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Abstract The integration of distributed generation (DG) units into traditional distribution grids causes several significant changes in their characteristics like power flow direction, voltage profile and short circuit level. Therefore, the currently used control and protection strategies can no longer work properly and have to be revised and modified. The most important protection problems are e.g. blinding of protection, false tripping, unsynchronized reclosing. For a reliable and efficient protection system, both transient and steady states of fault current contributions should be considered. In this paper, in order to study the real impact of DG units on a given protection scheme, the fault current contributions generated with exact models of DG units including their interfaces with the grid and control system (photovoltaic generator, PSMG with full size converter, DFIG with partial size converter, commonly met on Belgian grids, and directly connected IG) are presented and compared with the ones that are generated by ideal models of DGs in the same conditions. The PSCAD software is used for the simulation of transient contributions of DGs under several faulty conditions in a tested medium voltage distribution grid.

Abstract Offshore Wind (OW) speed assessment is a key aspect for the development of new wind farms at sea. Satellites can be used to globally obtain ocean and sea distribution, compensating limited in-situ measurements. In this study, a new methodology to estimate the wind’s speed potential is here proposed. Preliminary, Sentinel-1 (S-1) images have been analyzed by means of the Sentinel Application Platform (SNAP) software, extrapolating wind speed data for each cell pixel size of a testing area. Then GIS (Geographic Information System) software has been used to map wind data and find the best pixel location comparing these data with in-situ data. Furthermore, wind speed has been analyzed using the ERA-Interim reanalysis dataset for areas within 11 km and 40 km from the Lillgrund OW farm in the Baltic Sea to better understand wind regimes. Finally, wind speed parameters obtained by S-1 in Sea Surface Water (SSW) with the 10 m standard high have been compared with wind speed recorded by Supervisory Control and Data Acquisition (SCADA) systems of two turbine using wind profile formula. Obtained results show the comparison accuracy of wind speed assessment for each center of the pixels by S-1 satellite images and in-situ (SCADA) measurements. Data actually depends on the distance between the selected center pixel and the location of the turbines. The obtained wind speed differences (0.26 m/s - RMSE = 1.38 and 0.92 m/s - RMSE = 1.82) pinpointed the direct effect of the distance between the selected pixel center and the in-situ measurements location in the S-1 imagery for wind speed potential assessment. Obtained results proved an improvement of the OW assessment accuracy using multiple satellite observations, demonstrating that SAR wind maps can support OW speed sites assessment by introducing observations in different phases of an OW farm project.

The aim of this chapter is to explore the gender dimension of different aspects of renewable energy in the North and South, in particular how renewable energies can contribute to gender equity so that both women and men benefit fairly from access to energy services. The term ‘gender’ is used here deliberately rather than ‘sex’. The term ‘gender’ refers to socially constructed roles of women and men rather than biologically determined differences. These gender roles of men and women, with their accompanying responsibilities, constraints, opportunities and needs, are defined by a particular society. Gender roles are learned by children as part of their socialization process. The roles change over time and vary widely within and across cultures. Men and women play different roles in both Southern and Northern societies, although at first glance the roles in the North may not be as clearly visible as they are in the South.

Abstract This work aims to get a better insight into the behaviour of CECO, an oscillating-body wave energy converter that presents a singular feature: the motion of its oscillating part is restricted to translations along an inclined axis. In order to study in the time domain the response of CECO for a wide range of wave conditions, a hybrid numerical approach based on the Boundary Element Method (BEM) and the Morison’s equation was used. The effects of the power take-off system were included in the numerical model and calibrated with the results from previous wave basin experiments. The results show that CECO is able to capture up to 40% of the incident wave energy when the direction of translation is 45°. However, if the direction of translation is vertical, the amount of captured wave energy decreases almost three times. This investigation demonstrates the advantage of limiting the oscillation of the CECO floating part to an inclined direction and reaffirms the concept as a promising technology for wave energy conversion.

The Global Geothermal Energy Database of the International Geothermal Association (IGA) is an internet-based platform providing access to the world geothermal production data. This platform is unique for the geothermal sector, and provides an excellent tool for showing geothermal use in the world and promoting the development of geothermal energy. The platform is also an important example of organization and access to widely distributed data, since it allows analyzing, synthetizing and quickly interpreting stored data. The global and country-specific information regard both electricity generation and direct use applications. The platform, which has been built using an open-source Business Intelligence application and can be accessed through the IGA website, allows to access, navigate and organize information in various ways. Data lists related to geothermal fields and plants, direct uses, geothermal turbine manufactures and geothermal companies can be accessed, aggregated and filtered, producing reports, charts and maps. Aggregation and filtering options synthetize and organize data for direct use, power plants and installed capacity by region, category and operative status. The mapping tool, providing geothermal fields location, power plants and direct uses geographical references, allows also map browsing, and to zoom, to measure distance, to pan and to query for further information. The chart analysis produces pie charts and bar diagrams of data, dynamically sorted and aggregated.

Super-hot rock geothermal is an emerging source of renewable and carbon-free energy. This paper is the first attempt to explore fluid and heat flow dynamics in the reservoir-wellbore coupled system, to assess the power generation performance of a super-hot (>450 °C) enhanced geothermal system (EGS). We developed a high-performance code and built a 3-D wellbore-reservoir coupled model based on data from a recently completed deep-drilling project at Larderello, Italy. The general pattern of the super-hot EGS is characterized by a significant temperature plummet (>60 °C), after which the production fluid evolves from steam to a two-phase mixture till the end of the operation period. Reservoir pressure emerges as a key parameter to determine the temperature of the two-phase mixture. By realistically capturing phase transitions driven by coupled thermo-hydraulic processes during operations, our numerical model predicts a lower power generation efficiency compared to previous attempts based on ultra-simplified models. Although finalized at assessing the thermodynamic viability of a specific system, this modeling approach provides general information on fundamental thermo-hydraulic processes in the Earth crust that might be applied for the design of similar EGS projects elsewhere.

Abstract Access to modern energy services is still low in developing countries and this lack of access affects in particular the Least Developed Countries (LDCs) and sub-Saharan Africa. The large majority of population in the Logone Valley at the border between Chad and Cameroon still relies on wood fuel burnt in smoky and inefficient fireplaces for cooking. The promotion of wood saving stoves locally produced and appropriate for the traditional cooking practices has been implemented by an international cooperation project. Two stove models were compared to the traditional 3-stone fire and a gas stove by Water Boiling Tests and Controlled Cooking Tests. The results showed significant fuel savings thanks to the use of the improved stoves. Data collected during the tests, crossed with information about the local cooking habits, allowed to estimate the impact, in term of money savings, on each household adopting an improved stove. The Centrafricain improved stove resulted being the most performing model occurring in a 25% reduction of the expenditure per family for cooking purposes in a short-medium term. This study witnesses that the use of improved wood stove is likely to be a sustainable way to achieve an appropriate minimum level of energy access for cooking purposes for the poor people in the LDCs, in particular in rural areas.

Abstract Recently, the attention towards Urban Building Energy Modelling has been growing due to the large contribution of cities on the worldwide energy consumption rate. In fact, many models have been developed to simulate buildings and urban energy systems. This article presents a new open-source tool for city-scale simulations. The platform implements the electrical analogy to model buildings thermal behaviour through resistance-capacitance networks, thus predicting the energy demand of urban areas with a bottom-up approach and low computational resources. The model has been applied to two urban areas: a small and well-known neighbourhood and a broader urban district. Results show the accordance of simplified models with respect to single building detailed simulations in the evaluation of the seasonal energy demand. When comparing results at hourly resolution, the accuracy is increased by considering a thermal network that splits buildings’ surfaces into two capacitances. A model based on a single capacitance leads to a higher deviation, especially on the daily peak power. Regarding the district simulation, these simplified networks show a good prediction of the buildings energy demand according to relevant European references, thus demonstrating the reliability of the proposed approach despite their low computational effort.