[clug] OT: Solar power recommendations and advice

[steve jenkin]

Felix Karpfen wrote on 21/04/10 7:21 AM:

> As pointed out in the previous (not quoted) posting, power stations will 
> fire up enough generators to supply the anticipated demand (based, 
> presumably on previous usage patterns) and it takes some hours for the 
> generators to come up to speed and produce electricity at the most 
> economic cost.

I understand it takes around a week to start a 660MW 'unit' from cold.
Can't just turn them off, either.
Couldn't quickly find a reference.

There's a different problem of increasing output - raising boiler
temp/pressure by increasing coal-feed rate. That could be achieved in hours.

Steam Generating units can be taken off-line, but have to be kept idling.

An aside in a piece on Gas Turbines (stationary jet engines) fired with
Natural Gas hints at some of the problems.
These are the Great White Hope for peak demand in 'traditional' power gen.
<http://files.asme.org/ASMEORG/Communities/History/Landmarks/5501.pdf>

"An outstanding feature of the gas turbine is its short start-up time.
Where a steam turbine would require several hours to reach its operating
temperature in order to prevent warping of the heavy parts forming the
casing and rotor, the gas turbine can produce full power within about 15
minutes."


> If the producers get it wrong, you either get brown-outs (when there is 
> not enough to meet the demand) or waste (when some of the available 
> electricity does not find a buyer).

Exactly this was covered in detail in the first of the 3-part BBC
series, "Britain from Above". The UK has a unique synchronised event
every work day: at the end of popular TV shows, people 'put the kettle
on'. It's quite a balancing act for the controllers.
<http://www.bbc.co.uk/britainfromabove/>

On the relative costs of power sources, from 2006:
<http://en.wikipedia.org/wiki/Relative_cost_of_electricity_generated_by_different_sources#Analysis_from_different_sources>


<snip>

> Felix Karpfen


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Steve Jenkin, Info Tech, Systems and Design Specialist.
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