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Nowadays, the photovoltaic technology level development makes it the best option for its building integration as energy supplier. Nevertheless, its aesthetic appearance plays a relevant role because architect requirements go beyond the simple installation of solar devices on terraces. In order to fulfill their requirements, the typical white backsheet uses to be replaced by a black one. This simple change leads to a huge PV module performance reduction. In this work, it has been demonstrated that a suitable material selection allows to fabricate photo voltaic modules with a high architectonic integration, but without power reduction with respect to the most commercial solar devices. The former consists in the replacement of the typical glass front cover and the white backsheet by an antireflective glass and a black backsheet respectively. All the study has been developed on real size photovoltaic modules fabricated in an automatic line. The obtained results determine that those modules where black backsheets are used, suffer a power reduction equal to 8.66 W per fabricated module. Nevertheless, when in addition of the black backsheet an antireflective coating glass is implemented, the resulted PV modules present a more aesthetic presence without a detrimental of their power performance when they are compared to the standard PV modules. Additionally, the fabricated solar devices using the proposed configuration successfully overcome the most common aging tests. Política de acceso abierto tomada de: https://openpolicyfinder.jisc.ac.uk/id/publication/11131

We propose a methodology to price an insurance contract designed to hedge the volumetric risk associated with weather conditions. Our methodology is based on conditional quantile regressions and adapts Value at Risk (VaR) and Expected Shortfall statistics from the literature on financial econometrics. In our empirical application, we use actual daily meteorological and radiation data for 40 European cities in 13 countries, from April 1, 2011, to December 31, 2021, and calculate the value of the annual insurance premium under reasonable assumptions on the technology of the solar panels and expected energy demand. We consider variables such as temperature, wind speed, and precipitation in our calculations. Our results for the different cities in our sample show that due to the nonlinear impact of weather (mainly temperature and precipitation) on the expected generation losses, it is appropriate to use quantile regressions to calculate the VaR of radiation, conditional on weather factors. Our insurance premium calculations also present a high degree of variation across European, which indicates that risk-diversification opportunities of catastrophic risk due to weather conditions faced by insurance companies exist. This variation is explained by different weather conditions, model adjustment, and the average price of electricity.

A volume transmission phase holographic element was designed and constructed to perform as a building integrated photovoltaic concentrator. The holographic lens diffracts light in the spectral bandwidth to which the cell presents the highest sensitivity with a concentration factor of 3.6X. In this way, the cell is protected from overheating because the infrared for which the solar cell is not sensitive is not concentrated. In addition, based on the asymmetric angular selectivity of the volume hologram and based on the linear concentration, only single-axis tracking is needed. The use of the holographic element increases the efficiency of the PV cell by 3% and the fill factor by 8%.

Parabolic reflectors, also known as parabolic troughs, are widely used in solar thermal power plants. This kind of power plants is usually located on desert climates, where the combined action of wind and dust can be of paramount importance. In some cases it becomes necessary to protect these devices from the joined wind and sand action, which is normally accomplished through solid windbreaks. In this paper the results of a wind tunnel test campaign, of a scale parabolic trough row having different windward windbreaks, are reported. The windbreaks herein considered consist of a solid wall with an upper porous fence. Different geometrical configurations, varying the solid wall height and the separation between the parabolic trough row and the windbreak have been considered. From the measured time series, both the mean and peak values of the aerodynamic loads were determined. As it would be expected, mean aerodynamic drag, as well as peak values, decrease as the distance between the windbreak and the parabolic increases, and after a threshold value, such drag loads increase with the distance.

The most successful peer-to-peer networks are based on the concept of supernode, which is an operating point of the network that provides services and advanced functionalities to other nodes. Inspired by this idea, this paper proposes to integrate nodes that provide intelligent advanced services in the future architecture of the electrical grid. Besides facilitating the access to data services such as demand estimations and weather forecasts, these nodes are especially meant to hold virtual environments in which software agents, after being contracted, negotiate on behalf of users in energy markets. This architecture is designed to be compatible with the Energy Interoperation OASIS standard. The capabilities and feasibility of the proposal is demonstrated through realistic experiments based on OpenADR programs, in which users exchange energy by using parallel auction markets. In addition, in order to have the roles of buyer and seller in demand-response programs, thus allowing the creation of markets, a conceptual model based on negative loads and critical loads is provided. The experiments have proven that the proposed architecture facilitates the implementation of advanced distributed management systems in order that smart metering infrastructures, in contrast with traditional agent-based solutions, are released to perform negotiation tasks and access data services, while users gain both autonomy and decision-making capacity. 11 1 2,912 5,746 Q1 Q1 SCIE

Abstract This paper presents the analysis of the performance of a solar cooling facility along one summer season using a commercial single-effect water–lithium bromide absorption chiller aiming at domestic applications. The facility works only with solar energy using flat plate collectors and it is located at Universidad Carlos III de Madrid, Spain. The statistical analysis performed with the gathered data shows the influence of five daily operational variables on the system performance. These variables are solar energy received along the day (H) and the average values, along the operating period of the solar cooling facility (from sunrise to the end of the cold-water production), of the ambient temperature ( T ¯ ), the wind velocity magnitude (V), the wind direction (θ) and the relative humidity (RH). First order correlation functions are given. The analysis of the data allows concluding that the most influential variables on the daily cooling energy produced and the daily averaged solar COP are H, V and θ. The period length of cold-water production is determined mainly by H and T ¯ .

Wind power time series usually show complex dynamics mainly due to non-linearities related to the wind physics and the power transformation process in wind farms. This article provides an approach to the incorporation of observed local variables (wind speed and direction) to model some of these effects by means of statistical models. To this end, a benchmarking between two different families of varying-coefficient models (regime-switching and conditional parametric models) is carried out. The case of the offshore wind farm of Horns Rev in Denmark has been considered. The analysis is focused on one-step ahead forecasting and a time series resolution of 10 min. It has been found that the local wind direction contributes to model some features of the prevailing winds, such as the impact of the wind direction on the wind variability, whereas the non-linearities related to the power transformation process can be introduced by considering the local wind speed. In both cases, conditional parametric models showed a better performance than the one achieved by the regime-switching strategy. The results attained reinforce the idea that each explanatory variable allows the modelling of different underlying effects in the dynamics of wind power time series.