Search

The growing share of electricity production from solar and mainly wind resources constantly increases the stochastic nature of the power system. Modelling the high share of renewable energy sources – and in particular wind power – crucially depends on the adequate representation of the intermittency and characteristics of the wind resource which is related to the accuracy of the approach in converting wind speed data into power values. One of the main factors contributing to the uncertainty in these conversion methods is the selection of the spatial resolution. Although numerical weather prediction models can simulate wind speeds at higher spatial resolution (up to 1 × 1 km) than a reanalysis (generally, ranging from about 25 km to 70 km), they require high computational resources and massive storage systems: therefore, the most common alternative is to use the reanalysis data. However, local wind features could not be captured by the use of a reanalysis technique and could be translated into misinterpretations of the wind power peaks, ramping capacities, the behaviour of power prices, as well as bidding strategies for the electricity market. This study contributes to the understanding what is captured by different wind speeds spatial resolution datasets, the importance of using high resolution data for the conversion into power and the implications in power system analyses. It is proposed a methodology to increase the spatial resolution from a reanalysis. This study presents an open access renewable generation time series dataset for the EU-28 and neighbouring countries at hourly intervals and at different geographical aggregation levels (country, bidding zone and administrative territorial unit), for a 30 year period taking into account the wind generating fleet at the end of 2015. [ABSTRACT FROM AUTHOR]

The amount of wind energy entering the European electricity transmission system is expected to increase in next decades. Indeed, Europe is on the path towards a deep transformation of its energy system, triggered in part by Directive 2009/28/EC (also known as the Renewable Energy Directive), in which wind energy will play an important role. Europe is large enough to be impacted by multiple weather systems at any one time and as a consequence, absolute values and time patterns of wind power generation are different in each European country because of these non-homogeneous meteorological conditions. A future pan-European power transmission grid aiming to dispatch electricity production throughout the continent will thus have to face the challenge of balancing in real time differently intermittent and strongly inhomogeneous resources. In this study, based on the wind fields provided at daily resolution for the period 1961–2050 by 12 regional climate models involved in the ENSEMBLES climate modelling intercomparison project, we have evaluated absolute national and European wind power production and its expected changes following the evolution of climate in Europe. Moreover, we have suggested a methodology to investigate in a quantitative way the complementarity among wind power patterns in different countries. Results show that the evolution of climate in Europe as projected by the ENSEMBLES participants, is not expected to have major impact on absolute wind energy production. Furthermore, the complementarity of wind energy patterns in different countries can be exploited by better integration of trans-boundary power exchange in Europe. For this reason, results are also discussed in the light of the design and dimensioning of the European electricity transmission system, with a special emphasis on the cross-border interconnections issues. [ABSTRACT FROM AUTHOR]

The European Union has committed itself to ambitious targets of Renewable Energy and bioenergy is expected to play a major role, increasing its contribution to Gross Final Energy Consumption from 2458 PJ in 2005 to 4605 PJ by 2020. Agricultural crop residues are considered a reliable resource for energy uses but important concerns still exist on the potential depletion of Soil Organic Carbon (SOC) stocks that may partially offset the environmental suitability and convenience of their large-scale exploitation. This paper provides an estimate of available agricultural residues and related potential energy production obtainable without impacting the EU SOC stock showing how SOC content preservation imposes the application of different collection rates for agricultural residues across the EU, depending on factors such as climate, soil type, current farming practices and pre-existing cultivation history. The results suggest that a potential amount of residues of 146,000 kt/year of dry matter leading to a potential gross energy production of about 2300 PJ/year could be obtained in EU-27 1 1 Excluding Croatia. without impacting the current SOC stocks. Agricultural residues are then theoretically able to provide a substantial contribution to renewable energy targets in several EU-27 countries as well as accommodating competitive uses and SOC preservation. Nevertheless, the spatial pattern of results also clearly indicates regions and countries where residues exploitation should be handled with care and current practices on residues collection are risky in term of SOC content. The estimate provided builds on results from previous studies (e.g., Scarlat et al. Waste Manage 2010;30:1889–1897, Monforti et al. Renewable Sustainable Energy Rev 2013;19:666–677) and on the analysis of future scenarios of SOC content obtained from an innovative pan-EU modelling platform (Lugato et al. Global Change Biol 2014;20:313–326. doi:10.1111/gcb.12292. Such an integrated approach, making use of soil, climate and energy transformation modelling, is unique and constitutes a substantial applied value for assessing the sustainability of crop residues use. [ABSTRACT FROM AUTHOR]

The paper introduces a transparent methodology to assess new suitable locations for mini and small hydro power plants in Europe. The expansion of hydro electricity production is a policy focus not only in Europe, but in the US (Hydropower Regulatory Efficiency Act of 2013) and in the developing world as well. The analysis of the technical potential points out the exact geographical locations and their corresponding capacities instead of only a theoretical potential; therefore it can serve as a reference for the policy debate over the sustainable management of water resources. This debate is reflected already in two major European policies: the Water Framework Directive (WFD) (2000/60/EC) and the RES Directive (2009/28/EC) on the promotion of the use of energy from renewable sources. As both policies have major influence on the priorities of water use, it is important to identify water management practices capable of accommodating sustainable energy purposes while maintaining water quality objectives at the same time. As the WFD poses limitation on the further expansion of large scale hydro options in the European water bodies, the present study focuses on local mini and small hydropower options and their suitability mapping. The presented, geographically explicit method is based on geospatial analysis and the results can contribute to the prioritization of potential hydro power sites in order to improve water quality and its use for energy simultaneously. [ABSTRACT FROM AUTHOR]

Abstract: Wind and solar energy are expected to play a major role in the current decade to help Europe reaching the renewable energy penetration targets fixed by Directive 2009/28/EC. However, it is difficult to predict the actual production profiles of wind and solar energy as they depend heavily on variable meteorological features of solar radiation and wind speed. In an ideal system, wind and solar electricity are both injected in a fast reacting grid instantaneously matching supply and demand. In such a system wind and solar electricity production profiles should complement each other as much as possible in order to minimise the need of storage and additional capacity. In the present paper the complementarity of wind and solar resources is assessed for a test year in Italy. To achieve this goal we employ data at high spatial and temporal resolution data for both solar radiation and wind speed in Italy obtained from running two state of the art models (PVGIS and MINNI). Hourly profiles for solar and wind energy produced are compared in each 4 × 4 km2 grid cell in Italy for 2005, and hourly, daily and monthly correlation coefficients are computed in order to assess the local complementarity of the two resources. A Monte Carlo approach is also developed to estimate how large-scale wind and solar energy productions could be potentially involved to complement each other in a scenario with up to 100 production sites across Italy. The results show how local complementarity can be very interesting with monthly correlation coefficients reaching values lower than −0.8 in several areas. Large-scale complementarity is also relevant with nation-wide monthly correlation coefficients showing values between −0.65 and −0.6. These model results indicate that in this sample year of 2005, wind and solar energy potential production have shown complementary time behaviour complementary, favourably supporting their integration in the energy system. [Copyright &y& Elsevier]

Abstract: This paper provides a geographical assessment of potential bioenergy production in the European Union from residues of eight agricultural crops (wheat, barley, rye, oat, maize, rice, rapeseed and sunflower). The evaluation is geographically explicit at the scale of 1km2 and is based on two main computational steps. In the first step the amount of crop residues resulting from statistical assessment based on the methodology developed by Scarlat et al. [1] have been spatially allocated on the EU-27 1 [1] The EU-27 expression symbolizes the current status of EU enlargements. Further information: http://epp.eurostat.ec.europa.eu/statistics_explained/index.php/Glossary:EU-27. territory using several auxiliary geospatial layers describing, for example, land cover, expected biomass productivity derived from soil parameters, climatic zones and topographical conditions. In the second step the number of model power plants (i.e., plants with a size of 50MW thermal input and a raw material demand of about 100kt/yr might be conveniently fed with available crop residues was estimated on the basis of two different allocation strategies implying a different grade of optimization. The results show that the estimated crop residue resources in EU-27 could provide fuel for about 850 plants expected to produce about 1500PJ/yr. Mobilization needs for the residues are also estimated, leading to a total amount of 1.5×1012–2×1012 tkm are necessary for the full potential exploitation. [Copyright &y& Elsevier]

Abstract: THOSCANE (Tool for HOurly Specification of CORINAIR ANnual Emissions) a software tool aimed at elaborating the emission inventories produced on the basis of the CORINAIR methodology for the needs of air quality modelling community, is presented here. Air quality modellers usually need very detailed information about emissions in the area studied. Also when a box model is applied, not considering spatial features of the emissions, other details have to be inferred from the inventory in order to correctly feed the model: the hourly time profile is usually required for all pollutants, whereas details on particulate matter size spectrum and chemical composition are necessary when dealing with PM modelling and suitable speciation profiles of emitted volatile organic compounds (VOCs) is a stringent requirement for modelling complex photochemical processes in the atmosphere. THOSCANE handles the emission inventory and all these profiles to obtain detailed emission patterns suitable for complex atmospheric box models. [Copyright &y& Elsevier]

The pernicious effects of deposition of airborne particles on monumental stones have been widely demonstrated, but estimates of deposition fluxes on historic buildings remain a hard task because of the lack of careful experiments and modelling. AERBOX is a new box model developed by ENVIROWARE and ENEA, simulating the whole life cycle of aerosols. AERBOX takes into account all the relevant chemical and physical processes involved: emission, chemical reactions in gas and in gas–liquid phases, deposition, entrainment, condensation and nucleation. Concentration and deposition rates of 52 species of gaseous pollutants and 14 species of particulate pollutants are calculated on hourly basis.A modelling system composed by AERBOX and the emission pre-processor Tool for Hourly Speciation of CORINAIR Annual Emissions (THOSCANE) has been applied to estimate the flux of particulate matter deposited on the monumental area of Florence downtown starting from a CORINAIR emission inventory developed by the Tuscany Region including the industrial and mobile sources in the area of Florence and Prato counties. The time and chemical profiles of the emissions have been adapted to the Tuscany region from the reference profiles given by both the California Air Resource Board and EPA and meteorological inputs were given by the Tuscany Meteorological Centre. Concentrations and deposition fluxes were compared with field measurements available in the open literature. [Copyright &y& Elsevier]

Abstract. This study simulates the exposure of V79 Chinese hamster fibroblasts to low-energy protons, deuterons and alpha particles in the LET range 10-200 keV/ mu m. The starting assumption is that the induction of clustered lesions in DNA is a fundamental step for cell inactivation. A non-homogeneous cell population was simulated by a computer program, using as input measured morphological parameters reported in the literature. Variations in the number of traversals through each cell of the population and in the length of the traversal, depending on actual nuclear thickness and position of the traversal, the energy spread of the incident beam, and the change of LET along the tracks were included in the simulation. Microdosimetric spectra were computed and compared with spectra obtained neglecting particle slowing-down and stochastic aspects of cell morphology. Simulated cell survival was estimated under the assumption that surviving cells are those with no clustered DNA lesions or no passages. The main features of experimental RBE versus LET and particle type were reproduced by the simulations. The influence of stochastic aspects of target-cell morphology and of the energy of the incident particles on survival were investigated under different assumptions about the correlation between morphological parameters. Results support the hypothesis of a relevant role of clustered DNA damage in cell killing and point out the importance of target-cell morphology and its variability in beam dosimetry and computer simulations of low-energy particle radiation effects. [ABSTRACT FROM AUTHOR]

Abstract: An experiment aimed at comparing particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) concentrations produced in a road tunnel by buses is described. The experiment took place in 2001 in Bologna when a couple of buses belonging to the public transport fleet where driven backwards and forwards in a road tunnel closed to all other vehicles. Buses run in the tunnel for 8h a day for 4 experiment days, each day using a different fuel: biodiesel, diesel–water emulsion, diesel–water emulsion with low sulphur content and commercial diesel. Average daily concentrations of PM of different sizes and of 12 PHAs were measured and comparison between different fuels was attempted in order to assess “real-world” exhaust emissions of different fuels. Due to heterogeneity of experimental conditions in different days and the relatively large measurement uncertainties, the effort was only partially successful, and it was not possible to state any firm conclusion on fuels reliability even if some indications in agreement with literature were found. Nevertheless, the experiment and the data analysis method developed could be of interest as a methodological approach for future experiments aimed at evaluating “real-world” exhaust emissions of single vehicles. [Copyright &y& Elsevier]

Purpose: To investigate the mechanisms underlying the induction of chromosome aberrations by ionizing radiation, focusing attention on DNA damage severity, interphase chromosome geometry and the distribution of DNA strand breaks. Methods: An ab initio biophysical model of aberration induction in human lymphocytes specific for light ions was developed, based on the assumption that 'complex lesions' (clustered DNA breaks) produce aberrations, whereas less severe breaks are repaired. It was assumed that interphase chromosomes are spatially localized and that chromosome break free-ends rejoin pairwise randomly; the unrejoining of a certain fraction of freeends was assumed to be possible, and small fragments were neglected in order to reproduce experimental conditions. The yield of di erent aberrations was calculated and compared with some data obtained using Giemsa or FISH techniques. Results: Dose-response curves for dicentrics and centric rings (Giemsa) and for reciprocal, complex and incomplete exchanges (FISH) were simulated; the ratio between complex and reciprocal exchanges was also calculated as a function of particle type and LET. The results showed agreement with data from lymphocyte irradiation with light ions. Conclusions: The results suggest that clustered DNA breaks are a critical damage type for aberration induction and that interphase chromosome localization plays an important role. Moreover, the e ect of a given particle type is related both to the number of induced complex lesions and to their spatial distribution. [ABSTRACT FROM AUTHOR]

Purpose : To measure clonogenic death of Chinese hamster V79 cells following exposure to a defined number of 4.3 MeV alpha particles (track-averaged LET 105 keV/ mu m). Materials and methods : Cells were irradiated at the radiobiological facility installed at the TTT-3 Tandem accelerator in Naples by using a 'Biostack' approach, which allows the positions of incident tracks relative to cells to be carefully determined. Subcellular structure was identified by fluorescence microscopy, while tracks were visualized by LR-115 solid state nuclear track detectors. Results : Particle hits in the cytoplasm did not significantly affect cell survival, yet survival probability decreased exponentially as a function of the number of nuclear traversals. Measured probability of surviving to exactly one 4.3 MeV alpha -particle traversal in the cell nucleus was 0.67 0.10. Inactivation cross-section was substantially higher than expected from conventional survival curves. However, folding of the data with Poisson statistics showed that survival level expected if a mean of one alpha -particle goes through a nucleus is higher than the measured value after exactly one particle traversal. Conclusions : V79 cells have about 67% probability to survive a single alpha -particle traversal in the cell nucleus. Single-particle survival curves are consistent with conventional dose-survival relationships, once Poisson distribution of traversals is taken into account. [ABSTRACT FROM AUTHOR]