This chapter compares the performance of two solar electricity-generation technologies with complementary energy-storage technologies—concentrating solar power (CSP) with thermal energy storage (TES) and photovoltaic (PV) solar with battery energy storage (BES)—in providing capacity during time periods with high electricity demand. We develop optimisation models, which determine the configuration and hourly operation of the two technologies, and apply the models to a case study that is based on the southwestern United States of America, which is a region that has excellent solar availability. Our models and case study demonstrate that PV with BES is superior to CSP with TES in terms of capital cost and peaking capability. Altogether, our results suggest that solar technologies can help to maintain reliable electricity supply under carbon constraints in regions of the world, such as east Asia, with relatively good solar resource. We conclude this chapter with a discussion of policy and regulatory changes that can help to achieve such an end.