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In Europe, the recast of Directive 2018/2001 defined Renewable Energy Communities as innovative configurations for renewable energy sharing between different end user types. In this regard, this work aims to assess the benefits following the constitution of a Renewable Energy Community in the industrial area of Benevento (South of Italy), involving a mixed-use building and an industrial wastewater treatment plant. The alternative single end users' configuration has been also examined, and both solutions have been compared with the current state where the users' electric energy requests are fully met by the power grid. The users have been equipped with a 466 kWp photovoltaic plant, modelled in HOMER Pro®, providing in input experimental meteorological data (global solar radiation and air temperature) collected by one of the weather control units in Benevento. Real data about users' electric energy demand have been gathered from their electricity bills, and when unavailable their electric load profiles on an hourly basis have been reconstructed based on the aggregated monthly data. Energy sharing has been proven to increase energy self-consumption and the users' self-sufficiency. Annually, the primary energy demand is reduced by 577 MWh (1.2 MWh/kWp), carbon dioxide emissions by 84 tCO2 and operative costs by 101 kEUR. [ABSTRACT FROM AUTHOR]

The use of macro storage technologies has been widely studied in the literature with pumped hydro energy storage (PHES) emerging as the main option for its high stability and low environmental impact. Additionally, in recent years researchers have focused on combining a micro storage system with a photovoltaic and/or wind system that serves to increase self-consumption thereby reducing the load on the power grid. However, the selection of optimal micro system remains an open issue. This study thus proposes a methodology for selecting the optimal PHES system based on energy and economic analyses. The methodology was validated through a case study involving university buildings (University of Sannio) in Benevento - Italy, in which a photovoltaic system with peak power of about 142 kW was considered. The results obtained through a sensitivity analysis varying the total volume of reservoirs, showed an effective reduction in energy purchased from and sold to the grid. Subsequently the use of PHES system was compared with battery-based storage, commonly installed in building application. The energy produced from renewable sources delivered to the building increased by 25 % and 13 % for battery energy storage system (BESS) and PHES system, respectively. The economic analysis demonstrated the BESS to be most cost effective with a minimum levelized cost of storage of about 158 €/MWh, while the pumped hydro energy system showed attractive economic results only when the investment costs exclude the reservoirs (levelized cost of storage was 136.5 €/MWh). [ABSTRACT FROM AUTHOR]

Tobacco is traditionally used for cigarettes and cigars manufacturing and after the drying process a great quantity of dry tobacco stalks is treated as waste. In this framework, the scope of the paper is to examine the use of tobacco stems to feed a biomass boiler after a chipping process. The study is focused on southern Italy area thus, firstly, the assessment of tobacco availability in Italy and Campania region has been determined. Then, Burley tobacco stalks sampled out in an air-curing factory of south Italy crop have been characterized according to ASTM D5142 and ASTM D5373 standards. Thereby, biomass and natural gas fuelled boilers have been compared through an energy, environmental and economic analysis on simulative basis. Both systems satisfy the thermal energy demands of a multi-purpose condominium located in a cold Italian climatic zone near the factory. The results have demonstrated that boiler fed by tobacco chips ensures environmental and economic advantages compared to traditional system. In particular, it guarantees a reduction of CO 2 emissions up to 16.59 tCO 2 in one of investigated scenarios and a simple payback period and a net present value of about 5.6 years and 17,168 € (without economic support), respectively. • Tobacco stalks availability in Italy and Campania region is assessed. • Tobacco stems proximate and ultimate analyses show results similar to woody biomasses. • Boiler fed by tobacco chips and natural gas fuelled one are modelled and simulated. • A techno-economic and environmental performance comparison is implemented. • The energy, environmental and economic results reward plant fed tobacco by chips. [ABSTRACT FROM AUTHOR]

The highest economic costs of a geothermal plant are basically related to well drilling and heat exchanger maintenance cost due to the chemical aggressiveness of geothermal fluid. The possibility to reduce these costs represents an opportunity to push toward geothermal plants development. Such challenges are even more important in the sites with a low-medium temperature geothermal fluids (90–120 °C) availability, where the use of these fluids for direct thermal uses can be very advantageous. For this reason, in this study, a direct geothermal heating system for a building will be investigated by considering a plastic plate heat exchanger. The choice of a polymeric heat exchanger for this application is upheld by its lower purchase cost and its higher fouling resistance than the common metal heat exchangers, overcoming the economic issues related to conventional geothermal plant. Thus, the plastic plate heat exchanger was, firstly, geometrical and thermodynamical modeled and, after, exergoeconomic optimized. In particular, an exergoeconomic analysis was assessed on the heat exchanger system by using a MATLAB and REFPROP environment, that allows for determination of the exergoeconomic costs of the geothermal fluid extraction, the heat exchanger, and the heating production. A sensitivity analysis was performed to evaluate the effect of main design variable (number of plates/channels) and thermodynamic variable (inlet temperature of geothermal fluid) on yearly exergoeconomic product cost. Then, the proposed methodology was applied to a case study in South of Italy, where a low-medium enthalpy geothermal potential exists. The plate-heat exchanger was used to meet the space heating requests of a single building by the exploitation of low-medium temperature geothermal fluids availability in the selected area. The results show that the inlet temperature of geothermal fluid influences the exergoeconomic cost more than the geometrical parameter. The variation of the exergoeconomic cost of heat exchanger with the inlet geothermal fluid temperature is higher than the change of the exergoeconomic costs associated to wells drilling and pumping with respect to the same variable. This is due the fact that, in the selected zone of South of Italy, it is possible to find geothermal fluid in the temperature range of 90–120 °C, at shallow depth. The product exergoeconomic cost is the lowest when the temperature is higher than 105 °C; thus, the smallest heat exchange area is required. The exergoeconomic optimization determines an optimum solution with a total product cost of 922 €/y for a temperature of geothermal fluid equal to 117 °C and with a number of plates equal to 15. [ABSTRACT FROM AUTHOR]

This paper presents a thermodynamic, economic, and environmental analysis of a renewable polygeneration system connected to a district heating and cooling network. The system, fed by geothermal energy, provides thermal energy for heating and cooling, and domestic hot water for a residential district located in the metropolitan city of Naples (South of Italy). The produced electricity is partly used for auxiliaries of the thermal district and partly sold to the power grid. A calibration control strategy was implemented by considering manufacturer data matching the appropriate operating temperature levels in each component. The cooling and thermal demands of the connected users were calculated using suitable building dynamic simulation models. An energy network dedicated to heating and cooling loads was designed and simulated by considering the variable ground temperature throughout the year, as well as the accurate heat transfer coefficients and pressure losses of the network pipes. The results were based on a 1-year dynamic simulation and were analyzed on a daily, monthly, and yearly basis. The performance was evaluated by means of the main economic and environmental aspects. Two parametric analyses were performed by varying geothermal well depth, to consider the uncertainty in the geofluid temperature as a function of the depth, and by varying the time of operation of the district heating and cooling network. Additionally, the economic analysis was performed by considering two different scenarios with and without feed-in tariffs. Based on the assumptions made, the system is economically feasible only if feed-in tariffs are considered: the minimum Simple Pay Back period is 7.00 years, corresponding to a Discounted Pay Back period of 8.84 years, and the maximum Net Present Value is 6.11 M€, corresponding to a Profit Index of 77.9% and a maximum Internal Rate of Return of 13.0%. The system allows avoiding exploitation of 27.2 GWh of primary energy yearly, corresponding to 5.49∙103 tons of CO2 avoided emissions. The increase of the time of the operation increases the economic profitability. [ABSTRACT FROM AUTHOR]