We live in a critical moment for humanity in which energy consumption is growing as the population grows, while fossil fuel resources are diminishing. It is time to bet on the search for renewable energy sources. Here arises, as researchers, the challenge of making these sources efficient and adapting them to the real demand. If we were able to harness all the solar energy that our planet receives, it would be enough to supply our current demand. And here we come into play as engineers, physicists and of course! Mathematicians. On the one hand, regarding the production of renewable electrical energy, one of the main lines of research that we develop at the Energy Optimization, Thermodynamics and Statistical Physics Group of the University of Salamanca is the simulation of Concentrated Solar thermal Power (CSP) such as central tower plants, analyzing possible aspects to improve the efficiency of the subsystems involved. And, on the other hand, to try to adapt the production to the demand, to study different aspects of thermal storage. All these processes are simulated by means of different programs such as Mathematica, Python, Matlab, etc. And, of course, mathematical tools such as analytical and numerical integrals, nonlinear equation solving, differential equation, interpolations, multiobjective optimization, etc., are used for this purpose. Let’s see how mathematics becomes a magic wand that transforms this desire to harness the energy coming from the sun into a reality.