The disclosed technology includes converting solar energy to thermal energy and delivering heat for use in a process. A representative method includes transferring solar energy to a working fluid and transferring energy from the working fluid to a heating element positioned inside a heating well. The heating well contains a thermal energy storage substance (TESS). A controller controls the heating element, which is in thermal communication with the TESS. In some embodiments, the TESS releases and absorbs heat as latent heat, which reduces temperature variation in heat exchange between the heating well and the formation surrounding the heating well. In such embodiments, the TESS is positioned between the heating element and an outer casing of the heating well. In addition to heating wells, the disclosed technology can be applied to other processes involving heat delivery.
