power stations / electric

lookitsjonno

lookitsjonno

lookitsjonno

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Joined
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Midlands
A question that has for a long time amazed me... how on earth do power stations generate enough electrictity to cater the whole country? I mean, imagine at this time in the UK how many PC's, TV's, Cookers, Underground Trains, Trams, Kettles, Irons, Hoovers etc there are on in homes/workplaces at this present time? Millions. How can they all be powered by steam generators :eek:

Random post, but after reading the gas/electric kettle boing thread it got me wondering!

Perhaps some physics expert can explain?
 
The peak demand on the coldest day in winter is about 60GW IIRC. Drax's output is about 4GW, so just 15 Drax sized power stations would be needed.
You should go on a tour of a big power station - they are absolutely massive.

The thing that amazes me is that they can constantly balance supply and demand to keep the grid frequency at 50Hz.
 
i worked in a power plant during one summer doing vibration tests on the power generation turbines. These were about 4-5stories high and would generate about 400MW of power each. Puts my current aeroderivative ones to shame.
 
They might be a bit more restricted post 9/11 but I've done tours of Hunterston B (nuclear) and Cruachan (hydro) in the past. The Hunterston one was a pre-arranged school trip but the Cruachan one was a turn up and go effort. Quite impressive too, the turbine hall is the size of a football pitch carved out of solid rock half a mile inside a mountain.
 
I don't think you'll get into a nuclear station any more. I had a tour of Longannet, but that's only cause I work for the company! As far as I know they do offer tours.
Cruachan is quite good, esp if they take you up to the dam. Entry is free if you don't travel by car (or do travel by car but park round the corner and walk the rest of the way!)
 
Along side all the big Nuclear/Gas/Coal plants there are also Hydoelectric power stations which dump massive amounts of energy into the National Grid at peak times - like when the kettle goes on at half-time!

One such Hyrdo power station is Dinorwig which is also buried inside a mountain [Elidir Fawr in Snowdonia]. You can also go on tours there.

There is also a Hydro power station in Blaenau Ffestiniog which you can also tour.

On Anglesy there is a small MAGNOX Nuclear power station called Wylfa that does tours.
 
big_white_dog84 said:
The thing that amazes me is that they can constantly balance supply and demand to keep the grid frequency at 50Hz.
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That's surprisingly easy. The coal stations supply the base load because they can't change output easily. The nuclear and hydro stations can vary their output easily to meet peak demand so they really only operate flat out at busy times. A wee bloke at the National Grid basically phones up and asks someone to open the taps a bit more and voila!

Interestingly Cruachan uses the excess electricity generated overnight by coal stations to pump water back into it's own reservoir so it's not reliant on rainfall.
 
Frequency isn't affected by demand however voltage is - hence why your lights dim occassionally when you power on something big. My old bathroom light used to be really bad for it when you turned on the shower.
 
I've toured both Hunterston B (twice) and Cruachan. Hunterston was quite a tour if I remember correctly but I'm fairly sure they don't do tours anymore which is a shame. One thing I remember is that Hunterston B (the 'A' reactor in currently in the latter stages of decommissioning) can produce enough electricity to power 50% of Scotland alone.

rpstewart said:
Interestingly Cruachan uses the excess electricity generated overnight by coal stations to pump water back into it's own reservoir so it's not reliant on rainfall.
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Further to this, it actually takes more energy to pump the water up to the reservoir than the station can produce!
 
Dunky said:
Further to this, it actually takes more energy to pump the water up to the reservoir than the station can produce!
Click to expand...

Of course it does, otherwise you'd have to be using perfectly efficient generators/motors and/or have discovered perpetual motion... ;) :p
 
So Cruachan is essentially a huge load-balancer, acting in a sense as the output variation that coal stations don't have?

If so, is that true of all hydroelectric power stations in the UK? If my understanding is right, you'd need a huge natural movement of water to have a hydroelectric power station that produces a useful amount of power without using more to pump the water back up.
 
The National Grid is a fantastic thing, the problem is that once you generate electricity you have to use it as you can't store it.

My favourite power station is :-

Dinorwig Power Station

http://en.wikipedia.org/wiki/Dinorwig_power_station

as it not nuclear, I'd love to look around that :)

Mr Mag00 said:
its the waste as it pushed around the country that annoys me, more micro generation please
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Indeed, I've often wondered how much energy is wasted by long distance transmission, better to transmit it and say lose 50%.

HEADRAT

P.S. Remember looking around Dungerness (nuclear) Power station at school.
 
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You could redo everything for HVDC transmission and cut the losses, but it wouldn't be worth it.

Now...HVDC from solar power stations in Africa, that's a different story. That would be worth it. It's also feasible - Canada has had a similarly long transmission for years.
 
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