Solar power towers is a promising renewable energy technology, which can both generate and store energy, delivering dispatchable power.

1. Solar power towers: towards
a modular design
Mathieu Farges
Supervisors: C. Sansom,
P. Turner
Cranfield University College Road, Cranfield, Bedfordshire, MK43 0AL
mathieu.farges@gmail.com , c.l.sansom@cranfield.ac.uk , peter.turner@cranfield.ac.uk
Based on a MSc thesis done in Cranfield University
Solar power tower is a promising renewable energy technology, which can both generate and store energy, delivering
dispatchable power.
Objective: scale up the technology in developing an overall system design for a 300 MWth solar tower power-plant based on
multiple, modular, molten salt solar towers each with a nominal capacity of 10-25 MWth.
Twelve fields, with
a nominal capacity
of 25 MWth each,
are linked to a
single 300 MWth
power block and 6
pairs of storage
tanks
• Modular power tower systems are being developed ;
• Several modular fields are linked to a single power block
and several pairs of storage tanks ;
• Modular design allows the plant to start operating before
the full investment cost is reached, leading to better
financial reliability ;
• Other advantages include a greater availability, thus
greater reliability of supply.
1 km100 m
I. Solar power tower technology
II. Scale-up: large plant with single tower may not be a good
strategy
Example: solar field efficiency (from HFLCAL)
III. A modular approach is proposed as a relevant
new paradigm
Conclusion
Molten nitrate
salt is used as a
heat transfer
fluid and storage
media
Large plant advantages Large plant disavantages
Performance
- Lower relative parasitics
- Better conversion efficiency
- High optical losses
- Lower receiver efficiency
Cost
- Economies of scale (collector
system cost, relative
structures and improvement
cost)
- High tower cost
- Longer construction time
Economic
- Higher Risk
- Higher investment required
Solar field annual efficiency = 72% Solar field annual efficiency = 51%
380 m
4 000 m
17 MWth
565 MWth
IV. Expected Net Present Value profile
[1] Reilly, H. E. and Kolb, G. J. (2001) SAND 2001-3674: An Evaluation of Molten-Salt Power Towers Including Results of the Solar Two
Project. Livermore: Sandia National Laboratories.
[2] Norris, H. F. (1986) SAND 86-8001: Utilizing spreadsheets for Analyzing Solar Thermal Central Receiver Power Plant Designs.
Livermore: Sandia National Laboratories.
-5.0E+08
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-1.0E+08
0.0E+00
1.0E+08
2.0E+08
3.0E+08
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NPV($)
Time (month)
single tower Modular concept
Lower financial risk
Better financial
return