Spanish concentrating solar power (CSP) specialist Torresol is advancing plans for four new power-tower projects, including two record-sized facilities in Abu Dhabi, Recharge can reveal.
In May, Torresol — which is 60%-owned by Spanish engineering firm Sener and 40% by Masdar — commissioned the 19.9MW Gemasolar, the world’s first commercial-scale power-tower project to incorporate molten-salt storage.
Torresol is putting the finishing touches to the Valle 1 and 2 projects — both rated at 50MW and employing parabolic-trough technology — and it has a licence to begin selling electricity to the Spanish grid from the beginning of next year.
The company has four power-tower projects under development — two in Spain and two in Abu Dhabi — that would dwarf any such projects in existence, according to technical director Santiago Arias. It is also developing the parabolic-trough Valle 3.
The Abu Dhabi projects are likely to be built first, given the current cap on new Spanish CSP projects, Arias says.
Abu Dhabi is building its first CSP plant — the 100MW parabolic trough Shams 1 — in partnership with oil giant Total and Torresol’s Spanish rival Abengoa. But Arias says the next CSP projects will almost certainly be based on power-tower technology.
Emirati officials are due to visit Gemasolar in the next few weeks, when a decision may be clinched unofficially, Arias says.
Future solar projects in Abu Dhabi are likely to be opened to a bidding process. But given Torresol’s experience at Gemasolar — and the fact that it is partially owned by Masdar — it will be seen as the strong favourite.
The rated capacity of a power-tower project refers to the size of the steam turbine, rather than the thermal capacity of the solar receiver. Gemasolar employs a 19.9MW Siemens turbine, although the thermal capacity of its receiver is 120MW.
Abu Dhabi’s first powertower project is likely to use a receiver with a thermal capacity of 240MW, and a steam turbine rated at 35MW or 70MW, Arias says.
The lower capacity would allow the plant to generate electricity all night, thanks to its molten-salt tanks, while the latter would only allow five hours of production after the sun goes down.
However, given Abu Dhabi’s huge electricity demand during the day, it is less interested in night-time generation than the Spanish grid operator, Arias says.