Optimization of energy production systems is a relevant issue that must be considered in order to follow the fossil fuels consumption reduction policies and CO₂ emission regulation. Increasing electricity production from renewable resources (e.g., photovoltaic systems and wind farms) is desirable but its unpredictability is a cause of problems for the main grid stability. A system with multiple energy sources represents an efficient solution, by realizing an interface among renewable energy sources, energy storage systems, and conventional power generators. Direct consequences of multi-energy systems are a wider energy flexibility and benefits for the electric grid, the purpose of this paper is to propose the best technology combination for electricity generation from a mix of renewable energy resources to satisfy the electrical needs. The paper identifies the optimal off-grid option and compares this with conventional grid extension, through the use of HOMER software. The solution obtained shows that a hybrid combination of renewable energy generators at an off-grid location can be a cost-effective alternative to grid extension and it is sustainable, techno-economically viable, and environmentally sound. The results show how this innovative energetic approach can provide a cost reduction in power supply and energy fees of 40% and 25%, respectively, and CO₂ emission decrease attained around 18%. Furthermore, the multi-energy system taken as the case study has been optimized through the utilization of three different type of energy storage (Pb-Ac batteries, flywheels, and micro—Compressed Air Energy Storage (C.A.E.S.).

The goal of this paper was to evaluate the energy savings achieved through the use of different building thermal automation systems by means of software TRNSYS. The reference building is sited in Milan in a street canyon and it's thermophisical caratheristics of the envelope are as current law require. The idea comes from the study of the European Standard CEN EN15232 “Energy performance of buildings - Impact of Automation, Controls and Building Management” which highlights how the inclusion in buildings (residential and tertiary) of Control Systems and Automation lead to a reduction of energy consumption. They then evaluate these reductions in function of the type of automation implemented. This evaluations are made only for heating system and for a residential building.

The purpose of this manuscript is to analyze the interventions of energy retrofit of a non-residential and historic building, through a dynamic simulation by the use of the TRNsys code. The study is made up of some steps: · the analysis of the building and utility data, including study of the installed equipment and analysis of energy bills; · the survey of the real operating conditions; · the selection and the evaluation of energy saving measures; · the identification of interventions of energy retrofit; · TRNsys simulation of the effects of these interventions on energy behavior of the building. The paper aims to show the results of the study, to discuss the expected energy behaviour of the building and to comment on the options for introducing energy saving techniques.

Schools represent a large slice of the non-residential building stock if you think that their usual users spend a lot of time time in their spaces. This paper presents a study of the energy performance in a school building in Rome. The main purpose is the determination of the energy demands according to UNI TS 11300 and the comparison of these results with those obtained by means of dynamic analyses and with the actual energy consumptions. This issue is very important not only because of the criticality of current energy situation but also because the reasons of the energy wastes are strongly related to the inefficiencies in the management of structures and technologic plants which may be widely avoided with smart and low cost interventions.