A compilation of innovative educational activities to work on concepts related to the production of electrical energy is presented. To approach the real-life secondary education curriculum, they are grouped to be performed during a week denominated Renewable Energy Week: an educational proposal aimed to promote the respect for the environment through the insight on Sustainable Development Goals (SDG) and renewable energy sources. The students would build and perform low-cost experiments so as to deeply understand the essence of energetic transformations, as well as electricity generation. Learning by discovery, collaborative learning and experimentation, are the methodological pillars that characterize Renewable Energy Week, since they have been proven to be efficient methodologies to promote students’ learning. Innovative techniques for pupils evaluation are employed, including a rubric, Socrative application and a set of sheets regarding experiments. Through this educational proposal, the students are expected to achieve a deep understanding of some key concepts related to electricity and awaken their interest in scientific subjects, making them conscious of the transition to sustainable development that our planet urgently requires. At the same time, this project offers to teachers a series of experiments and innovative activities to work on the SDG in Physics, Chemistry and Technology subjects.

Small-scale hybrid parabolic dish concentrated solar power systems are a promising option to obtain distributed electricity. During the day, solar energy is used to produce electricity, and the absence of sunlight can be overwhelmed with fuel combustion. This study presents a thermo-economic survey for a hybridized power plant in different regions of Spain, considering the local climatic conditions. The developed model considers the instant solar irradiance and ambient temperature dynamically, providing an estimation of the power output, the associated fuel consumption, and the most relevant pollutant emissions linked to combustion. Hybrid and combustion-only operating modes at selected geographical locations in Spain (with different latitudes, mean solar irradiances, and meteorological conditions) are analyzed. The levelized cost of electricity indicator is estimated as a function of investment, interest rate, maintenance, and fuel consumption actual costs in Spain. Values of about 124 €/MWhe are feasible. Fuel consumption and emissions in hybrid operation can be reduced above 30% with respect to those of the same turbine working in a pure combustion mode. This model shows the potential of hybrid solar dishes to become cost-competitive against non-renewable technologies from the point of view of costs and reduction in gas emission levels in regions with high solar radiation and low water resources.

A hybrid central tower thermo-solar plant working with a gas turbine is simulated by means of an in-house developed model and software. The model considers the integration of all plant subsystems. The calculation of the heliostat solar field efficiency includes the main losses factors as blocking, shadowing, attenuation, interception, and cosine effect. The simulation considers a Brayton cycle for the power unit with irreversibilities in the compressor and turbine, and pressure drops in the heat absorption and extraction processes. A combustion chamber burning natural gas ensures an approximately constant power output. The model is flexible and precise. At the same time it is fast enough to perform sensitivity studies on the efficiency of any subsystem and the overall plant. Thus, it allows for performing a thermo-economic analysis of the plant checking the influence of the main plant design parameters. The focal objective is to analyze the importance on the levelized cost of electricity (LCoE) of the key plant design parameters. The direct influence of parameters from the heliostat field and receiver (as tower height, distance to the first row of heliostats, heliostats size, receiver size and heat losses, etc.) on final LCoE is surveyed. Similarly, parameters from the turbine as pressure ratio, turbine inlet temperature, influence of recuperation and others, are also analyzed. The dimensions of the plant are taken from SOLUGAS prototype near Seville, Spain, although another location with quite different solar conditions in Spain is also considered. LCoE values predicted are about 158 USD/MWh. The analysis concludes that among several parameters surveyed, two of them are key in LCoE predicted values: turbine inlet temperature and solar receiver aperture size.

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