• Energy Research

Public lighting system represents a key role in the energy transition process, considering the high electricity consumptions related to this sector. The integration of renewables could be suitable for this application and many solutions of solar-based lamps for street lighting are spreading. In this research work, a specific application of a PV-integrated lighting system was installed in the center of Italy along a footpath and monitored for several months, both in terms of electricity parameters and lighting behavior. It is equipped with monocrystalline photovoltaic cells, a lithium-based battery, and a LED lamp. The measured data allow the development of an optimization algorithm in Python program for the correct management of the solar streetlamp and the forecasting of electricity consumptions for different boundary conditions (e.g. Italian geographical position). The energy taken from grid in a year is very low with respect to a traditional lamp not powered by renewables: only 43-46% in central-northern regions and 35% in south region. Data are also used to study the possible substitution of all the traditional lamppost of the walkway with the novel proposed system. A technical-economic analysis is carried out to analyze the effectiveness of this solution not only in terms of electricity consumptions reduction, but also costs savings. The suitability of the investment and the payback time depend on Italian national price of electricity and initial cost of the solar lamp. The results can be applied to similar case studies in Italy to save electricity consumptions and reduce CO2 emissions.

In recent years the development of LVDC distribution networks is under consideration. DC electrical distributions offer several advantages compared to AC ones in many applications, in particular in the presence of energy storage systems and distributed generation like high efficacy, flexibility and simple integration of renewables. The DC distribution allows to integrate in a more efficient “microgrid” different sources with DC/DC converters. The paper proposes an innovative model of microgrid configuration for aggregations of end-users able to share the power produced by common generators and energy services named by the authors Power Sharing Model (PSM) using a DC bus that connects in a one way approach, the common generators to the end-users. The paper investigates on the different suggested configurations of the PSM, with the converter characteristics and controls. A simplified case study is analyzed to test the performance of the sharing model and the stability of the control in different scenarios. The paper compares the PSM based on a LVDC grid with existing approaches of virtual aggregations, and it highlights the main differences between the currently existing methods and our new LVDC microgrid approach. The suggested PSM appears more efficient, convenient and flexible than the existing virtual models, because users physically self-consume and share the energy locally generated.

This study examines the electrical performance and management of hybrid solar street lighting systems with the objective of optimizing their operation for sustainable urban development. Hybrid solar streetlights, which integrate photovoltaic panels with additional power sources, offer resilience and reliability that are crucial for urban settings. A hybrid solar streetlamp was installed in a city in central Italy and monitored for over a year to analyze its electrical behavior and the illuminances obtainable under different boundary conditions and operational programs. The measured data permit the development of an optimization algorithm in a Python program for the optimal management of the solar streetlamp and the forecasting of the battery charging/discharging cycles, as well as the electricity taken from the grid. The simulation scenarios permit the development of a novel management algorithm that is capable of optimizing the battery usage with a minimal draw on the grid in order to achieve a state of near self-sufficiency for the solar streetlamp. The results demonstrate that tilted solar panels enhance energy production, while optimized LED power profiles and system management enhance efficiency. The study highlights the importance of maintaining the state of charge (SOC) of the battery above 20% to extend its lifetime and reduce replacement needs. Economic analysis indicates significant potential energy savings, emphasizing the necessity of system optimization for economic viability and environmental sustainability in urban lighting. Despite initial investment costs and challenges, adopting hybrid solar lighting in urban environments presents substantial benefits, paving the way for a more sustainable and energy-efficient urban future.

Fifteen years after the connection of the first PV plant to the distribution network of the city of Milan, the role of this technology is more and more crucial, considering the Italian and European energy transition goals. The availability of a zero-emission modular and dispersed electricity generation could allow the cities to meet the growing electricity demand in the coming years in a sustainable way. The PV plants that could be installed on the roofs of city buildings represent a precious resource, which has only been partially exploited. Quantifying this available surface can help to understand the electricity generation potential in relation to the future scenarios of electricity demand. This paper aims to analyze these aspects focusing on the city of Milan (Italy), determining the total power that could be installed on the roofs, its potential contribution to the electricity balance of the network distribution in 2020-2030 and the benefits for the grid in relation to the system losses.

In order to put into practice the objectives proposed by the policy of energy transition towards systems and buildings increasingly electrified, smart and sustainable, the massive digitization of environments and systems in both residential and commercial plays a key role, in view of the 'internet of things'. This paper aims to demonstrate the possibility of creating a reliable and robust building automation and monitoring system, maintaining, at the same time, a character of cost-effectiveness essential for a massive spread of these technologies. A case study has been realized by taking as reference a typical home in which smart devices have been placed, aimed at equipment controlling and widespread energy consumption monitoring, both electrical and thermal. Also the main environmental parameters influencing energy processes are monitored, such as: position of the windows (open/closed), temperature and humidity of the individual areas air, levels of illuminance and the presence of people in the rooms and in the entire building. These elements were then integrated into the open source SCADA (or better personal hub) 'Home Assistant' and made available on a very simple dashboard, locally accessible through any web browser. As we will see, the complete low-cost smartization of the house brings a considerable advantage on energy savings, as well as an obvious greater comfort for users. © 2022 IEEE.

In recent years the development of the LVDC distribution networks is under consideration. DC electrical distribution offers several advantages compared to AC in many applications, in particular in the presence of distributed generation and energy storage systems like high efficacy, flexibility and simple integrated to renewable sources. The DC distribution allows to integrate in a more efficient 'microgrid' different sources with DC/DC converters. The paper proposes an innovative model of microgrid architecture for aggregations of users able to share the power produced by common generators and energy services called power sharing model (PSM) using a DC bus, called power sharing link (PSL), that connects the common generators to the users. Each user has also an independent AC connection point with the distributor and a power electronic converter as Open Unified Power Quality Conditioner (Open UPQC), so PSM can be easily implemented in special power sharing contracts compliant with national regulatory systems. The produced energy is shared by PSL to the users through unidirectional power electronic device. In this way the common generator is like a multiple generator without power exchange between users and each user remain passive towards the distributor. Only the balance node of the DC bus assumes a role of active user.

The pandemic generated by Covid-19 caused social and economic consequences that constituted a global challenge for all countries. Italy was one of the first nations to be affected by the pandemic, especially in the heart of its production system and in the most densely populated area: the Lombardy Region. Starting in February 2020, there was a progressive slowdown until a total lockdown that paralyzed almost all social and economic activities, until a partial resumption of normal activities in May and a further increase in mid-June. The study was motivated by the fact that the electricity demand strongly decreased and changed in its typical characteristics, introducing new critical issues in the system at both the transmission and distribution levels. The goal was to analyze the strong impact of this changes on the distribution network and the transmission grid, focusing on the distribution network of Milan during the whole period. The results provide a useful example of the effects of such a pandemic and can constitute a reference valid also for many other big cities in the world.

In this study, a novel trigeneration system is conceived to produce heat and electricity and to provide cooling for the health treatments and touristic facilities of a spa, based on the natural hot water and solar sources. The power generation components, individually considered, are commercially available ones, but their novel combination and the complex power flow management represented a challenge. The proposed system is composed of a low‐temperature driven adsorption chiller, thermally activated by a low enthalpy geothermal source, and by hybrid photovoltaic/thermal panels. In this way, multiple objectives are achieved: produce electricity and thermal energy by renewable sources; optimise the use of different renewable sources (geothermal and solar); use the energy available for free from a geothermal source also during summer (otherwise wasted) to produce a cooling effect, and in so doing, avoiding the huge electricity consumption of conventional air conditioning units in summer; reduce the temperature of the fluids released to the environment (in a natural reserve); reduce the CO2 emissions by 45% with respect to the present configuration, limiting the global warming. The mathematical models were experimentally validated using a pilot plant built on purpose, and the performance of the whole system was analysed and discussed.