Combining methodologies on the impact of inter and intra-annual variation of wave energy on selection of suitable location and technology

In this study, based on 55 years’ worth of high-resolution simulated wave data using numerical modeling off the southern coasts of China, intra-annual and decadal variations of the wave climate and wave energy were evaluated. The results show that it is important to consider a sufficiently long time period for wave energy assessment to take into account the changing climate. The high-resolution wave dataset enabled the quantitative analysis in both nearshore and offshore, and the quantitative analysis was performed in two phases: First, using two different approaches. i.e., “Climate-dependent Sustainability Index” and “Wave Exploitability Index”, the wave power and its short and long-term changes were considered to prioritize the candidate stations for further assessment. Then, a modified “Multi-Criteria Approach” consisting of both sea state and Wave Energy Converters (WECs) was applied to determine the most suitable combination of WEC and location in the domain, which is Wave Dragon in the eastern parts of the domain with the energy production of around 92, 000 MWh for a single device. The results provide the quantitative analysis for different scenarios of development plans in the study area on the selection of appropriate location and technology

La irrupción del mercado energético en el medio forestal

El fomento de la implementación y el uso de fuentes de energías renovables en toda la Unión Europea, y también en España, entre otros efectos ha conseguido que ciertas materias primas que hasta hace relativamente poco tiempo tenían un uso estrictamente alimentario o celulósico, ahora también tengan un valor en el “mercado energético”. Las plantaciones forestales existentes en el norte de España se han destinado históricamente a dos fines comerciales: materia prima para pasta de papel y para la fabricación de tableros. Ahora existe otra opción de venta puesto que la madera puede ser valorizada energéticamente en plantas de biomasa. El objetivo de este trabajo consiste en analizar cómo puede afectar la entrada de plantas de biomasa a los actuales mercados y, en particular a los precios de las materias primas

The analysis of the form in the architectural design: from the project to the execution

[EN] For any given set of experimentally surveyed coordinates, there are some baseline data that are based on those we consider objective if we take care to specify the tolerances of the tools employed. The interpretation of the geometric model requires founded methodological reflections. In the present case study the question might be: what was the configuration of the façade’s projecting elements? The mathematical computation supports the hypothesis but it is the instrumental survey that legitimizes the choices in that it measures the gap between the numerical experimental model and the more abstract one of ideas. This information allows to set forth hypotheses concerning the conflicts generated during the execution work in progress.[ES] Para cada conjunto de datos de coordenadas experimentales, existen unos datos de partida que van en función de aquellos que consideramos objetivos si nos ocupamos de especificar las tolerancias de las herramientas empleadas. La interpretación del modelo geométrico requiere reflexiones metodológicas fundadas. En la presente investigación, la pregunta podría ser: ¿cuál fue la configuración de los elementos proyectados de fachada? El cálculo matemático apoya la hipótesis, pero es el ensayo con instrumentos el que legitima lo que hemos elegido, ya que determina la diferencia entre el modelo experimental numérico y el más abstracto de las ideas. Estas informaciones permiten definir hipótesis sobre conflictos generados durante los trabajos en ejecución.Rossi, A.; Palmero Iglesias, L.; De Gregorio, S. (2018). El análisis de la forma en el diseño arquitectónico: desde el proyecto a la ejecución. EGA. Revista de Expresión Gráfica Arquitectónica. 23(32):186-197. doi:10.4995/ega.2018.8942SWORD1861972332Docci, Mario. 1980. Presentazione. Pascucci, Achille. Superfici rigate in architettura. il paraboloide iperbolico. Roma: Kappa Edizioni.Frediani, Gian Luca 2001. Paolo Soleri e Vietri. Roma: Officina edizioni, ISBN: 9788887570229.Gei, Stefano. 2012. Ceramica e architettura nell'opera di Paolo Soleri. La fabbrica Solimene a Vietri sul Mare. La ceramica del Novecento a Napoli. Architettura e Decorazione. Napoli: Edizioni Fioranna, ISBN 978-88-97630-08-1Gregotti, Vittorio.1972. Il territorio dell'architettura. Milano: FeltrinelliLima, Antonietta Iolanda; Arnaboldi, Mario Antonio (ed.). 2004. Ri-pensare Soleri. Milano: Jaca Book, ISBN 88-16-40655-0Polano, Guido. 1991. Guida all'architettura italiana del Novento. Milano: Electa, p.506Ryan, Kathleen (ed). 2002. Paolo Soleri. Itinerario di architettura. Antologia degli scritti. Milano: Jaca Book. ISBN:88-16-40630-5 EAN: 9788816406308Rossi, Adriana. 1995. Dal vaso all'architettura della ceramica. Il disegno luogo e memoria, Firenze: Alinea, p. 360-367, ISBN: 88-8125-034-9Rossi, Adriana. 2013. The ethos suggested by landscape markers: the tiled dome. Domes and Cupolas, 1(1), pp. 85–91.Soleri, Paolo. 1969. Arcology: The City in the Image of Man. Cambridge MA: MIT Press. ISBN 0-262-69041-1Venezia, Francesco; Petrusch, Gabriele. 1983. In forma elicoidale. Gran Bazar, 5-6, p.166-167.Wright, Frank Lloyd. 1932. An Autobiography. New York: Promegranate Communication

A numerical refraction-diffraction model in the ray-front coordinate system

4th World Congress on Computational Mechanics, 1998, Buenos Aires[Resument] A model for the propagation of water waves is presented, which retrieves the concepts of rays and fronts from the geometrical optics approximation. Their definition here is nevertheless different in that it considers both refraction and diffraction, solving thus most of the problems usually associated with ray method

Numerical Modelling of a Floating Wind Turbine Semi-Submersible Platform

A detailed study is undertaken of the computational modelling of a sub-platform for floating offshore wind using the software Star-CCM+ with the application of the RANS approach. First, a mathematical introduction to the governing equations is carried out. Then, the computational grid is defined, and the grid-independence of the solution is verified. A time-dependent study is performed with the selected time-step. Finally, two examples of 3D decay tests in heave of the sub-platform without and with moorings are presented, accompanied by a damping factor study, with the aim of providing a better understanding of the hydrodynamic damping of the platform. Throughout the process, three degrees of freedom (DoFs) are locked due to the limitations imposed by the use of a symmetry plane; this implementation allowed us to reduce the computational cost of each simulation by 50%. Therefore, three DoFs (heave, surge and pitch) are considered. The coupling study, adding a mooring system in the decay tests and the regular wave tests, shows good agreement between the experimental and computational results. The first half-period of the simulations presents a greater discrepancy due to the fact that the damping of the platform is lower in the computational simulation. However, this does not imply that the hydrodynamic damping is underestimated but may be directly related to the lock of various DoFs associated with the hydrodynamic damping.The current investigation was developed under the framework of the European Regional Development Fund through the “Interreg Atlantic Area Programme” under contract EAPA 344/2016, providing experimental inputs to complete this study

The Enhancement of local Resources: research, Teaching and experimentation in L'Aquila

[EN] The construction sector has a major impact on current environmental issues. Through cost-effectiveness, it is possible to encourage construction sector operators to trigger voluntary environmental protection mechanisms. The use of local resources (including waste materials) is one of the possible strategies but requires specific and interdisciplinary training involving many aspects, including context analysis, demolition management, durability and reversibility control, and the ability to identify the performance of the construction system. The paper illustrates a path of research, teaching and experimentations concluded with the design and realization in self-construction of temporary modules, reusing waste materials from post-seismic reconstruction in L¿Aquila.De Gregorio, S.; De Berardinis, P.; Palmero Iglesias, LM. (2020). The Enhancement of local Resources: research, Teaching and experimentation in L'Aquila. TEMA. 6(1):86-95. https://doi.org/10.30682/tema0601hS86956

Coastal Cliff Exposure and Management

[Abstract:] Coastal cliffs cover about 75% of the world's coastlines. Many of these cliffs suffer severe erosion problems, which are mainly caused by wave action and lead to important damages. The main objective of this work is to propose and apply a methodology to characterize and map wave exposure levels for the management of cliff coasts. The methodology proposed consists of a number of steps. First, a statistical characterization of the wave climate in deep water is performed. Second, relevant sea states are propagated towards the cliff by means of a numerical model. Then, the results are used to assess the distribution of significant wave heights and wave power along the cliff toe. Finally, four exposure levels are defined based on the wave power values at the cliff, and exposure zones are mapped accordingly along the cliff. This approach is illustrated with a case study – the Catedrales Cliffs and Beach, a tourism hotspot in Galicia (NW Spain) where erosion caused loss of human life. We find that exposure levels are primarily influenced by the nearshore bed morphology, which controls wave refraction, shoaling and breaking, as well as by the geometry and orientation of the cliff, with some parts more exposed than others to the prevailing wave direction. On the islets off the cliff the windward faces have a greater level of exposure, since the leeward faces are protected by the islets themselves and lower water depths. The rocky outcrops that occur at the cliff toe in some sections act as emerged (submerged) breakwaters under low (high) tide conditions, dissipating wave power and thus reducing wave exposure. The methodology proposed in this work enables coastal managers to prevent the personal and material damages derived from cliff erosion by focusing remedial measures where they are most needed.Ministerio de Ciencia, Innovación y Universidades; FJCI-2017-3178

Wind resource evolution in Europe under different scenarios of climate change characterised by the novel shared socioeconomic pathways

Wind energy is a fundamental pillar of the energy mix in Europe ? hence the need for understanding the evolution of the wind energy resource under climate change. For this purpose, near-, mid- and long-term wind speed projections from 18 global climate models are considered and a multi-model ensemble is constructed with the ones found to best reproduce past-present conditions. The evolution and temporal variability of wind power is investigated considering different climate change scenarios through the novel Shared Socioeconomic Pathways (SSPs). More specifically, two SSPs are considered, each corresponding to its own socio-economic and political environment and, therefore, its own level of greenhouse emissions: SSP5-8.5 (highest emissions scenario) and SSP2-4.5 (intermediate emissions scenario). Both scenarios lead to a significant reduction (up to 35%) in wind power density in northern Continental Europe and the Central Mediterranean, and an increase of similar magnitude in West Finland. Over the Atlantic Ocean, Ireland and Britain the resource is also projected to decrease significantly. In other regions, however, the general trend (positive or negative) depends on the SSP scenario. This is the case, notably, of Central Europe, with considerable growth in SSP2-4.5 but some reduction in SSP5-8.5. Thus, in the intermediate emissions scenario (SSP2-4.5) both growth and decline in wind power density are forecast, depending on the region. By contrast, in the highest emissions scenario (SSP5-8.5) the forecast is a general decrease, of the order of 15% overall, with an annual rate of change of approximately ?0.2% and an increase in seasonal variability. These trends will affect the energy production of wind farms and, therefore, need to be accounted for in assessing wind power projects in Europe

Multi-parameter analysis and mapping of the levelised cost of energy from floating offshore wind in the Mediterranean Sea

Floating offshore wind, far less constrained by water depths than bottom-fixed, has great potential in the Mediterranean Basin. The levelised cost of energy (LCOE) is arguably the single most reliable metric to measure the viability of energy projects. In this work, the levelised cost of energy for floating offshore wind is mapped for the first time in the European and Eastern Mediterranean with a detailed cost breakdown and a focus on semi-submersible platforms. A multi-parameter analysis is conducted in a case study to discern the effects of specific elements on the LCOE. Expressions are formulated as functions of site-specific variables: distance to shore, water depth and annual energy production. The latter is estimated accurately by combining the power curve of an exemplar wind turbine with hindcast, site-specific wind data. The mapping shows the paramount importance of the wind climate, i.e., the resource, for the LCOE. The lowest values (similar to 95 (sic)/MWh) occur where the wind resource is most abundant, i.e., the Gulf of Lion and the Aegean Sea. The highest values (>250 (sic)/MWh) are found where the resource is scarce, i.e., around the Balearic Islands and in the North Adriatic, Tyrrhenian and Levantine Seas. Moderate values of the LCOE (130-180 (sic)/MWh) occur off South Spain (Alboran Sea), Sardinia, Sicily and Malta, and in the South Adriatic. In addition to the local wind resource, other parameters that play a relevant role in the LCOE are those related to the production of energy (number of turbines in the wind farm and installed power), on the one hand, and to substantial sources of costs (cost of turbines and substructure), on the other, as well as the project lifetime and discount rate. These results identify hotspots for the deployment of floating offshore wind in the Mediterranean and opportunities for cost reductions, and contribute to decision-making in a region much in need of renewable energy

Climate change impacts on wind energy resources in North America based on the CMIP6 projections

The mid-and long-term evolution of wind energy resources in North America is investigated by means of a multi model ensemble selected from 18 global climate models. The most recent scenarios of greenhouse gases emissions and land use, the Shared Socioeconomic Pathways (SSPs), are considered - more specifically, the SSP58.5 (intensive emissions) and SSP2-4.5 (moderate emissions). In both scenarios, onshore wind power density in the US and Canada is predicted to drop. Under SSP5-8.5, the reduction is of the order of 15% overall, reaching as much as 40% in certain northern regions - Quebec and Nunavut in Canada and Alaska in the US. Conversely, significant increases in wind power density are predicted in Hudson Bay (up to 25%), Texas and northern Mexico (up to 15%), southern Mexico and Central America (up to 30%). As for the intra-annual variability, it is poised to rise drastically, with monthly average wind power densities increasing up to 120% in certain months and decreasing up to 60% in others. These changes in both the mean value and the intra-annual variability of wind power density are of consequence for the Levelised Cost of Energy from wind, the planning of future investments and, more generally, the contribution of wind to the energy mix