Emerson Process Management has been awarded a contract to apply its Ovation expert control system at the Crescent Dunes Solar Energy Project near Tonopah, Nevada. When it comes online at the end of 2013, this 110-MW concentrated solar power (CSP) project will be the first commercial-scale solar facility in the U.S. to generate power from solar energy that is captured and stored in liquid molten salt.

The project, which is being developed by Tonopah Solar Energy LLC, an affiliate of SolarReserve LLC, is expected to produce enough clean, renewable electricity to power more than 75,000 homes during peak electricity demand.

The contract was awarded by Cobra Thermosolar Plants Inc., who is performing engineering, procurement and construction of the whole Tonopah Solar Energy Project. The Crescent Dunes facility will utilize SolarReserve's CSP technology, with a central receiver tower and integrated energy storage technology that was developed by Pratt and Whitney Rocketdyne.

The facility's 10,500 mirror assemblies will focus the sun's energy to a receiver that sits atop a 540-foot tower where it will heat the liquid molten salt. The molten salt will flow from the "cold" storage tank, up the tower where it circulates through the receiver and is heated by the sun's energy from 500 degrees Fahrenheit to 1050 degrees.

The molten salt then flows down the tower to the "hot" storage tank, where the thermal energy will then be used to produce steam to power a standard steam turbine, which then generates electricity. Excess thermal energy will be stored in the molten salt.

Through a licensing agreement between Pratt and Whitney Rocketdyne and SolarReserve, Pratt and Whitney Rocketdyne will engineer proprietary logic that enables Emerson's Ovation technology to directly control the circuit and heating process of the molten salt system. In addition, the Ovation system will directly control the water/steam cycle, as well as auxiliaries, including heat recovery superheater and reheater, generator breaker control, and raw water pretreatment and chemical dosing.

The control system will provide supervisory control of the mirrors by interfacing with the Heliostat Field Control System, as well as interface to the turbine control system. In all, the Ovation system will manage 14,000 hard and soft I/O points. An important consideration in the selection of Emerson was the robust diagnostic capabilities offered by its AMS Suite predictive maintenance software.

AMS Suite will provide online access to instrument and valve diagnostics, and automatic documentation of field device maintenance information - all contributing to ongoing efficiency at the solar plant. It will also be used to streamline device configuration and commissioning.

"This is a truly innovative project that will be an important source of clean, reliable electricity," said Bob Yeager, president of Emerson Process Management's Power and Water Solutions. "By providing integrated control of major equipment and processes, our Ovation system and the predictive intelligence of AMS Suite will play a key role in the smooth, efficient operation of this noteworthy solar project."