The Value of CSP with Thermal Energy Storage in Providing Grid Stability

AbstractCSP plants both with and without thermal energy storage are unique renewable resources that provide clean electric power and a range of operational capabilities to support continued reliability of electric power systems. Utilizing stored thermal energy storage to operate a conventional synchronous generator, CSP plants with thermal energy storage can support power and provide ancillary services including voltage support, frequency response, regulation and spinning reserves, and ramping serves – services that would otherwise be provided, at least in part, by conventional fossil-fuel generation.By being available during peak demand in sunlight hours and providing the capability to shift energy to other hours, the addition of thermal energy storage to CSP plants improves their contribution to resource adequacy, or capacity requirements, especially as solar penetration increases. This makes CSP an ideal complement to support greater adaption of intermittent resources such as wind and PV.To make procurement decisions that include a balance of both solar PV and CSP, utilities need to see reasonable estimates of quantifiable economic benefits. In simulations of the California power system, recent studies by the Lawrence Berkeley National Labs (LBNL) found that the comparative value of CSP with storage increases as the amount of solar on the grid increases. If CSP with six hours of storage and PV with no storage were each providing five percent of the grid's power, CSP power would have an additional value of $19/MWh (1.9¢/kWh). At grid penetrations of 10 percent each, CSP power would be worth an additional $35/MWh (3.5¢/kWh). The added value results from a calculation of grid integration costs and market benefits. The author will outline how CSP with storage provides grid stability and its corresponding value to utilities