• Energy Research

This paper proposes a study about the feasibility to modulate the indoor artificial lighting, taking into account both achievable energy savings and comfort conditions, in order to reduce lighting electric loads. In particular, it focuses on the possibility, on one hand, to decrease the luminous flux and, on the other hand, to change the Correlated Colour Temperature (CCT), in order to decrease the absorbed power. Moreover, the impact of daylight-linked control systems was considered. Finally, the possibility to combine the different technical solutions was analysed. The paper proposes the definition of daily scheduling referred to lighting energy management, in order to modulate the maximum load value, maintaining a minimum during the rest of the time for an office end use.

In this paper, the implementation of a simulation model for studying the effect of cross-bonding of metallic sheaths and/or non-magnetic armor of single-core medium voltage cables in the same circuit is discussed. With the use of single-core cables, the resistive losses due to the induced circulating currents in cable sheaths or armors causes an increase of cable temperature that reduces its ampacity. In addition, the risk of electric shock due to induced voltages may be present if a person is exposed to the armor/sheath at the unbounded end. For this reason, special bonding techniques are used to significantly reduce these currents. The authors have implemented a model that could be used to help optimize the cross-bonding configuration for single-core cables employed in high-current industrial applications. The model has been experimentally validated thanks to actual data from a medium-voltage underground line.

Time-of-use energy cost management involves the use of storage by customers to reduce their electricity bills. This can be accomplished by charging the storage during off-peak time periods, when electricity energy prices are low, and discharging it during times when on-peak energy prices are applied. This article addresses the question whether it is economically viable to install medium-scale distributed storage devices in the power system designed to lower the electricity cost for a customer-side application, assuming flexible electricity tariffs. The technical/economical evaluation is carried out referring to Lithium ion (Li-ion), Sodium Sulphur (NaS) and Vanadium Redox Battery (VRB) technologies, performing a parametric analysis by changing the capital cost of the batteries and the difference between the maximum and minimum electricity price. A case study is performed to show the advantages/disadvantages of the proposed approach.

Abstract Building automation systems are able to influence significantly buildings’ energy performance. The BAC factors method, presented for the first time by the International Standard EN 15232, is the most used and simple instrument for evaluating the impact of such systems in terms of reduction of the electrical and thermal energy consumption of buildings services. Nevertheless, Standard EN 15232 does not take into consideration the automation of lighting systems serving buildings’ external areas like passages, gardens, entrance walkways, etc. In some cases, such areas can be very extended and, as a consequence, responsible for a not negligible percentage of the overall electricity consumption. Taking this last consideration as a basis, in this paper, a method is proposed for the definition and the evaluation of a new BAC factor for outdoor lighting systems, named OL-BAC factor. The method can be considered complementary to the one proposed by the Standard EN 15232 for the indoor lighting energy consumption estimation and proposes some improvements in the implementation of the latter. In particular, in this paper, the OL-BAC factors are calculated showing the importance of two parameters that are not taken into account by the Standard EN 15232: the latitude of the installation site and the energy absorbed by the devices for the luminaires’ automatic control.

The paper presents a study carried out on the island of Pantelleria regarding the interaction among distributed energy resource and energy storage systems in renewable energy communities. EU, in the Clean Energy Package, defines the 'Jointly acting renewables self-consumers' (JARSCs) and the 'Renewable Energy Communities' (RECs) as innovative models to share energy from renewables facilities. Nevertheless, the behaviour of JARSCs and RECs is designed to maximize the final users' self-consumption without considering the impacts on the power grid operation. A comparison of various operational strategies of BESS and an investigation of their effect on the distribution network are key elements for the evolution and development of JACSRs and RECs in small islands. In the following, a model is proposed to size a PV plant and a battery storage system in an energy community and to analyse the economic impact of the management of the battery, considering the Italyn regulatory framework for RECs and the peculiar conditions of the power system of Pantelleria. The Energy Community model consists of a set of electrical loads, some controllable and some not, a photovoltaic generator representing the set of generators installed at the Energy Community users and a storage system representing the set of Battery Energy Storage System of the Energy Community members.

The paper deals with the new course of the Feed-in Tariffs mechanism for photovoltaic systems that will start from January 1, 2011 in Italy with the actuation of the Government Decree DM 06/08/2010. After a short introduction on Feed-in Tariffs and Net-metering in Italy, the paper focuses the attention on an economical comparison between the incentives established by the Government Decree DM 19/02/07, ended on December 31, 2010 and those introduced by the DM 06/08/2010. The economical comparison is based on three indexes: the Pay Back Period, the Net Present Value and the Internal Rate of Return, characterizing the investments done for the realization of the photovoltaic systems. In particular, simulations show how the new Decree significantly penalizes the architectural integration, that represents a strongly criticism of the new incentive policy.

The work presents the results of a study regarding the impact of Demand Side Management actions on flexible loads distributed at the domestic end-users’ facilities in an isolated low voltage microgrid. Aim of the research study is to evaluate how the implementation of local control actions on the end-user’s side can impact on the operation of the isolated microgrid. The Demand Side Management is applied by each domestic user to optimize the operation of its own resources following well-defined operative steps. The study is carried out implementing a suitable model of the microgrid in Neplan environment, while the daily controlled load profiles of the end-users are evaluated using the Montecarlo approach implemented in Matlab. The results of the study are useful to the DSOs which will face all the issues rising in a fully-automated environment.