A Schematic Framework to Assess Mini Hydro Potentials in the Italian Regional Energy and Environmental Plans

In compliance with EU legislation (Directive 2009/28/EC, that establishes for each Member State a target calculated according to the share of energy from renewable sources in its gross final consumption to 2020) and Italian regulatory framework (DM 15/03/12- Burden Sharing, that defines the regional objectives regarding renewable sources), each Italian Region must develop its own Regional Energy and Environmental Plan (PEAR). In order to promote the renewable energy sources (RES) production and to achieve a better energy efficiency use, the PEARS should propose to adopt a distributed multi generation (DMG) strategy. The main aim of this paper is a preliminary assessment of mini hydro potential and perspectives (P <1 MW) in Italian PEARS. Mini hydro is a mature and developed technology in Italy, and it represents a valiant opportunity for both local territories and the whole national system. Furthermore, thanks to its small size (low economic investment and environmental impact) and its versatility, it has the characteristics for a long-term development with direct industrial implications (i.e. energy cooperative and short supply chain). Specifically, the PEARS of four Regions were analysed, identifying the different information about mini hydro and comparing characteristics and potential. The results obtained are summarized in a schematic framework useful to draw a preliminary PEARS guideline that indicates strategies and policies, harmonizing public and private initiatives and structuring a local-scale economy through a mini hydro based DMG

Energy use in residential buildings: Impact of building automation control systems on energy performance and flexibility

This work shows the results of a research activity aimed at characterizing the energy habits of Italian residential users. In detail, by the energy simulation of a buildings sample, the opportunity to implement a demand/response program (DR) has been investigated. Italian residential utilities are poorly electrified and flexible loads are low. The presence of an automation system is an essential requirement for participating in a DR program and, in addition, it can allow important reductions in energy consumption. In this work the characteristics of three control systems have been defined, based on the services incidence on energy consumptions along with a sensitivity analysis on some energy drivers. Using the procedure established by the European Standard EN 15232, the achievable energy and economic savings have been evaluated. Finally, a financial analysis of the investments has been carried out, considering also the incentives provided by the Italian regulations. The payback time is generally not very long: depending on the control system features it varies from 7 to 10 years; moreover, the automation system installation within dwellings is a relatively simple activity, which is characterized by a limited execution times and by an initial expenditure ranging in 1000 € to 4000 €, related to the three sample systems

A GIS-based model to assess electric energy consumptions and usable renewable energy potential in Lazio region at municipality scale

The ongoing energy transition processes need a rapprochement between the places of energy production and consumption with the aim of creating innovative and integrated territorial models. Consequentially, models and strategies for increasing the use of local and renewable energy sources (RES) play a key rule for enhancing energy independence and sustainability of the considered areas. The main objective of this study is to analyse the energy system of the Lazio Region in Italy, comparing electricity consumptions and production from renewable sources at municipality scale. In order to estimate the electricity consumptions and the local production by RES, the main sectors of electricity consumption together with the potential of the available RES for the electricity production have been analysed. The obtained results pinpointed the main critical aspects of the Lazio region, that are mainly focalized in the city of Rome and in the most densely inhabited municipalities. Furthermore, research outputs provide an overall framework on the regional RES potential and allowed the formulation of proposals aimed at overcoming the identified criticalities and increasing the share of electricity production from renewables. Finally, the research approach could be replicated in other areas, providing a useful process for decision makers and stakeholders

An overview on safety issues related to hydrogen and methane blend applications in domestic and industrial use

The share of electrical energy hailing from renewable sources in the European electricity mix is increasing. The match between renewable power supply and demand has become the greatest challenge to cope with. Gas infrastructure can accommodate large volumes of electricity converted into gas whenever this supply of renewable power is larger than the grid capacity or than the electricity demand. The Power-to-Gas (P2G) process chain could play a significant role in the future energy system. Renewable electric energy can be transformed into storable hydrogen via electrolysis and subsequent methanation. The aim of this paper is to provide an overview of the required technical adaptations of the most common devices for end users such as heating plants, CHP systems, home gas furnaces and cooking surfaces, wherever these are fuelled with methane and hydrogen blends in variable percentages by volume. Special attention will be given to issues related to essential safety standards, firstly comparing existing Italian and European regulations in this regard, and secondly highlighting the potential need for legislation to regulate the suitability of hydrogen methane blends. Finally, a list of foreseeable technical solutions will be provided and discussed thoroughly

Prestazioni energetiche degli edifici: le norme UNI TS 11300-3/4

In attuazione della direttiva 2009/28/CE, sulla promozione dell’uso dell’energia da fonte rinnovabile, è stato emanato il Decreto Legislativo n.28 del 3/3/2011. Il decreto fornisce interessanti novità riguardanti i nuovi edifici o gli edifici sottoposti a ristrutturazioni rilevanti, con l’obiettivo di limitare i consumi di energia primaria dell’edificio attraverso sistemi edificio-impianti efficienti ed impiegando fonti rinnovabili di energia. Le prescrizioni contenute devono intendersi come requisito minimo, su tutto il territorio nazionale, con la conseguenza che tutti gli atti normativi regionali o comunali devono essere adeguati entro 180 giorni a quanto indicato. Per la prima volta, tra gli usi energetici dell’edificio, in termini di energia primaria, è inclusa la climatizzazione estiva, che dovrà essere in parte soddisfatta tramite il ricorso a fonti rinnovabili di energia. La norma UNI TS 11300-3 specifica le modalità di calcolo del fabbisogno di energia primaria e dei rendimenti per la stagione estiva; l’applicazione di tale norma sarà di seguito illustrata con riferimento a casi specifici, evidenziandone i punti salienti ed alcune criticità. Il decreto, inoltre, stabilisce che “energia da fonti rinnovabili” è l’energia proveniente da fonti rinnovabili non fossili, vale a dire energia eolica, solare, aerotermica, geotermica, idrotermica e oceanica, idraulica, biomassa, gas di discarica, gas dai processi di depurazione e biogas. La norma UNI TS 11300-4 riguarda l’utilizzo di energie rinnovabili e di altri metodi di generazione per riscaldamento di ambienti e preparazione acqua calda sanitaria; tale norma sarà nel seguito illustrata con riferimento alle parti ritenute più interessanti. Altra novità del decreto è il ruolo del teleriscaldamento, equiparato alle fonti rinnovabili, nel momento in cui consente il pieno soddisfacimento dei fabbisogni per riscaldamento ed acqua calda sanitaria. Il calcolo per il teleriscaldamento può essere effettuato mediante la UNI TS 11300-4

Single Cylinder Internal Combustion Engine Fuelled with H2NG Operating as Micro-CHP for Residential Use: Preliminary Experimental Analysis on Energy Performances and Numerical Simulations for LCOE Assessment

The paper presents data resulting by the preliminary experimental campaign performed on a micro CHP (combined heat and power) pre-commercial version (5 kWel) designed for dwellings. The engine employs the lubricant oil as the jacket coolant to simplify the heat recovery architecture and it was equipped by a condensing heat exchanger as well. The tests have been carried out at rated and partial load up to 2.9 kWel (59% of rated load) in condensing mode, fuelling the NG engine with hydrogen percentages equal to 0% vol. and 15% vol. In order to evaluate the CHP energy performance, the analysis was conducted for 160 h, using an alkaline electrolyser for hydrogen production, a static heat meter and two mass flow meters for both hydrogen and NG. The aim of this paper is to illustrate how the use of the hydrogen enrichment in a micro CHP plant, based on ICE technology, represents a foreseeable bridge solution to the forthcoming SOFC deployment

RES (Renewable Energy Sources) Availability Assessments for Eco-fuels Production at Local Scale: Carbon Avoidance Costs Associated to a Hybrid Biomass/H2NG-based Energy Scenario

Eco-fuels are a sustainable solution to face increasing global energy consumptions and GHG emissions. This work was firstly focused on available renewables assessment linked to a local dimension. Furthermore, identifying the potential Eco-fuels capability, it was discussed how the capital expenditure for infrastructures is associated with carbon avoidance costs. A coastal municipality and an inland one, located in Central Italy, are selected as case studies. In order to assess PV and agro-forestry residues availability, a GIS-based analysis was performed. In this framework, a new energy scenario, based on H2NG blends use and ligneous biomass conversion, was presented. Specifically, the hydrogen for NG enrichment was produced by renewable electricity, while biomass energy content was evaluated considering gasification process. Finally, the governmental incentive schemes incidence (in force for bioenergy and hypothesized for hydrogen) on investments economic sustainability and on infrastructure deployment was compared in terms of carbon avoidance costs

Dynamic simulation model of trans-critical carbon dioxide heat pump application for boosting low temperature distribution networks in dwellings

This research investigates the role of new hybrid energy system applications for developing a new plant refurbishment strategy to deploy small scale smart energy systems. This work deals with a dynamic simulation of trans-critical carbon dioxide heat pump application for boosting low temperature distribution networks to share heat for dwellings. Heat pumps provide high temperature heat to use the traditional emission systems. The new plant layout consists of an air source heat pump, four trans-critical carbon dioxide heat pumps (CO2-HPs), photovoltaic arrays, and a combined heat and power (CHP) for both domestic hot water production and electricity to partially drive the heat pumps. Furthermore, electric storage devices adoption has been evaluated. That layout has been compared to the traditional one based on separated generation systems using several energy performance indicators. Additionally, a sensitivity analysis on the primary energy saving, primary fossil energy consumptions, renewable energy fraction and renewable heat, with changes in building power to heat ratios, has been carried out. Obtained results highlighted that using the hybrid system with storage device it is possible to get a saving of 50% approximately. Consequently, CO2-HPs and hybrid systems adoption could be a viable option to achieve Near Zero Energy Building (NZEB) qualification

Cogenerazione integrata in un sistema ibrido con motore ad idrometano per un impianto natatorio

L’oggetto del presente studio è un impianto di cogenerazione alimentato ad idrometano asservito alla gestione termica di una piscina costruita all’interno del centro sportivo universitario di Tor di Quinto. Il laboratorio di sperimentazione connesso alla realizzazione di tale impianto ha come obiettivi la promozione di sistemi innovativi per la gestione energetica ed economica dell’Ateneo e la sostenibilità ambientale all’interno di una grande città come Roma. Di fatto, tale laboratorio si configura come uno dei nuovi centri di autoproduzione facente capo alla smart grid della Sapienza costituendo il primo sistema ibrido realizzato in Italia che impiega, in modo sinergico e razionale, le tecnologie della cogenerazione, del fotovoltaico e della produzione di idrogeno a bassa pressione ( 15 bar ) mediante processo elettrolitico. A partire dai risultati ottenuti da uno studio di fattibilità sulla piscina si è determinata la taglia di 60 kW elettrici per il cogeneratore. Per l’ alimentazione del motore a combustione interna è stata prevista la possibilità di operare con gas metano al 100 %, oppure con una miscela arricchita di idrogeno di composizione modulabile ( nel range 0 - 10 % in volume ) mediante interposizione di un buffer di disaccoppiamento (capacità: 60 litri) ed apposita apparecchiatura miscelatrice. L’idrogeno viene prodotto da un elettrolizzatore alcalino (potenzialità: 1.1 Nm3/h ) che assorbe una potenza elettrica di 5.5 kW in parte dalla rete e in parte da un impianto fotovoltaico (6 kW) grid - connected totalmente integrato in facciata di una palazzina adiacente. Con il completamento dell’installazione del sistema di analisi fumi in continuo sarà possibile effettuare i test sul motore e valutare le prestazioni energetiche ed ambientali dell’intero sistema ibrid

Smart energy systems for renewable energy communities. A comparative analysis of power-to-X strategies for improving energy self-consumption

Renewable energy communities (RECs) represent the new scheme for promoting the distributed renewable generation, which must be managed to maximise the local energy self-consumption. The aim of this paper is to assess and discuss strengths and weaknesses of small-scale sector coupling strategies in residential RECs by means of a comparative analysis of their applications. Different power-to-X strategies have been applied to twenty-seven REC configurations. The systems have been separately simulated by means of the EnergyPLAN software. Power to-heat strategy turns out to be the most cost-effective solution to integrate the RES excess, however, its potential often is not enough to fully accommodate it. Power-to-vehicle has low infrastructure costs, but its limit depends on the electric vehicle penetration and citizens' participation. Exploiting the electric vehicle batteries is always more cost-effective than installing stationary batteries. The competitiveness of power-to-power is extremely linked to the REC electrification level. Power-to-gas is promising in high-RES excess conditions, but rarely represents the best solution due to current high electrolyser costs. The implementation of energy storage systems is crucial for improving the local self-consumption and the cross-sector integration is a better solution in energy, economic and environmental terms than focusing only on the electricity sector