THE POWER TOWER AND PRICE

Central receiver technologies power CSP toward grid parity
Bob Moser, 26 May 2011 (CSP Today)

"With a DOE loan guarantee offer now in hand for US$737 million, SolarReserve's 110-megawatt Crescent Dunes solar project may serve as a breakthrough example for molten salt receiver technology, and accelerate CSP's competitiveness with cheaper renewable options in the US.

"Construction should start… within the next few months in Tonopah, Nev., with operations set to begin in late 2013. It will be the world's largest molten salt tower project, and power 75,000 homes with electricity generation day and night. The electricity generated has been contracted by NV Energy under a long-term purchase agreement approved last year…"

schematic of solar power tower + storage (click to enlarge)

[Brett Prior, senior analyst, GTM Research/GreenTech Media:] “In my analysis, the most cost-effective dollars per kilowatt hour option is power tower with storage, and that is what SolarReserve is working on…CSP generally is having a tough time competing with PV on cost per kilowatt hour…It's more cost-efficient, but the only way this type of technology system is going to succeed is with a couple demonstration projects going forward to work the kinks out, get the learning going and their costs down, so they can really ramp up and make this mainstream.”

"SolarReserve's molten salt concentrating technology had already been successfully tested in California in a DOE-sponsored 10 MW pilot project in the late 1990s. With a growing number of molten salt central receiver projects being planned around the world, this technology is slowly being established…"

eSolar's 5MW prototype power tower plant (click to enlarge)

"SolarReserve believes molten salt central receiver towers offer benefits of base load power generation by having its storage capability part of the inherent system design, as opposed to a storage system simply attached to the CSP base, which will require extra capital cost and lose efficiency with heat movement from a collection medium, like therminol, to a storage medium like molten salt…

"Operational advantages exist as well for a central tower design…because molten salt stored in storage tanks when the central receiver isn't in use lets the system drain into those storage tanks. It allows the operator to avoid any complications with using molten salt as the working fluid…"