The calculation of the angle between the day-night line on the Earth’s surface, a terminator, and the meridian at a given point, at dawn or at sunset, can easily be performed either by means of flat geometry or, for those familiarized with astronomy, through formulae for the Sun’s azimuth and elevation, both derived from spherical trigonometry. The two procedures are compared. An auxiliary angle obtained in the process of derivation via planar geometry becomes useful to represent the daylight map on a terrestrial planisphere.

This study analyzes the impact of using freely accessible generative AI in the evaluation of students in the Master's Program in Renewable Energies at Universidad Europea de Canarias, with the aim of proposing strategies to ensure that students maintain the necessary knowledge and technical skills. The case study focused on the "Renewable Energy Startups" module, worth 6 ECTS, where students completed practical activities with the assistance of AI tools.The evaluation of AI-generated results was conducted using the same rubric applied in a previous edition, when these tools were not yet available. Additionally, the AI-generated responses to exam questions based on the official syllabus were analyzed, and the time spent was compared with the minimum times outlined in the university's study plan.The findings show that, while AI can reduce the time needed to complete tasks, it is essential to redesign activities to integrate AI in an ethical and effective way. When approached correctly, AI can become a tool that enhances learning, improving students' technical skills without compromising the depth of knowledge.

In this paper, we present the simplest possible method for the precise determination of solar noon in mean solar time, based only on the value of the equation of time corresponding to a predetermined time for the observer, constant throughout the year. This represents a revolutionary simplification of the appendix of the universally known SPA (Solar Position Algorithm, NREL) regarding solar noon. Given that the proposed simple method does not entail a significant loss of precision, it is especially useful for university students or postgraduate students in photovoltaic/solar thermal energy or developers who wish to quickly calculate solar noon or create their own software for analysis or research. In addition, an interpolative procedure is presented to further enhance the precision of the method, although such improvement will not be necessary in the majority of cases.