1. Energy

Renewable energies meet an energy market that is characterized by an energy demand or rather an exergy demand, a supply by energy carriers and disposal of end products such as carbon dioxide (\(C{O}_{2}\)). Energy supply must satisfy the worldwide population growth as well as the increasing per capita energy consumption and this simultaneously without excessive consumption of resources. The potential of regenerative energies thus depends essentially on their properties, with which they can meet the market characteristics. The profile of the energy demand, its follow-up and production costs as well as the boundary conditions determine the energy market and thus define the framework conditions for the development of regenerative energy sources, which in the future must increasingly satisfy the aspects of sustainability and resource efficiency. This chapter sheds light on these aspects, introduces key terms and discusses in particular the energy market environment in which thermal solar energy operates and finally introduces the concept of sector coupling.