• Energy Research

Abstract Increasing electrification of final uses can be a viable solution towards low-carbon energy systems, when coupled with local renewable power generation. Mountain areas can already benefit from high shares of hydro-power generation, but, at the same time, rely on oil products for transport and for the heating sector in remote areas where natural gas infrastructures are not available. This research work evaluates potential scenarios for the electrification of transport and heating sectors, by coupling the simulation tool EnergyPLAN with a multi-objective optimization algorithm to analyse economic and environmental aspects. Results show that the largest benefits are expected from the electrification of the heating sector. Indeed, a CO2 emissions reduction up to 30% can be reached by acting on the transport sector alone, while up to 65% combining it with measures on heating, industry and agriculture sectors and additional electricity generation from photovoltaic systems. Moreover, the use of heat pumps can lead to significant CO2 emissions decrease with only to a slight increase in the overall annual costs thanks to lower variable costs that partly compensate the higher required initial investment and electricity storage deployment. The optimization analyses also highlight the effect of progressive penetration of electric vehicles in the private cars fleet and hydrogen trucks in the light-duty vehicles one.

AbstractSEAKERS (SEA Kinetic Energy Recovery System) is a research project, funded within the 7th EU Framework Program, whose goal is to develop an innovative device consisting in a model of a kinetic energy recovery system for sailing yachts, based on the conversion of wave-induced boat oscillations (heave, pitch and roll) into electric energy by means of a linear generator. The device aims at recovering as much kinetic energy as possible from the natural movements of a sailing yacht on the sea, therefore taking the view of a boat as a moving wave energy converter with energy harvesting capability. The boat's motions can be vertical oscillations due to the buoyancy in the presence of sea waves and rolling and pitching motions originated both by sailing in wavy waters and by the normal boat dynamics due to the sails’ propulsion. This paper presents a brief description of the prototype of linear generator, which has been developed in the SEAKERS project, and reports about the first experimental tests carried out on the prototype. Two kind of tests have been performed on the generator, which can be classified as a linear permanent magnet switched reluctance generator: first, the possibility to use the prototype like an actuator has been investigated, in order to force the cursor to have a motion in phase with the external forcing, so as to recover more energy when the machine acts as generator. The behaviour of the actuator was examined in a static way, measuring the forces between cursor and stator, varying relative position of cursor and current in the coils. The second kind of tests has been performed to analyse the efficiency of the generator, for different external loads and translational velocities. The trend shown in these tests are then explained by an analytical model based on an electromagnetic circuit.

In January 2011, the introduction of high-efficiency cogeneration in Europe radically modified the incentive scheme for combined heat and power (CHP) plants. Since then, the techno-economic feasibility of new cogeneration plants in different areas of application (industry, service, residential, etc.), along with the definition of their optimal operation, have inevitably undergone a radical change. In particular, with reference to the Italian case and according to the most recent ministerial guidelines following the new EU regulation, in the event that cogeneration power plants do not reach an established value in terms of overall efficiency, their operation has to be split into a CHP and a non-CHP portion with incentives proportional to the energy quantities pertaining to the CHP portion only. In the framework of high-efficiency cogeneration, the present study compares different CHP solutions to be coupled with the paper industry that, among all the industrial processes, appears to be the best suited for cogeneration applications. With reference to this particular industrial reality, energy, environmental, and economic performance parameters have been defined, analysed, and compared with the help of GateCycle software. Among the proposed CHP alternatives, results show that gas turbines are the most appropriate technology for paper industry processes.

Electric vehicles, being able to reduce pollutant and greenhouse gas emissions and shift the economy away from oil products, can play a major role in the transition towards low-carbon energy systems. However, the related increase in electricity demand inevitably affects the strategic planning of the overall energy system as well as the definition of the optimal power generation mix. With this respect, the impact of electric vehicles may vary significantly depending on the composition of both total primary energy supply and electricity generation. In this study, Italy and Germany are compared to highlight how a similarity in their renewable shares not necessarily leads to a CO2 emissions reduction. Different energy scenarios are simulated with the help of EnergyPLAN software assuming a progressive increase in renewable energy sources capacity and electric vehicles penetration. Results show that, for the German case, the additional electricity required leads to a reduction in CO2 emissions only if renewable capacity increases significantly, whereas the Italian energy system benefits from transport electrification even at low renewable capacity. Smart charging strategies are also found to foster renewable integration; however, power curtailments are still significant at high renewable capacity in the absence of large-scale energy storage systems.

Increasing electrification of final uses can be a viable solution towards low-carbon energy systems, when coupled with local renewable power generation. Mountain areas can already benefit from high shares of hydro-power generation, but, at the same time, rely on oil products for transport and for the heating sector in remote areas where natural gas infrastructures are not available. This research work evaluates potential scenarios for the electrification of transport and heating sectors, by coupling the simulation tool EnergyPLAN with a multi-objective optimization algorithm to analyse economic and environmental aspects. Results show that the largest benefits are expected from the electrification of the heating sector. Indeed, a CO2 emissions reduction up to 30% can be reached by acting on the transport sector alone, while up to 65% combining it with measures on heating, industry and agriculture sectors and additional electricity generation from photovoltaic systems. Moreover, the use of heat pumps can lead to significant CO2 emissions decrease with only to a slight increase in the overall annual costs thanks to lower variable costs that partly compensate the higher required initial investment and electricity storage deployment. The optimization analyses also highlight the effect of progressive penetration of electric vehicles in the private cars fleet and hydrogen trucks in the light-duty vehicles one.

Abstract Integration of renewable energy in the electricity market poses significant challenges on power grid management due to the volatility of these sources. In fact, the mismatch between renewable power generation and load curves, along with the need for grid stability, may lead to substantial curtailments when potential electricity supply exceeds demand. In this respect, the surplus from renewable energies can be conveniently exploited to produce hydrogen via electrolysis. This concept can be referred to as “Power-to-Gas” and “Power-to-Liquid” when synthetic grid gas and liquid fuels are respectively produced via syngas hydrogenation processes and is rapidly emerging as a promising measure in support of renewable energy penetration, leading to the decarbonisation of energy generation without affecting grid reliability. This study evaluates the impact of Power-to-Gas and Power-to-Liquid systems on future CO2-reduced scenarios, characterised by increasing shares of renewable energies and electric vehicles under a holistic Smart Energy System perspective. Results show potential synergies among crucial energy sectors in terms of CO2 emissions, curtailments and costs. Among the proposed options, synthetic grid gas produced by biomass gasification, and subsequent hydrogenation, leads to the best techno-economic scenario with a reduction of CO2 emission of 30% with negligible change in yearly total costs.