Solar power tower is a promising renewable energy technology, which can both generate and store energy, delivering dispatchable power. Poster from a MSc thesis work.

1. Modular power tower
system design
Mathieu Farges
Supervisors: C. Sansom,
P. Turner
Cranfield University College Road, Cranfield, Bedfordshire, MK43 0AL
c.l.sansom@cranfield.ac.uk , peter.turner@cranfield.ac.uk
www.cranfield.ac.uk/energy
Solar power tower is a promising renewable energy technology, which can both generate and store energy, delivering
dispatchable power.
Objective: develop an overall system design for a 300MWth solar tower power-plant based on multiple, modular, molten salt
solar towers each with a nominal capacity of 10-25MWth.
Temperature
(°C)
Density
(kg/m3)
Heat capacity
(J/kg.K)
Absolute
viscosity (Pa.s)
Thermal
conductivity
(W/m.K)
300 1899 1494 0.003 0.500
600 1708 1546 0.001 0.557
Molten nitrate salt has high density, low absolute viscosity, acceptable thermal
properties and low vapour pressure
Temperature
(°C)
Heat loss
(W/m)
Temperature
drop (°C/km)
Pumping
power (W/m)
Pressure drop
(bar/km)
300 105 3.2 4.38 3.8
600 177 5.3 4.29 3.3
Thermal and pressure losses in a cold and hot pipe network for a 10 MWth receiver
(22 kg/s), for the most economical insulation
Pipe insulation and
diameter design
choice is a trade-off
between pipe cost,
insulation cost, heat
loss and pumping
loss
0,00%
0,20%
0,40%
0,60%
0,80%
0 10 20 30 40 50 60
Fractionalpumpingloss(%)
Receiver nominal thermal power (MWth)
This fractional
loss however
increases when
receiver nominal
thermal power
increases
Process and Instrumentation Diagram for power tower system
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
• A modular power tower system design has been
developed
• Safety requirement and FMEA has been produced
• Optimisation criteria and constraints has been
specified
• Extended pipe network does not provide significant
disadvantages
• Modular design allows the plant to start operating before
the full investment cost is reached, leading to better
financial reliability
1 km100 m
I. Molten nitrate salt is used as a heat transfer fluid (HTF) and
storage media
II. Thermal and pressure losses has been assessed
III. Pumping power required is low compared to receiver
nominal thermal power (less than 1%)
IV. The receiver’s tower concept has been designed to be
as simple as possible, while considering risk and
maintenance issues
V. A modular layout has been proposed
Conclusion