The specialist for process heat and heat transfer, heat 11 from Bielefeld, Germany, has taken into operation three heaters in Andalusia (Spain) for the 50 megawatt (MW) parabolic trough power plant "Los Arenales" near the town of Morón de la Frontera in Andalusia. The heaters are among the key components of the heat transfer system of the power plant. The capacity of the power plant is sufficient to supply approximately 50.000 Spanish households with environmentally friendly electricity.
In this type of solar thermal power plant, the irradiation is focused by parabolic reflectors onto an absorber pipe in which thermal oil circulates as heat transfer medium. The heated oil is used to generate steam by a heat exchanger which generates power via a steam turbine, as in a conventional power plant.
The power plant Arenales has also thermal salt storage systems so that power can be generated also at night. "Hereby an almost 24-hour operation is possible in the summer months - a major advantage over the photovoltaic plants!" explains Stephan Kraus, member of the management at heat 11.
Installer of the power plant and heat 11-customer is Ecolaire S.A. which belongs to the Spanish OHL group. OHL is a group of companies with a turnover of approximately EUR 5 billion which develops and implements infrastructure projects worldwide.
The plants of heat 11 are used, among other things, for heating the heat transfer circuit and for controlled start-up of the power plant before sunrise and have a capacity of 16 MW each. The boilers used for this purpose are about 15 m high and 3,5 m in diameter. The scope of supply includes not only boilers, burners and chimneys, also the required control systems and the supervision of the construction and installation of all three plants.
Heaters for solar thermal power plants are a part of the heat 11 range of products in the field of renewable energies which also includes plants for the production and treatment of heat, electricity and gas from biomass.
About the technology
Solar thermal power plants generate electricity by solar radiation which is converted into thermal energy. Reflectors focus the solar energy onto an “absorber pipe” in which a heat transfer fluid (thermo oil) runs and is heated up. With the hot thermo oil, steam is generated in a power plant block that is utilized, as in conventional power plants, in a turbine to generate power.
Through integration of thermal storage, the solar thermal power plants can generate electricity even after sunset. The so-called “base load capacity” is a major advantage of this technology compared to the photovoltaic or also the wind energy.
Source: heat 11 GmbH & Co. KG