Concentrating Solar Power (CSP) plants have demonstrated the potential to reduce use of fossil fuels to generate electricity. Yet there are limits to the amount of instantaneous renewables penetration due their intermittency. CSP plants coupled with thermal energy storage can reduce solar power intermittency during the day and maintain power output for several hours into the night. This paper describes a CSP plant with storage that uses mixed ionic-electronic conducting metal oxide particles as both the heat transfer and thermal energy storage media. Thermodynamic and economic analyses are reported for a new design of a 4.6 MWe system using solar resource data from Johannesburg, South Africa. A cost comparison is made to local grid power prices to provide a case study for implementing the technology in emerging markets and developing countries. Demonstrated potential reductions in the cost of electricity and peak grid network loading are shown. Results and analyses are contrasted using system-wide metrics, subsystem metrics, and component-level metrics to inform design decisions that increase the societal impact of the sustainable energy system. The levelized cost of electricity produced by the CSP plant is 12 U.S. cents/kW, lower than the average 19 U.S. cents/kWh unsubsidized cost of electricity in sub-Saharan Africa. This work demonstrates the opportunity for a large-scale, renewable, low-cost, and reliable alternative to existing grid power.