Novel cascaded power plant process and method for providing reversibly usable hydrogen carriers in such a power plant process

A method for providing energy in a power plant process, having the following steps:

• introducing a starting material into a reaction area, the starting material comprising one or more of the following components:
• sand, bauxite containing silicon dioxide, quartz, gneiss, mica, granite, slate;
• providing a primary energy provider to start a reaction, in which the starting material is heated and silicon is produced from the starting material;
• using the silicon in a first partial reaction, which runs exothermically;
• using said heat as a secondary energy, in order to replace the primary energy provider when heating the starting material and/or to supply at least one further partial reaction or series of partial reactions with the required energy, at the end of which a silicon product is provided.