Solarthermal Plants and Processes for Power and Hydrogen Production
Solar towers are capable of providing high temperature heat to drive either a power block for electricity production or endothermal chemical reactions like those needed to produce hydrogen from water. Technologies for solar thermal electricity production are already very advanced. The current focus of development of concentrated solar power (CSP) is rather on reduction of levelized electricity cost. One key to that is dispatchability through integration of storage. The solar field is optimally sized to charge the thermal storage for later dispatch. Storage capability is extended, which maximizes the amount of energy to be sold and reduces the cost significantly. The ability of CSP to decouple the collection of energy from the production of electricity is a key attribute for further market penetration.
Solar thermo-chemical hydrogen production processes like thermochemical cycles and high temperature electrolysis are still under development. Whereas materials development, process control, heat recovery and smart reactor designs are the most important R&D tasks of many groups, some of the technologies already have reached demonstration phase in a range of 100 kW to 1 MW thermal power. Key elements of the process are being validated on solar towers. Two main routes of processes are thermochemical cycles based on the one hand on metal oxides and on the other hand on sulfur oxides. Those processes allow a flexible operation and use in terms of the product portfolio. Hydrogen production can be integrated with the production of various chemical commodities.