with a shield wire, this paper extends the analysis to assess the contribution of the LEMP on the lightning performance of an overhead distribution line with and without periodically grounded wires and surge arresters. Moreover, the paper deals with the LEMP effect on the occurrence probability of flashovers on different phases, which is an important information on the service continuity of networks with isolated or compensated neutral earthing. A validation of the results is obtained by comparing the overvoltages calculated by the electromagnetic transient program including the model of the line illuminated by the LEMP and those obtained by a three-dimensional finite difference time-domain approach.