Siemens Energy is to supply an industrial steam turbine for Solar Tres solar tower power plant in Spain.  

The Spanish company Sener will build the solar thermal power plant with a capacity of 19 megawatts (MW) at a site in the vicinity of Seville in Andalusia.

Terming the solar power market as one of the fastest growing power plant markets, Markus Tacke, CEO, Siemens Business Unit Industrial Applications, Steam Turbines, said, "Due to their flexibility, our steam turbines are perfectly suited for deployment in solar power plants to ensure the efficient production of eco-friendly electricity."

In the Solar Tres plant, to be operated by Sener, the sunlight will be bundled by sun-tracking mirrors and reflected directly to a receiver located on top of an approximately 120-meter-high tower. The heliostats will be arranged over a surface area of 320,000 square meters, which is equivalent to the size of more than 40 soccer fields.

According to the company, a unique feature of the Sener project is the use of salt for heat transfer in the interior of the receiver instead of the thermo oil normally used in solar thermal power plants. Bundling of the sunlight produces temperatures of over 850°C at the solar receiver. The salt heated to approximately 565°C flows in a molten state through a heat exchanger, in which sufficient steam is produced to operate a steam turbine-generator.   

For the demonstration plant, Siemens will supply a two-cylinder reheat SST-600 industrial steam turbine, which was specially adapted to meet solar technology requirements. The reheat enhances overall power plant efficiency. As per a concept developed jointly with Sener, the steam turbine is protected from cooling down too much at night and it also significantly shortens the warm-up phase on start-up.