The production of solar thermal power on a continuous, 24-h basis is possible by applying thermochemical energy storage. An international group of industrial and academic partners is studying such a base-load solar power plant concept, where the reversible thermo-catalytic ammonia reaction serves as the energy vector between supply and demand. Early results confirm the technical soundness of the concept using conventional technology, equipment and materials, and indicate also the potential for economic viability. A first-of-a-kind, solar-only demonstration power plant with a net capacity of 10 MWe would require a capital investment of the order of AUD 180 million and operate with a net solar-to-electric conversion efficiency of 18% and a capacity factor of 80%. This would result in levelised electricity costs of less than AUD 0.25 per kWh.