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Spain must reduce its energy consumption by 23% and achieve 100% renewable energy in electricity generation by 2030. This paper presents the current energy scenario en Spain, and the outlooks for different renewable options, with special focus on photovoltaic (PV) solar energy. In 2012, Spain was the number two European country in terms of installed rewnewable energy power. Solar PV technology has the potential to meet Spain's future energy demand and its associated environmental challenges. This paper gives a review of solar energy economy at global scale for both PV and thermal power technologies. The Spanish energy scenario shows actual trends and progress made by solar power. Economic concepts of levelised cost of electricity and grid parity are presented. The financial analysis shows that PV electricity achieves grid parity at a plant profitability rate up to 7.26%. [ABSTRACT FROM AUTHOR]

Abstract: The most widespread support system for renewable-energy-sourced electricity (RES-E) is the feed-in tariff (FIT). FITs can be divided into fixed-FIT and premium systems. The latter type may also include a cap and floor option, turning it into a variable premium system. The cap value (upper limit) aims to avoid windfall profits for the RES-E investor if the electricity price rises quickly, while the floor value (lower limit) ensures minimum revenue, reducing the risk caused by low electricity prices. This paper examines the performance of the variable premium system as established in Spain (hourly-based) and investigates the possibility of alternative novel designs. For this purpose, an analysis was undertaken of the cap & floor system established in Spain based on real market data over a three year period and its performance compared to the fixed premium system (no cap & floor limitations) and two novel cap & floor designs (monthly- and yearly-based). Two other novel alternatives were also considered: daily- and weekly-based. It is shown that the hourly-based cap & floor system did not result in a reduction of the overall RES-E revenue compared to the fixed premium system over the three year period, though revenue was more evenly distributed from year-to-year. The paper concludes that variable premium systems should be based on monthly or yearly cap & floor mechanism as opposed to an hourly one. [Copyright &y& Elsevier]

Abstract: This paper shows the study carried out in a doctoral thesis about windmills in south-east Spain, in the area of Campo de Níjar in the province of Almeria. It intends to pay homage to Spanish windmills as a way of commemorating the fourth centenary of the masterwork of Spanish Literature, ‘Don Quixote’ in which the silhouette of the windmill is a pervading symbol. Wheat milling has been an important factor in the socio-economic development of rural Spain for centuries. The type of mill used depended on the energy resources available, wind or water. In the Campo de Níjar (Almeria, Andalusia, Spain), wind is the principal energy source, and therefore, windmills were widely used, as in other areas of Spain. In this paper, we study the technological conditions of these old windmills, we carry out a wind evaluation of the area, and we calculate the power and momentum of these windmills with a discussion of the results found. [Copyright &y& Elsevier]

The repowering of already installed wind farms is considered one of the most promising and cost-effective short-term strategies to scale-up wind capacity. In this study, we apply Markowitz's mean-variance (MV) portfolio optimization theory to explore alternative repowering actions in Spain. The efficient portfolios – a direct outcome of the MV optimization – offer optimal repowering alternatives to current wind farm generation mixes. They deliver the highest possible average power output (yield) for a given level of supply risk. Different repowering scenarios are considered in this paper that range from a full restructuring of the existing wind generation mix to restricting by certain amounts the percentage of down-/uprating of each reference region. Results show that, depending on the configuration of the MV portfolio optimization problem, hourly fluctuations in the aggregate power supply can be reduced as much as 12–31%, while retaining the current level of energy productivity. In addition, for the level of energy supply risk experienced with the existing portfolio of Spanish wind farms; we can derive more efficient mixes that boost-up productivity by 16–55%. This work aims at providing valuable insight for energy policy-making in the direction of optimally repowering future renewable generation. [ABSTRACT FROM AUTHOR]

Optimal siting of wind farms based on a pre-assessment of the spatiotemporal variability of wind resources is considered a suitable method for reducing fluctuations in the delivered output. In this study, we explore the potential for balancing wind energy generation in the Iberian Peninsula using Principal Component Analysis (PCA). This technique permits the discovery of possibly new promising locations for wind power harvesting and an evaluation of the existing wind farm network in terms of reliability in energy generation. Data input to the PCA consists of hourly wind capacity factor in a 5-km spatial resolution grid covering the entire peninsula. These data are derived from an equivalent wind farm power curve fed by modeled wind speed data from 80 m above ground level. PCA reveals three significant balancing patterns prevailing over the IP, where half of the currently operating wind farms in Spain are placed. Hence, among the many constituents of the existing wind farm network, these spots offer the best opportunity for stable power supply. The paper concludes by making proposals on an optimum wind capacity allocation based on the idea of equally distributing installed power between positive/negative dipoles emerging from balancing principal components. [ABSTRACT FROM AUTHOR]

Abstract: This paper aims at providing scientific evidence of the existence of a high potential of solar energy, not only for the application of flat photovoltaic installations, but also for tracking systems that use concentration, which promise to contribute towards lowering the cost of photovoltaics to the €1/Wp value. It reports results of solar radiation data gathered in Malta (latitude 36°), which represents a central Mediterranean location and compare it to the Region of Valladolid (latitude 42°), within continental Spain to the west of the Mediterranean region. The availability of direct normal radiation is quite good for both sites and could support the building of concentrated systems in the region. A 5-year cumulative annual global solar radiation on a horizontal surface was found to be 1693 and 1841 kWh/m²/day for Valladolid (Spain) and Marsaxlokk (Malta), respectively. Studies showed that Marsaxlokk had a greater normal direct solar potential than Valladolid, but with lower annual variance. Daily analyses showed that Marsaxlokk had more sunny days, similar frequency of partly cloudy days and much lower overcast days than Valladolid. Seasonal analysis showed that Valladolid had less sunshine in autumn and winter but similar availability as Marsaxlokk in spring and summer. A number of correlations between the Clearness Index and the Diffuse Fraction were also made. Such correlations are very useful in estimating past missing data and forecasting future solar availability. [Copyright &y& Elsevier]

Abstract: This article presents a detailed study, of the Manchegan windmill. This type of windmill is a central symbol in the story of Don Quijote de la Mancha, by Cervantes, which this year celebrates its 4th centenary, and to which this article pays homage. There exist no publications dealing with the technical aspects of these windmills. Studies have been carried out on windmills in the south of Spain, but no comparison has been made between the two types of windmill. This paper studies the technological conditions of the original Manchegan windmills. We carry out a wind evaluation of the region, calculate the power and momentum of the windmills and discuss the results obtained with a comparison with the type of Southern Spanish windmill. [Copyright &y& Elsevier]