Complex Made Simple

ALSOLEN: Fresnel mirror solar power plants providing utilities

ALSOLEN is a French designer and manufacturer of concentrating solar power plants. The company will exhibit its products at the WFES & IWS tradeshow held in Abu Dhabi from January 19th to 22nd, 2015. At its booth (n°8102, French Pavilion), it will display its technology and expertise to local professionals, in a bid to position itself on the Middle-Eastern market.

ALSOLEN acts as an Engineering Procurement and Construction (EPC) company in the field of solar power plants: it handles overall project engineering and performs case studies for the installation, manufacture, materials and components procurement, construction and turnkey completion of the entire facility.

ALSOLEN®’s product is a thermodynamic power plant using Fresnel mirror technology to concentrate sun raylights. Reflectors supporting self mechanically curved plane mirrors are lined up horizontally. By spinning simultaneously, the reflectors will concentrate sunlight into a line absorber containing thermal oil, the heat-transfer liquid used by ALSOLEN. This thermal oil is heated to 300°C, and the produced heat is then transferred via an exchanger to an Organic Rankine Cycle featuring a turbo-alternator that produces electric power. This technique is enjoying increased popularity, for the mirrors actually cost less than those used in parabolic reflectors.

ALSOLEN® concentrating solar power plants include thermal energy storage. Directly connected to the solar field, thermal storage will accumulate heat which is to be used later, in the evening, to continue producing energy. The basic, sturdy design thus makes it possible to size the storage capacity so as to recover the energy for a few hours in the evening, or even for the entire night.

ALSOLEN® concentrating solar power plants can simultaneously deliver a range of services: producing electricity up to 20MWe; supplying heat (up to 100MWth) from the solar field via exchangers, with a temperature adjustable to 300°C; producing cold or ice through an absorption cycle (several hundred kW); producing fresh water by desalinating seawater or brackish water (several hundred cubic metres daily).

ALSOLEN installations are especially suitable for off-grid settings, and they provide very low operating costs since no fossil energy is used. The technology used has been chosen in such a way as to reduce risks to Man and to the environment.

Other positive features in ALSOLEN power plants:

-Generates controllable and predictable energy
-Fast response time; the plant may be started up / shut down several times in the same day
-A preference for sturdy techniques: mirrors, light metal structures with low wind drag, heat-transfer fluid operating under atmospheric pressure, direct storage of heat-transfer fluid under the same pressure, electricity produced by an organic rankine cycle that spares the turbine’s life cycle
-Long-lasting components that make ALSOLEN power plants particularly suitable for semi-arid climates
-Low water requirements for cleaning the mirrors, thanks to a cleaning robot designed by ALSOLEN.

Lastly, the originality of ALSOLEN solar thermal power plants stems from their simple design, allowing for much of the manufacture to take place on the installation site (using a mobile factory), as well as for the possibility of forming and training a local team for construction, operation and maintenance; this design also fosters high performance, reduced and controlled maintenance, with no compromise in combined performance or the facility’s life cycle (25 years or more).

All of the development work behind ALSOLEN solar power plants was the result of a collaboration with the CEA LITEN (Atomic Energy Commission’s Innovation Laboratory for New Energy Technology), one of Europe’s foremost research centres in new energy technology.