Plant Cost and Performance Projections Methodology

When comparing the ATB projections with other projections, note that there are major differences in technology assumptions, radiation conditions, field sizes, storage configurations, and other factors.

The Low ATB projection is based on the SunShot Vision Study (DOE (2012); Mehos et al. (2016)) and has been vetted with solar industry representatives.

Projections of future utility-scale CSP plant CAPEX and O&M are based on three different technology cost scenarios were developed for scenario modeling as bounding levels:

• Constant cost
  • Modeled as molten-salt (sodium nitrate/potassium nitrate, aka, solar salt) power tower with direct two-tank TES combined with a steam-Rankine power cycle running at 574° C and 41.2% gross efficiency in 2016
  • Costs stay the same from the 2020 estimate through 2050, consistent with ATB renewable energy technologies
• Mid cost
  • Based on published projections that highlight an overall CSP CAPEX reduction of 25% by 2030 compared to 2015 costs, and which represent a potential median compared to other published CSP projections until 2050 (Feldman et al. 2016; IRENA 2016)
  • Gradual reductions in heliostat and power system cost due to greater deployment volume assumed for 2020 and onwards based on current state of industry
  • CAPEX and O&M both drop by 25% by 2030, relative to 2015 costs
  • A further 20% overall CAPEX decrease is assumed from 2030 to 2050. All three components of the CSP CAPEX (the turbine, storage, and the solar field), decrease proportionately by 20% from 2030 to 2050.
• Low cost
  • Significant reductions in heliostat and power system cost due to greater deployment volume and R&D are used for 2020; the plant was modeled as an advanced molten-salt power tower with direct two-tank TES combined with a power cycle running at 700° C and 55% gross efficiency in 2030 (Mehos et al. (2017)).
  • SunShot CAPEX and O&M targets are approximately met in 2030, including new high-efficiency power cycles and low-cost heliostats.
  • A further 20% overall CAPEX decrease is assumed from 2030 to 2050 based on potential deployment in the United States. The 20% decrease in overall CSP CAPEX is split over the three components: the turbine, storage, and the solar field. It can be expected that greater cost reductions could be achieved for the power block/turbine and the solar field than for the storage.