Estimating the Value of Utility-Scale Solar Technologies in California Under a 40% Renewable Portfolio Standard

Research output: NRELTechnical Report


Concentrating solar power with thermal energy storage (CSP-TES) is a unique source of solar energy in that its output can be shifted over time. The ability of CSP-TES to be a flexible source of generation may be particularly valuable in regions with high overall penetration of solar energy, such as the state of California. California's Renewable Portfolio Standard (RPS) requires the state toincrease generation from eligible renewable energy resources to reach 33% of retail electricity sales by 2020. Beyond 2020, California targets a further reduction in greenhouse gas emissions. To help reach this goal, current California governor Jerry Brown has stated that a higher 40% RPS might be reachable in the near term. The levelized cost of energy is generally emphasized when assessing theeconomic viability of renewable energy systems implemented to achieve the RPS. However, the operational and capacity benefits of such systems are often ignored, which can lead to incorrect economic comparisons between CSP-TES and variable renewable generation technologies such as solar photovoltaics (PV). Here we evaluate a 40% RPS scenario in a California grid model with PV or CSP-TES providingthe last 1% of RPS energy. We compare the technical and economic implications of integrating either solar technology under several sensitivities, finding that the ability to displace new conventional thermal generation capacity may be the largest source of value of CSP-TES compared to PV at high solar penetrations.
Original languageAmerican English
Number of pages42
StatePublished - 2014

NREL Publication Number

  • NREL/TP-6A20-61685


  • capacity value
  • concentrating solar power (CSP)
  • production cost modeling
  • thermal energy storage


Dive into the research topics of 'Estimating the Value of Utility-Scale Solar Technologies in California Under a 40% Renewable Portfolio Standard'. Together they form a unique fingerprint.

Cite this