Solar and Wind Feasibility Technologies (SWIFT)

by M.I. Dieste-Velasco

https://doi.org/10.1016/j.aej.2024.01.054

Fault detection in analog circuits is of great importance to predict the correct operation of the circuit. For this purpose, soft computing techniques such as those based on the application of fuzzy inference systems stand out. However, given the large variability that can exist in analog circuits due to component tolerance, the initial fuzzy inference system (FIS) may not be able to accurately diagnose the different hard faults. This study presents a methodology to diagnose and detect the faults that can occur in analog circuits, which is based on the development of a FIS, starting from a specific fault situation in the analog circuit, and subsequently on the optimization of the membership functions using an evolutionary algorithm so that the adjusted FIS can classify and predict different failure situations. To this end, the application of optimization techniques based on particle swarm optimization (PSO) will be analyzed to develop a FIS capable of predicting different faults. In addition, pattern search algorithm will also be analyzed. A Sallen-Key band-pass filter and a single stage of a small-signal amplifier are used as test circuits. The proposed methodology shows that it is possible to accurately predict the faults that could arise in the circuits under study.

by E. Garrachón-Gómez, I. García, A. García-Rodríguez, S. García-Rodríguez, C. Alonso-Tristán

https://doi.org/10.1016/j.compag.2023.108523

Agriculture is by far the most important economic activity in the Spanish autonomous region of Castilla y León. Numerous factors influence crop development but one of the most related variables to the photosynthetic process is Photosynthetically Active Radiation (PAR). Estimating Intercepted Photosynthetically Active Radiation (IPAR) in different crops through the Beer-Lambert law could be a relevant factor in crop season planning by enabling photosynthesis monitoring. The Beer-Lambert Law is applied in this study to the data for almost 2 million hectares of wheat, barley, and maize cultivated in Castilla y León in 2021. The fourteen-year data set of Global Horizontal Irradiance (GHI) used to calculate the monthly PAR data in the region was collected at 93 meteorological stations (46 in Castilla y León and 47 in neighboring Spanish and Portuguese regions). Two previously published global calibrated models were employed to calculate the PAR, with a relative Root Mean Square Error (rRMSE) below 6%, for the measured daily mean values of PAR in Burgos. Processing the various NASA Terra and Aqua satellite images yielded the monthly Leaf Area Index (LAI) and the literature review provided the light extinction coefficient (k). The Geographic Information System (GIS) facilitated visualization of IPAR estimates for the three cereal crops in all months of its growing season. Wheat and barley reach their IPAR peaks in June and July, while maize peaks in July and August. In addition, the fraction of Intercepted Photosynthetically Active Radiation (fIPAR) was calculated in different provinces to assess PAR interception for each cereal at different growing stages. In June, almost 50% of the wheat area in Burgos, Palencia and Soria displayed fIPAR values exceeding 45% while in the case of barley only the province of Burgos reached these percentages of area and.fIPAR.

by M.I. Dieste-Velasco, I. García-Ruiz, D. González-Peña,  C.  Alonso-Tristán

https://doi.org/10.1016/j.renene.2024.120926

The use of daylight in buildings contributes to energy savings while significantly improving visual comfort and well-being. It is therefore very important to be able to quantify illuminance to take advantage of daylight. Although several models have been proposed in recent years to determine global and diffuse illuminance, the same may not be said of direct solar illuminance, which situates this study in an area of noteworthy scientific and technological interest. Two luminous efficacy models for clear sky conditions are proposed and the results of benchmarking with previous models from the literature are presented. Data collected in Burgos (Spain) were analyzed. Specifically, eight previous models for the prediction of direct illuminance were compared with our two new models. The two new models predicted illuminance more accurately than most of the classic models. Specifically, running the models on the training data yielded Root Mean Square Error (RMSE) values of 2.58 % and 2.76 % for the first and the second model, respectively. Likewise, the test data yielded RMSE values of 3.31 % and 3.49 %, and the Mean Bias Error values with the training data were 0.06 % and 0.11 %, respectively. The models achieved high accuracy levels with both the training and the test data sets.

by D.Granados-López, D. Gatt, C. Yousif , M. Díez-Mediavilla and C. Alonso-Tristán

https://doi.org/10.1016/j.egyr.2022.12.085

The 2018/844 Energy Performance of Buildings Directive (EU) has widened the scope of appropriate design of buildings from a pure energy performance and carbon emissions perspective to a wider scope that includes indoor comfort, and indoor air quality among others. To this effect, external parameters, especially solar energy, have a strong impact on the energy performance of buildings in Mediterranean regions, which requires careful consideration when it comes to benefiting from natural lighting while avoiding solar overheating. This paper addresses the considerations of natural lighting in the deep renovation of a housing block in the Mediterranean climate of the Republic of Malta, comparing some of the usual illuminance ranges to achieve optimal conditions based on international recommendations. DesignBuilder v7.0.0.102 has been the selected software to model the building that has been calibrated through experimental measurements. The model enabled the natural lighting conditions in the building evaluated and the effectiveness of suggested improvements to be determined. Results pointed out that the building under study satisfies the international standards about the prevention of visual discomfort only. Increasing the size of windows in identified zones, especially the first floor, was found to help improve other natural lighting characteristics. One of the proposed designs (Model 6) that replaces single-glazed with double-glazed windows that include an external spectrally-selective coating would significantly improve access to natural light bringing the building closer to the recommended levels of Annual Sunlight Exposure and reducing artificial lighting usage by up to five times. The relocation of room spaces could also reduce the use of artificial lighting.