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[en] Under the current macro-economic trends, the so far abundant support system for renewables (mainly in the form of feed-in tariffs and quota systems) has been drastically modified. In many EU countries, companies are trying to find alternative ways to secure financing for their renewable energy projects. Therefore, new ways of attracting private capital for the realisation of green energy goals have to replace the old schemes. Some new forms of financing are coming together with the EU Cohesion Policy 2014-2020 (project guarantees, packaging of small project for micro-financing schemes at the regional level, preferential loan instead of subsidies etc.). Advanced financial structures are likely to play an increasingly important role in the allocation of risk and reward among different investor classes. The finance and investment gap needs to be filled by the private sector. The challenge is to identify the appropriate policy options and financial tools to attract and scale-up private investments. There are, however, already innovative and promising business and financial models to promote the deployment of RES in the EU. The aim of the EurObserv'ER case studies is to find such examples and describe them so as to put forward the best practices and the replicability of the future promising financing mechanisms. EurObserv'ER will aim at choosing only the most promising ones and try to describe them in order to promote replicability in other geographical areas. The selection criteria for the choice of case studies should ensure (i) diversity across regions and RES, (ii) diversity across finance instruments/mechanisms, (iii) success of approach and its potential to be replicated, (iv) and a wide range of the 'size' of actors/ investors and the resulting RES investments (capacity). The current selection also takes into account the fact that there were already some case studies published in the 2014 and 2015 barometers. These are also available for download on the project website: www. eurobserv-er.org
[en] In any solar thermal application, such as solar space heating, solar hot water for domestic or industrial use, concentrating solar power, or solar air conditioning, a solar receiver converts incident sunlight into heat. In order to be efficient, the receiver must ideally absorb the entire solar spectrum while losing relatively little heat. Currently, state-of-the-art receivers utilize a vacuum gap above an absorbing surface to minimize the convection losses, and selective surfaces to reduce radiative losses. Here we investigate a receiver design that utilizes aerogels to suppress radiation losses, boosting the efficiency of solar thermal conversion. We predict that receivers using aerogels could be more efficient than vacuum-gap receivers over a wide range of operating temperatures and optical concentrations. Aerogel-based receivers also make possible new geometries that cannot be achieved with vacuum-gap receivers.
[en] The transformation of the global energy supply is taking place primarily in the accelerated growth dynamics of the increasing share of renewable energies for power generation. In the last decade, renewable energies accounted for more than 60% of the total investments made worldwide in power generation each year. The capacity of power generation plants based on solar, wind, hydro, bio, geothermal and ocean energy more than doubled between the end of 2010 and the end of 2019 - favored by government subsidies and a strong cost degression. In the course of this development, the share of renewable energies in global electricity generation has steadily increased and reached a new record level of 26.0 % in 2019. This means that renewable energies are now - after coal - the second most important source of energy for electricity supply.
[de]Die Transformation der globalen Energieversorgung findet vor allem in der beschleunigten Wachstumsdynamik beim Ausbau erneuerbarer Energien zur Stromerzeugung statt. Auf erneuerbare Energien entfielen im letzten Jahrzehnt jedes Jahr über 60 % der gesamten Investitionen, die weltweit in der Stromerzeugung getätigt wurden. Die Kapazität der Stromerzeugungsanlagen auf Basis von Sonne, Windenergie, Wasserkraft, Bioenergie, Geothermie und Meeresenergie hat sich von Ende 2010 bis Ende 2019 - begünstigt durch staatliche Förderung und eine starke Kostendegression - mehr als verdoppelt. Im Zuge dieser Entwicklung hat sich der Anteil erneuerbarer Energien an der globalen Stromerzeugungsmenge stetig erhöht und 2019 einen neuen Rekordstand von 26,0 % erreicht. Damit sind erneuerbare Energien inzwischen - hinter Kohle - die zweitwichtigste Energiequelle zur Stromversorgung.
[en] The European Union solar thermal market for heat, heating, and domestic hot water production held up well in 2019. Initial estimates put the total installed collector area at just under 2.3 million m2, which is a slight increase (1.5%) on its 2018 level. However, individual country situations vary, and the sector still has to reinvent itself to meet the huge challenge of climate neutrality. The term Concentrated Solar Power (CSP) covers all the technologies that aim to transform solar radiation energy into very high temperature heat to convert it into electricity. Most of the current CSP development is going on in countries and regions that offer suitably conducive sunlight conditions, such as China, India, Australia, South Africa, the Middle East, and the Maghreb. The European Union's new CSP plant installation pace slowed down considerably after an initial flurry concentrated in Spain between 2007 and 2014. In 2019, the European Union gauge moved up slightly to 2 323 MW when the eLLO project in the Pyrenees-Orientales, France, officially came on stream.
[en] We present the development of a thermal-hydraulic-solar model (MTHS) for design and numerical simulation of solar thermal conversion systems. Unlike empirical tests usually published in national journals, that gives the temperature evolution a tank of collector fixed in a given location, the MTHS is a powerful tool that, not only simulates this case, but also allows to extrapolate collector behavior for different weather patterns (such as ambient temperature Ta (t), solar radiation I (t), etc.) for any day of the year, at any latitude of the country, thus allowing maximize the efficiency of the collector in each particular case. The model takes into account in its equations the characteristic parameters of a collector, such as: optical efficiency “ao”, and the overall heat loss coefficient “a1”, what defined efficiency collector “μ”. The model also includes the geometrical parameters of a collector, such as length and diameter of the absorber (values that determine the pressure drop of hydrodynamic circuit), it also uses the positioning data such as azimuth angle “β” of the absorber, and the height of tank “Δh” (values of which depends heavily the buoyant force needed to establish the natural convection in the collector). (author)
[es]Se presenta el desarrollo de un modelo termo-hidráulico y solar (MTHS) para el diseño y simulación numérica de sistemas de conversión solar térmica. A diferencia de los ensayos empíricos habituales en publicaciones nacionales, en los cuales se mide la evolución de la temperatura del tanque de un colector emplazado en cierto lugar, el MTHS es una poderosa herramienta que no solamente simula lo anterior, sino que además permite extrapolar el comportamiento del colector para diferentes patrones climáticos (como temperatura ambiente Ta(t), radiación solar I(t), etc.) para cualquier día del año, en cualquier latitud del país, permitiendo de esta manera poder maximizar el rendimiento del colector en cada caso particular. El modelo tiene en cuenta en sus ecuaciones los parámetros característicos de un colector, como ser: la eficiencia óptica “ao”, y el coeficiente de pérdida global de calor “a1”, ambos definen la eficiencia “μ” del mismo. Además contempla los parámetros geométricos constructivos de un colector, como ser longitud y diámetro del absorbedor (valores que determinan la pérdida de carga hidrodinámica del sistema), y área de colección; además de las variables de ubicación como el ángulo de elevación acimutal “β” del absorbedor, y la altura o desnivel del tanque “Δh” (valor del cual depende fuertemente la fuerza boyante que origina la convección natural en el colector). (author)
[en] Ocean Thermal Energy Conversion, OTEC, is a concentrated renewable source of energy available in the one third of the world's ocean lying in the tropics. An OTEC plant is a heat engine fed with warm surface water and cold water pumped up from the deep. The difference of temperature, 20 deg. C, is small, it can be used to produce electricity as well as fresh water. Plants can be installed on land or at sea. The main problem is to build and deploy a large diameter pipe to pump the cold water from 600 to 1000 m in depth. France, who discovered the idea realised some major demonstrations fifty years ago. More recently US and Japanese firms have spent more than dollars 200 million to develop prototypes and research in this field. Several major OTEC pilot plants are presently discussed mainly by US, Japanese and French teams. The main challenge is to prove the potential competitiveness of OTEC electricity in the 10 to 100 MWe range, with diesel electricity in the 1990's. Production of OTEC desalination water and marine proteins are also under consideration. The present book give a unique overview of both technical and economic aspects of this promising source of energy. (author)
[fr]L'Ocean presente un potentiel considerable d'energie renouvelable. Dans ce domaine, l'energie thermique des mers (ETM) apparait tres riche de promesses. C'est une idee francaise: elle est due a d'Arsonval (1881). Les travaux de G. Claude et P. Boucherat (1928-1934), les projets d'Abidjan (1940-1956) et de la Guadeloupe (1958) essaieront de la materialiser. Depuis les annees 60, ce sont surtout les Americains et les Japonais qui developpent les recherches. La France a repris ses projets a partir de 1978, de meme que certains pays d'Europe. Cet ouvrage expose les caracteristiques de l'ETM et fixe les ordres de grandeur qui permettent de dimensionner les composants d'une centrale. Il rend compte des recherches menees dans differents pays pour maitriser la technologie ETM:aux etats-Unis, au Japon, en Grande-Bretagne, en Suede, en France et, plus recemment, en Inde ou a Taiwan. Il examine les potentialites reelles dans 98 pays et territoires qui ont acces au gisement ETM et dont les 2/3 sont dans la mouvance europeenne. L'etude traite enfin du cout de cette energie dans la perspective d'une competitivite du KWG/ETM avec le KWG/fioul. L'examen porte ainsi sur d'autres actions possibles: production eau douce, aquaculture, froid
[en] Highlights: • A novel cermet WTi-Al2O3 is designed for constructing solar absorbing coatings. • The resultant coating exhibits an excellent thermal tolerance at 600 °C. • The coating has a low infrared emissivity of ~10.3% @500 °C after 600 °C annealing. • A mechanism is proposed based on the self-passivation of WTi alloy nanoparticles. Cermet-based solar selective absorbing coatings are widely used, however, the long-term thermal instability and pretty high infrared emissivity at high temperatures (>550 °C) are still challenging issues to be addressed, which essentially lies in suppressing the growing up and agglomeration behaviors of metal nanoparticles (NPs) and maintaining the interface integrity in the multi-layer stacked structure. Herein, we develop and explore WTi-Al2O3 cermet-based absorbing coatings, demonstrating a solar absorptance of ~93% and a very low thermal emissivity of 10.3% @500 °C even after annealing at 600 °C for 840 h in vacuum. It is revealed that the surface segregation of solute Ti atoms from the parent alloyed NPs and their partial oxidation to form protective layer restrain outward diffusion of W element, agglomeration of NPs, and interface structure degradation, in favor of enhancing the thermal tolerance of the coatings. These results suggest that the WTi-Al2O3 based absorbing coating is a good candidate for high-temperature solar thermal conversion.
[en] In order to increase Renewable Energy (RE) in the power generation, the present technology of Nuclear Power Plants (NPPs) should be utilized. This paper introduces a ‘Thermal Hub’ concept which consists of the two hybrid systems with Concentrated Solar Power (CSP) for the heating steam in the reheater and Ocean Thermal Energy Conversion (OTEC) for waste heat recovery of discharged water from the NPP. These renewables were chosen based on the NPP’s thermodynamic characteristics. Both thermal hybrid systems will contribute to reduce the cost for the electricity of renewables. A useful chart is introduced for visualization of the relationship between nuclear and renewable energies in the various hybrid systems. (author)
[en] School buildings differ from other types of buildings because they are where our children are educated and have the opportunity to learn how to become environmentally-aware citizens. It is therefore essential that schools set a good example regarding efficient fossil energy utilisation, pollution control, environmentally-friendly material selection, quality of life, users' comfort, etc. These experiences can serve as teaching aids for educational developments to raise awareness about different energy resources and their possible sustainable use. All European municipalities have some involvement in managing, retrofitting and/or building schools. They are also concerned about balancing the municipal budget. Some existing schools have very high energy consumption due to poor design, operation or maintenance. Such schools would clearly benefit from energy efficiency improvements. New schools, if properly designed and constructed, can achieve extremely low energy use. Hence, there are significant attractions for municipalities to opt for sustainable solutions which involve energy efficient technologies and measures. This is the challenging background which led to the production the Guide to Sustainable Energy Technologies for Schools. This guide is a decision-making tool intended for European municipalities and school managers. Its aim is to: - assist them in choosing between the energy technologies that will be used in school building or retrofitting projects, - provide them with a framework for measuring and comparing different aspects of energy performance that can be used to convince decision-makers to select sustainable energy technologies and measures. The guide is composed of three parts: - An illustrative list of sustainable energy technologies, - An introduction to energy performance indicators, - Fifteen case studies describing practical sustainable energy solutions applied to schools in seven European countries.
[en] The ocean energy sector has been a beehive of activity over the last three years with many prototypes being submerged off the British, Brittany, North Sea and Mediterranean coastlines. Tidal stream energy leads wave energy conversion and the other technologies in this ocean race. This is the first time that the sector has been specifically monitored for a regular EurObserv'ER theme-based barometer