Solar Thermal Power Plants - Renewable Energy: Technology, Economics and Environment - page 219

Table 5.13 Technical data of the prototype in Manzanares/Spain

Tower height 194.6 m

Tower radius 5.08 m

Mean collector radius 122.0 m

Mean roof height 1.85 m

Number of turbine blades 4

Turbine blade profile FX W-151-A

Tip-speed ratio 10

Operation mode grid-connected or off-grid

Typical temperature rise in the collector 20 K

Installed name-plate capacity 50 kW

40,000 m 2 Plastic membrane - collector surface

6,000 m 2 Glass roof - collector surface

A variety of types of plastic sheet, as well as glass, were selected in order to es-
tablish which was the best - and in the long term, most cost effective - material. It
was found that glass is able to withstand even severe storms over many years
without damage and proved to be self-cleaning; occasional rain showers were
sufficient.
Completion of the construction phase in 1982 was followed by an experimental
phase, the purpose of which was to demonstrate the operating principle of a solar
updraft tower power plant. The goals of this phase of the project are (1) to obtain
data on the efficiency of the technology developed, (2) to demonstrate fully auto-
matic, power-plant-like operation with a high degree of reliability, and (3) to re-
cord and analyse operational behaviour and physical relationships on the basis of
long-term measurements.

60 60

1,200 1,200

50 50

1,000 1,000

Measured
global
radiation

Measured
global
radiation

40 40

800 800

Measured
electric
capacity

Measured
electric
capacity

30 30

600 600

20 20

400 400

10 10

200 200

Measured updraft speed Measured updraft speed

0 0

0 0

0:00 0:00 3:00 3:00 6:00 6:00 9:00 9:00 12:00 12:00 15:00 15:00 18:00 18:00 21:00 21:00 0:00 0:00

Fig. 5.30 Global radiation, updraft wind speed and power output of the Manzanares proto-
type (example: measured data at 8 th June 1987)

Time during the day in h Time during the day in h

Fig. 5.30 shows selected operational data from Manzanares for a typical day.
The data clearly show that for this plant without additional thermal storage the