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Gargiulo A.,54 Energy | Girardi P.,54 Energy | Temporelli A.,54 Energy
International Journal of Life Cycle Assessment | Year: 2017

Purpose: The purpose of this article is to realize a review of studies dealing with life cycle assessment of electric grids or their components, in order to put in evidence methodological aspects to be considered with particular attention or requiring further deepening in future researches. After a preliminary bibliographic screening, the review analyses 16 scientific articles. Methods: The review considers 16 studies which are all based on a life cycle perspective and pays particular attention on some methodological issues such as: functional unit definition, selection of the impact categories, energy mix taken into consideration in order to quantify the environmental impact associated with grid losses, and end of life of grid components. The review considers, also, the analysed studies’ compliance to ISO 14040 recommendations. Results and discussion: All the 16 studies have a good degree of compliance with ISO 14040. Concerning impact categories selection, the review showed a wide set of impacts taken into consideration: some categories are frequently utilized while others are present only in few studies. The analysis puts in evidence that recycling is a crucial aspect, determining a sensible reduction of impacts, which in some cases can compensate for the total impact of the end-of-life stage. Energy losses have a great influence on the overall impact. Neglecting losses in the valuation of networks or resistive components may be too simplifying, if not even misleading. Selecting a suitable functional unit is not an easy task. Conclusions: Beyond the specific outcomes, the analysis puts in evidence two general research needs. First, the definition of functional unit: some authors use a very specific functional unit which allows a correct description of the service provided by an electricity network while others use a functional unit allowing easier comparison with other studies. Second, considering the loss relevance and the infrastructure lifespan, an appropriate evaluation of the electricity mix is crucial. © 2017 Springer-Verlag Berlin Heidelberg

Dehkordi S.E.,University of Western Ontario | Schincariol R.A.,University of Western Ontario | Reitsma S.,54 Energy
Renewable Energy | Year: 2015

A major attribute that affects a borehole heat exchanger's performance is its thermal resistance. Internal and borehole thermal resistances, among other factors, depend on the location of pipes in relation to each other and the borehole wall. The internal borehole resistance defines the short-circuit effect between the pipes, and the borehole thermal resistance is an indication of heat exchange ability with the ground. Effective borehole resistance depends on both abovementioned thermal resistance components, and describes the thermal efficiency of the BHE. It is found that the temperatures of the loop fluid and borehole wall respectively are sensitive to pipe separation and borehole diameter. This study confirms that proximity of the pipes to the borehole wall is more important than the pipe separation in reducing the total borehole resistance (i.e. temperature difference between loop fluid and borehole wall). Hence, a tight borehole design, with little spacing between the down-hole pipes, and the borehole wall, is proposed here. In such a design, a narrow borehole diameter is used with no pipe spacers. Through numerical modelling and thermal response testing, this study shows that a tight borehole heat exchanger could provide an acceptable thermal performance while optimizing the drilling and grouting volumes. © 2015 Elsevier Ltd.

Cristiani P.,54 Energy | Perboni G.,Centro Elettrotecnico Sperimentale Italiano
Bioelectrochemistry | Year: 2014

Biofouling and corrosion phenomena dramatically reduce the functionality of industrial cooling circuits, especially in marine environments. This study underlines the effectiveness of a low level chlorination treatment of seawater to prevent biological fouling and biocorrosion.Reported examples emphasize the reaction of chlorine with bromide, ammonia and organic compounds in seawater and the effectiveness of a treatment performed in such a way to guarantee a residual concentration lower than 3. μM at the outlet of the condensers.In a brief review of antifouling strategies, alternatives to chlorination and the monitoring approach able to optimize the treatments are also reported.An integrated, on-line system based on electrochemical probes (Biox system and a linear polarization resistance probe) demonstrated to be sufficient to monitor in real time: corrosion, biofilm growth and chemical treatments based on chlorine or alternative oxidant products (chlorine dioxide, etc.).A careful electrochemical monitoring and the optimized treatments help the plant operators of industrial cooling circuits prevent the decay of the equipment performance, allowing at the same time the control of the halogenated by-products formation. © 2014 Elsevier B.V.

Alessandrini S.,54 Energy | Ferrero E.,University of Piemonte Orientale
International Journal of Environment and Pollution | Year: 2011

In this work, a Lagrangian particle model able to account for simple chemical reactions between NO and O 3 has been improved to consider the photolysis of NO 2. A system of chemical equations is numerically solved on a Eulerian grid, while the particle trajectories are moved in a Lagrangian frame. The NO x emissions of a power plant in real atmosphere, situated in a complex topography environment, have been considered as a test case. The simulated episodes refer to the diurnal time, when the ultraviolet radiation activates the NO 2. Comparisons between NO/NO 2's concentrations ratio are presented in terms of scatter plots and statistical indexes analysis. Copyright © 2011 Inderscience Enterprises Ltd.

Cayci H.,54 Energy
Metrology and Measurement Systems | Year: 2011

A practical method with high accuracy in generation and application of error values for calibration of current transformer test sets is described. A PC-controlled three-phase power source with a standard wattmeter is used for generating the nominal and error test currents while an electronically compensated current comparator is used to provide summation and subtraction of them, precisely. With this method, any ratio error and phase displacement values could be generated automatically and nominal and test currents could be grounded on the test set safely. Because of its high accurate ratio and phase error generating capability, any type of test set regardless of its operating principles could be calibrated. © 2011 Polish Academy of Sciences.

Benini M.,54 Energy | Zani A.,54 Energy
2011 8th International Conference on the European Energy Market, EEM 11 | Year: 2011

The paper is aimed to assess the impact of a non-optimal development of the European cross-border electricity transmission network. The assessment has been carried out by developing and running a model of the European power system, by means of which we compared scenarios characterized by the developments of cross-border interconnections proposed by the different European TSOs ("proposed expansion") with the optimal (in terms of least overall cost) developments determined by the model ("optimal expansion"). The assessment, focused on security of supply (in terms of energy not supplied), competitiveness (electricity production costs) and sustainability (CO 2 emissions), showed that the "proposed expansion" is clearly sub-optimal, since in the optimal expansion case several interconnections are expanded significantly more. © 2011 IEEE.

Zani A.,54 Energy | Migliavacca G.,54 Energy
2011 8th International Conference on the European Energy Market, EEM 11 | Year: 2011

This paper describes the results of a study, carried out in the framework of the EU research project SUSPLAN and aimed at assessing how the EU Electricity Transmission Network should be upgraded so as to allow integrating the maximum share of renewable energy sources (RES) in Europe within the timeframe 2030-2050. The investigation, carried out by developing and running a model of the whole European power system, is focused on assessing optimal electricity transmission network expansions of the trans-national corridors between the European countries, so as to ensure security of electricity supply while keeping into account the impact on electricity production costs and CO 2 emissions. In particular, we compared the outcome of the four benchmark scenarios of the SUSPLAN 1 project. These scenarios are differentiated on the basis of two drivers: public acceptance and technological development. The reference years considered in the study are 2030, 2040 and 2050. In the following, the methodology, the assumptions and the results of the study will be reported. © 2011 IEEE.

Amicarelli A.,54 Energy | Agate G.,54 Energy | Guandalini R.,54 Energy
International Journal for Numerical Methods in Engineering | Year: 2013

A 3D fully Lagrangian smoothed particle hydrodynamics (SPH) model has been developed adopting a particle approximation, which considers both volume and surface elements at boundaries. The model is based on the main principles of the 2D model of Ferrand et al. (2012) and on the spatial reconstruction schemes used in SPH-arbitrary Lagrangian-Eulerian modeling to treat boundaries (Marongiu et al., 2007). This model is conceived to represent free surface flows and their interactions with solid structures. It is validated on a 2D water jet impact over a plate, a sloshing tank test case, and two experimental 3D dam break fronts, which interact with fixed obstacles. The results are compared with the available measurements and analytical solutions. We finally provide supplementary inter-comparisons using another SPH numerical model, based on the semi-analytical approach. © 2013 John Wiley & Sons, Ltd.

Girardi P.,54 Energy | Gargiulo A.,54 Energy | Brambilla P.C.,54 Energy
International Journal of Life Cycle Assessment | Year: 2015

Purpose: The purpose of the study is to compare the performances of two passenger cars: an electric vehicle (EV) and an internal combustion engine vehicle (ICEV) paying particular attention to the production of electricity that will charge the EV. Even if many similar comparative life cycle assessments (LCAs) exist (Nordelöf et al. J Life Cycle Assess 19(11):1866–18990, 2014), only few have focused their attention on evaluating which is the kind of electricity that will recharge EV batteries (Hawkins et al. Int J Life Cycle Assess 17(8):997–1014, 2012). Methods: Despite its relevance, many EV LCA studies have used a ready-to-use dataset to evaluate the power mix that supplies electricity to EV. The present paper tries to better define the power mix that recharges EV batteries in Italy according to the national power system and the national electric market rules. A 2013 and a 2030 scenario have been developed in order to understand effects in short and middle term. Life cycle inventory of electricity for EV has been estimated modifying available datasets according to official Italian data on power plants’ efficiency and emission rates. Finally, also for the ICEV use phase, existing dataset have been modified for fuel consumption and regulated emission according to the National Inventory Report results (ISPRA 2014) Results and discussion: In both 2013 and 2030 scenarios, the power mix that in Italy supplies energy to EV is dominated by fossil fuel power plants. Nevertheless, due to the fact that more than the 60 % of this energy is produced in efficient combined cycle gas turbine power plants, EV performs better than ICEV in almost all the impact categories considered except for human toxicity and eutrophication, the only two impact categories in which the EV car, mainly due to battery manufactory, presents more relevant potential impacts. ICEV impacts are always dominated by well to wheel phases (use phase and fuel production). EV car and battery manufacturing have higher impacts for all categories than ICEV car manufacturing. Conclusions: The study demonstrates that electricity supplied in Italy to EV today is, and will probably be in 2030, mainly produced by fossil fuel power plants. Nevertheless, the EV proves to be able to reduce, with respect to ICEV, those impacts it is supposed to reduce: air acidification, photochemical oxidant formation, and also greenhouse gases. Trade-offs are, as foreseeable, eutrophication and human toxicity due to EV car and battery manufacturing. © 2015, Springer-Verlag Berlin Heidelberg.

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