Abengoa’s PS20 solar plant, the largest commercial solar tower plant in the world

The Chairman of Abengoa, Felipe Benjumea, explained the functioning and the advantages of tower technology, a mature solution that offers the most efficient performance compared to other similar technologies, by concentrating solar radiation onto a single spot.

During his speech, Abengoa’s Chairman pointed out that the plant’s operations "are based on generating electricity by obtaining heat from solar radiation. More than 1,000 mirrors, each one 120 square metres in size, placed at the base of the tower, track the sun just like sunflowers".

The 20 megawatts of power produces enough clean energy to supply 10,000 homes, preventing the emission of approximately 12,000 tonnes of CO2 into the atmosphere per annum. Felipe Benjumea added that "energy in the 21st century has to be clean with no greenhouse gas emissions; competitive, internalising all costs, including from the CO2; and storable. These three conditions have all been fulfilled here and we believe that this is the real future for today, a possible future".

The Solúcar Platform also houses a research centre that develops new photovoltaic and thermal technologies, which employs more than 70 scientists and engineers. Thanks to this centre, Spain and Europe are at the forefront of new technologies, which are revolutionising the possibilities for generating electricity from the sun.

Abengoa is a technology company that applies innovative solutions to sustainable development in the infrastructures, environment and energy sectors. It is public listed company and its five business groups of Solar Energy, Bioenergy, Environmental Services, Information Technology, and Industrial Engineering and Construction operate in more than 70 countries.

Concentrating Solar Power Power Tower

Power tower technology is considered to be at medium maturity within concentrated solar power technology. The first commercial power tower plant using power tower technology was installed by Abengoa Solar and it is successfully celebrating its 2 years in operation.
The second generation, Abengoa Solar-built, like the first, recently began operational start-up, and the third is based on the technology used in high-temperature demonstration plants.

Introduction to Technology

On tower systems, a heliostat field comprised of movable mirrors, is oriented according to the solar position in order to reflect the solar radiation concentrating it up to 600 times on a receptor located on the upper part of the tower. This heat is transferred to a fluid with the purpose of generating steam that expands on a turbine that is coupled to a generator to produce electricity.

Tower technology operation is based on three main features: heliostats, receptor, and tower.

* Heliostats have the function to capture solar radiation and direct it to the receiver. They are composed of a reflective surface, a supporting structure and mechanisms used to orientate them, following the sun’s movement (which involves the necessary systems for the heliostat movement as well as control systems). The most used reflective surfaces today are glass mirrors.

The receiver which transfers received heat to an operating fluid (which could be water, molten salts, etc.). This fluid is in charge of transmitting hear to other parts of the C.S.P. plant, generally to a water deposit, obtaining high temperature steam to produce electricity through the action of a turbine. Latest advances and research are centered to obtain high temperature towers, with heat transporting fluids, such as air, salts, etc.

The tower acts as support for the receiver which should be located at a certain height above the heliostats level to avoid, or at least reduce, shades and blockings.