• Energy Research

This paper introduces distributed algorithms that share the power generation task in an optimized fashion among the several Distributed Energy Resources (DERs) within a microgrid. We borrow certain concepts from communication network theory, namely Additive-Increase-Multiplicative-Decrease (AIMD) algorithms, which are known to be convenient in terms of communication requirements and network efficiency. We adapt the synchronized version of AIMD to minimize a cost utility function of interest in the framework of smart grids. We then implement the AIMD utility optimisation strategies in a realistic power network simulation in Matlab-OpenDSS environment, and we show that the performance is very close to the full-communication centralized case.

Governments are promoting energy community (EC) policies to encourage joint investment and the operation of shared energy assets by citizens, industries, and public authorities, with the aim of promoting economic, social, and environmental benefits. However, ECs require appropriate planning and energy management strategies, which require data that are rarely clean and well-structured. Data providers rarely adhere to a common format for data sharing, which hinders the development of ECs. As the number of ECs is expected to grow significantly, this poses significant issues for stakeholders to quickly and efficiently develop projects. To address this issue, in this paper we propose a literature-based analysis and classification to derive the major data needs for EC planning, as well as a template format for data sharing. Our literature review on ECs successfully identifies the main data required to properly describe this system and its components. Their classification further clarifies that data structures shall account for tabular-like data of various types and flexible dimentionality, or cardinality. A public release of an open dataset for a case study in Pisa, Italy is also provided, supported by realistic or real data for testing the sizing and operation of ECs. The results suggest that data standard practices are needed, and this paper can lay the foundation for their standardization for ECs to fast-forward their deployment as support policy and technical decision-making.

Energy Communities (ECs) have been introduced as a solution to address energy system development from a multidisciplinary perspective, with energy-related, environmental, and social targets as main pillars. While some countries still struggle with implementing basic rules for ECs, others, such as Austria, already go one step further and address the topic of allowing to participate in multiple ECs at the same time. The scientific literature to date lacks of studies that investigate whether it is profitable for a new participant to join multiple ECs instead of joining only one, and, which effect this would have on the existing ECs. Thus, this paper introduces a mathematical framework to optimally allocate a new participant within an existing set of ECs. The proposed economic-based decision making problem is formulated as a Mixed Integer Linear Programming (MILP) problem. While the model determines the economically optimal solution for a new participant, it is ensured that the initial situation of the existing ECs does not worsen. Results are provided for a set of ECs with different availability of resources and located in different settlement patterns, applying current Austrian legislation. Result shows that having multiple possibilities to share energy surplus and to satisfy energy demand can result in additional revenues of 6%, making multiple participation a valuable option to be considered by policy makers.

This paper compares the impact of microgrids on the transient response of the transmission system, and, more specifically, on its frequency variations, when different control strategies and different storage capacities are employed. Extensive Monte Carlo simulations are performed based on the IEEE 39-bus system, and show that the dynamic behavior of the transmission system is affected in a non-trivial way by the control strategy of the microgrids energy management system and their storage capacity.

In this paper, the authors introduce a semianalytical model for the analysis and the design of a permanent magnet (PM) tubular linear generator intended for electrical energy generation from sea waves. The translator of the analyzed machine is constituted by axially magnetized ferrite PMs with alternating polarity and soft magnetic pole pieces in between; a two-pole, double-layer, three-phase winding is located in the slots of the stator. The presented model, based on the use of the Carter coefficient and of the Fourier transform in the direction of the motion, is able to take into account the end effects due to the finite length of the stator. The presence of slots and teeth is subsequently considered by some postprocessing calculation carried on the results of the semianalytical model. Comparison with a finite element analysis and measurements taken on a prototype has been performed to validate the presented model. The model can be easily extended to other translator typologies, e.g., to air core translator with Halbach array of NdFeB PMs.

The main objective of this paper is to illustrate the current state of the art of the newborn smart gas grid concept. We provide a detailed discussion of the envisaged features of the smart gas grid, giving attention to both the related academic literature and to the ongoing world-wide projects. In doing so, we also discuss the potentialities of rethinking the smart grid paradigm from the perspective of a whole energy system, that both encompasses the electrical and the gas grid, and identify some critical key aspects that must be handled while developing the new smart energy paradigm.

In this paper we used clustering algorithms to compare the typical load profiles of different European countries in different day of the weeks. We find out that better results are obtained if the clustering is not performed directly on the data, but on some features extracted from the data. Clustering results can be exploited by energy providers to tailor more attractive time-varying tariffs for their customers. In particular, despite the relevant differences among the several compared countries, we obtained the interesting result of indentifying a single feature that is able to distinguish weekdays from holidays and pre-holidays in all the examined countries.

In this paper the possibility to approximate the frequency response of a three-conductor power cable as a PLC channel by a two-conductor equivalent is investigated. The approximation is useful to perform faster numerical simulations of a PLC channel in the analysis or design of a three-phase PLC channel. The radius and distance between two conductors considered into a homogeneous medium are varied in a statistical way to reproduce the actual three phase PLC channel. In the numerical simulations, nine commercial power cables used in ships are considered, so that the results can be very helpful for users interested in a practical scenario. The results show that the two-conductor approximation can be obtained and it is particularly useful for the power cables of larger cross-section.