Photo of solar tower at Abengoa Solar's Solucar Complex, Seville, Spain

Solar tower receiver system with natural circulation

Aalborg CSP develops and supplies solar tower receivers and steam producing equipment for saturated and superheated steam. Aalborg CSP carries out project management, quality assurance (QA), design and manufacturing.


The receiver consists of panels made of parallel tubes filled with water or steam that are placed in a high tower delivered by the customer.


Aalborg CSP's receiver system for saturated steam is based on a natural circulation system. This eliminates the use of forced circulation by pumps and increases the total effectiveness of the receiver considerably. The receiver system has high steam purity, a high efficiency and there is a low investment and maintenance cost of the system. The main advantage of the overall system is that the steam is heated directly without any kind of heat transfer fluid (HTF).


Read about Aalborg CSP's projects within solar tower receivers and the CSP technology in general. 


Aalborg CSP can supply:

  • Receiver systems
  • Studies and analyses
  • Calculation of heat balances
  • Calculations according to EN and ASME standards
  • Design and calculation of structural steel
  • Third party approval
  • Manufacturing and delivery world wide
  • Control systems
  • Supervision
  • Commissioning

How solar towers work

Solar power towers generate electric power from sunlight by focusing concentrated solar radiation on a tower mounted steam generator (receiver). The system uses sun-tracking mirrors to reflect the incident sunlight onto the receiver. The receiver converts this concentrated solar energy into saturated steam. The steam is used in a steam turbine to produce electricity.


The steam part can get more effective by extension of a (fired) superheater or a thermal storage system.


Video presenting how Seville in Spain is going to be entirely powered by CSP technology - after the video was made, it has been decided that both parabolic troughs and tower systems will be installed instead of merely towers. Therefore, there will not be nine towers as stated in the video.


Technical information on solar tower receiver systems

The solar tower receiver system is built up with steam drums, receiver panels and interconnecting piping.


The steam generator's steam drum is designed according to the specific standards for steam boilers. Circulation ratio, required steam space, sufficient retention time and sizing of the cyclones and chevrons according to ABMA 92 are all incorporated in our design.


The receiver panels are made of a special alloy in order to resist the intense heat flux from the solar radiation. A special steam injection system secures a safe and fast startup for all components. The natural circulation ensures the most economic operation of the system and secures the highest heat flux per m2 possible. Flex and stress calculations of all elements will be conducted in order to design the hangers and pipe stresses, securing safe and reliable operation for years.


For superheated steam an extra set of receiver panels is to be installed. From the steam drum, the saturated steam is led into the superheater panels. The steam is superheated in different stages in order to control the receiver panel temperature and to secure the right superheated temperature for the steam turbine. A fired booster heater can be supplied for transient conditions.


The receiver systems can be supplied with valves, instruments, control system, interconnecting piping, de-superheaters, steel structure, insulation, design of cavity, etc.


Capacities vary from a few t/h to hundreds of t/h in a wide range from 10 to 150 bar.


All receiver systems are unique custom-made solutions to each customer.


Solar tower module system - a green energy source for industries

Working with solar tower receiver systems for utility plants has led Aalborg CSP to develop a solar tower module system, a renewable energy source for industries world-wide. The solar tower module system can supply power in the range of 250kWe - 10MWe. Read more about the solar tower module system.


Please contact us to get further information on Aalborg CSP solar tower receiver systems.