[Greenbuilding] Solar Power Tower in Spain

[David Delaney]

At 02:06 AM 04/05/2007, Chris Green wrote:
>Link to a BBC News article about Europe's first commercially operating 
>solar power tower, in Spain, which, although unfinished, currently 
>generates about 11 Megawatts of electricity:
>
>http://news.bbc.co.uk/2/hi/science/nature/6616651.stm

The nameplate (i.e. maximum under perfect conditions) 11 
megawatt of this thing provides enough electrical energy 
for the electrical needs of 6000 homes?  Unlikely. The 
capacity factor will be at most 1/3.   (The capacity factor 
is the ratio of the equivalent constant power to the 
nameplate power. The equivalent constant power is the 
constant power that would deliver energy equal to that 
produced by the varying power of the facility over a period 
of a year.)

1/3 x 11e6 / 6000 = 611 watt per home, or 5352 kWh/yr, or 
about 15 kWh/day. Without implying anything about how much 
electrical energy you think _you_ might get away with, the 
actual average, which is what this article should be using, 
is about twice that.

And the capacity factor is probably less than 1/3.

At a guess, this plant might provide the electrical _energy_ used by 
2000-3000 homes. It cannot provide the whole 
electrical _power_ for _any_ number of homes, without 
currently non-existent facilities for storing several days 
of its average _energy_ output. Absent suitable storage for 
energy its full power output will have to be backed up by 
hydro or fossil fuel plants.

David Delaney, Ottawa