Domestic Material Content in Molten-Salt Concentrating Solar Power Plants

Abstract

This study lists material composition data for two concentrating solar power (CSP) plant designs: a molten-salt power tower and a hypothetical parabolic trough plant, both of which employ a molten salt for the heat transfer fluid (HTF) and thermal storage media. The two designs have equivalent generating and thermal energy storage capacities. The material content of the salt-HTF trough plant was approximately 25% lower than a comparably sized conventional oil-HTF parabolic trough plant. The significant reduction in oil, salt, metal, and insulation mass by switching to a salt-HTF design is expected to reduce the capital cost and LCOE for the parabolic trough system. The report relies primarily on data generated through two prior studies undertaken with WorleyParsons Group that estimated the material content of a molten-salt power tower [1] and oil-HTF parabolic trough plants [2]. New analysis is provided with regard to the material composition of the power tower solar field and the sizing of a salt-HTF trough solar field and HTF system. The overall embodied mass of the salt-HTF trough plant was slightly below that of the salt tower design. The similarity in the total mass of the two designs, combined with the inherent similarity in how the two plants would operate, suggests that salt-HTF trough plants could be competitive with molten-salt power towers if the technical hurdles of deploying salt in the solar field can be overcome. The potential cost and complexity of freeze protection and freeze recovery technology are viewed as having the greatest impact on the viability of salt-HTF troughs. The development of acceptable flexible connections that are compatible with molten salt has also been a challenge. CSP plants are composed mainly of steel, glass, concrete and aggregate materials, which are abundantly available from domestic sources. This is true for most locations in the world where CSP plants might be deployed and is an attractive attribute of the technology with regards to its impact on the local economy. In the U.S., we estimate that 90% by mass and 79% by value of the commodity materials utilized in a CSP plant can be supplied by domestic sources.

On the Path to SunShot. Emerging Opportunities and Challenges in U.S. Solar Manufacturing

“…Relatively few comprehensive data exist regarding the CSP supply chain, especially with respect to producers of specialty CSP components (e.g., receiver tubes, mirrors, reflective films). However, recent work by Turchi et al (2015) has addressed and improved this information gap, documenting the nature, content, and quantity of materials required for typical CSP plants. We highlight this work here and in Section 3.1.3.…”

Parabolic Trough Collector Cost Update for the System Advisor Model (SAM)

“…The ATS heliostat design was also used as the baseline in DOE's 2010 Power Tower Roadmap (Kolb et al 2011). In November 2013, NREL provided DOE with an update to the estimated cost of a molten-salt power tower that included a cost estimate for BrightSource Energy's LH-2.2 heliostat design that is deployed at the Ivanpah Solar Electric Generating System (C. S. Turchi et al 2015).…”

“…The activity in parabolic trough projects indicates that this technology is still active in the marketplace and has benefited from design improvements and cost reductions that warrant an update within NREL's and DOE's cost analysis. Furthermore, the potential of deploying molten salt as the solar field HTF and TES media would allow troughs to more effectively compete with power tower systems (C. S. Turchi et al 2015).…”

“…A key tool in the analysis has been a suite of software tools called Design for Manufacture and Assembly (DFMA), from Boothroyd Dewhurst. This tool was used in a previous NREL analysis from which the installed cost of a state-of-the-art commercial heliostat design was derived (C. S. Turchi et al 2015).…”

“…Most of the changes adjust costs given in (C. S. Turchi and Heath 2013) to 2015. The exception is the heliostat cost, which is updated from 2013 see (C. S. Turchi et al 2015) to 2015. It is interesting, but merely coincidental, that the 2015 heliostat field cost and the 2015 parabolic trough solar field costs are both $170/m 2 .…”