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Gas powered, oil fired and coal fired power stations, a lot imported from France by undersea cables
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It's a two way thing with France, and with Scotland. We don't just take.
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It's a two way thing with France, and with Scotland. We don't just take.
So which way's net?
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So which way's net?
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Massive amount flows south out of Scotland into England and across to Northern Ireland. And as much of the new renewable energy power stations are being built in Scotland, this is going to go up even more (assuming planning permission is given for the new lines to carry it across the border!).
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"So which way's net?"
Well it seems from the links provided by Mark that it depends on price.
In 2004 we seem to have imported more than we sold, and the previous three years it was the other way round.
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Got me interested. Maybe we don't impoirt much from France.
"There are numerous power stations in the UK. There are around 23 large coal fired plant (some of which also burn some gas or oil), 17 nuclear plants, 8 large oil plants and 11 new combined cycle gas turbines (CCGTs) and several others. Large in this context means over 100MW. (The percentage of generation by fuel type in 1995 was 48% coal, 23% nuclear, 17% CCGT and open cycle gas turbines, 9% interconnectors and 1% oil and the remainder hydro and the new renewables)."
Also see here www.parliament.uk/post/pn163.pdf
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Go here for information about sharing electricity...
www.nationalgrid.com/uk/
and select "Interconnectors" from the drop down list.
Go here for some facts and figures about generation...
www.electricity.org.uk/default.asp?action=article&...2
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If you really want an interesting day out and see electricty generation in action , go to Llanberis in Snowdonia and visit Dinorwic Power Station which is actually built inside a mountain.
Magic Mountain tours are run by the electricity company and are fascinating.
The power is generated by releasing water stored at the top of the mountain through the turbines and into a reservoir at the bottom where it is pumped back up to the top . It is a very efficient way of balancing demand because the power is brought onto the grid vitually immediately at times of high demand whereas it takes a lot longer to start up your average coal, gas or nuclear station.
The turbine hall inside the mountain is larger than St Pauls Cathedral and well worth a visit.
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Would I be right in thinking that is more of an 'energy balancing' system, rather than generating?
I assume it uses power from the grid, when there is excess, to pump the water up to the top, then when extra is needed for the grid, that is released to provide extra power?
I assume that it's also less than 100% efficient, and therefore overall it uses more energy than it provides?
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www.fhc.co.uk/DIN.htm
Actually up in the area this weekend, fine motoring roads no too heavily Policed (contrary to the popular view)off the dreaded Arrive Alive "routes"
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That's right. However I understand the water is pumped back up at nightime when electricity is cheaper. Something to do wth the fact that it is cheaper to leave power stations running at low capacity than to switch them off and on again.
In essence, it is a giant rechargeable battery.
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Of course they generate electricity, thats what they are in business for and IIRC they have five pretty large turbines in the turbine hall.
How do you think they make any money but by selling to the consumer via National Power and the grid?
The advantage Dinorwic have is that they can respond immediately to demand and therefore can sell to National Power at a higher rate than other generators.
This is particularly handy when sudden peaks of demand drain the grid and supplies drop dramatically -- ie half time when footy is on the telly and everyone switches on their kettles.
Its really a very interesting place for anyone who wants to learn about electricity generation and they also have a big exhibition hall and proactive displays ideal for kids.
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"Of course they generate electricity"
Nope - it STORES electricity generated elsewhere. To be pedantic it converts it into another form of energy and then converts it back when required. It buys electricity cheaply, converts it, looses some in the conversion, and then sells it back at a higher price.
Thats not to take anything away from what is a magnificent and practical piece of engineering.
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Having just clicked on the link above they actually have 6 turbines which generate the power by day and reverse to become pumps by night to pump the water back up to the top of the mountain.
They excavated 1 million cubic metres of earth to build it - An amazing feat of engineering all round.
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"In essence, it is a giant rechargeable battery."
Indeed - but what a battery
0 - 1,320 Megawatts in 12 seconds.
5 hours at full "discharge"
7 hours recharge time tho!
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Sorry RF - You are wrong.
The Dinorwic power station generates power as and when requested to by the National grid.In times of high demand they are phoned up and asked to start generating power to the grid - it does not store electricity.
If you don't believe me do what I did and visit the place or ring them up and ask.
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have you checked out the weblink above ? It explains it all.
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I actually phoned them up and asked not 10 minutes ago!
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>>National grid
National Grid [Transco] is a company who, amongst other things, supplies the electricity transmission network to the UK and as such both words are capitalised.
That transmission network is occasionally referred to as the national grid, where "national" is an adjective and not capitalised.
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Even more pedantic than usual today Mark!
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I'll leave you two to argue about Dinorwic but the other one in Ffestiniog certainly does store electricity behind it's big dam, in the way RF describes.
I've been on a tour of there myself and I have to say it's a pretty big station. Of course it's all computer controlled up there but before they had teams of people working there to check pressures and adjust valves: the oil pumps for the bearings alone are huge and pretty noisy at that. Driving up to the dam is pretty scary with the shear drop on one side.
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Mike Farrow
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Helicopter is correct, it does not store electrical power, it stores potential energy (ie large mass of water at a great height) which it can convert to electrical energy on demand.
A battery cell also does not store electricity, but contains chemical energy which can be converted to electrical energy.
A capacitor is capable of storing electrical energy (or charge).
During off peak, electrical power from the grid is used to pump water up to the resevoir thus converting surplus power to potential energy, on demand the potential energy s then converted back to electrical power, both conversions are less than 100% efficient but storing it this way is very convenient.
A similar effect would be to spin up a very large flywheel with off peak electricity thus storing electrocal power as kinetic energy. This kinetic energy could then be used to turn a generator on demand thus converting the kinetic energy back to electrical power at a more convenient time.
Stargazer
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"Sorry RF - You are wrong."
Sorry helo me old mate, you are only selectively looking at 41% of its operating cycle.
Its has a 12 hour charge/discharge operating cycle. 7 hours recharge, 5 hours discharge. It is using electricity to generate electricity through storage and is therefore not a Generator.
So there
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it uses low peak electricity from the grid to pump the water back up the hill.
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From their website.
Dinorwig's reversible pump/turbines are capable of reaching maximum generation in less than 16 seconds. Using off-peak electricity the six units are reversed as pumps to transport water from the lower reservoir, back to Marchlyn Mawr.
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It is a net generator although it does consume some of its own [excess] production ?
I think we're getting into semantics. I also think we're getting into an area for which this thread was not intended; so unless you have a specific question, I think we'll leave it there.
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It can only be a net generator if its 7 hour recharge time consumes less watts than its 5 hours discharge time produces.
The last time I checked it was harder to push water up a hill than let it run down so unless the welsh pixies have discovered the holly grail and can defy physics then my argument stands.
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The last time I checked it was harder to push water up a hill than let it run down so unless the welsh pixies have discovered the holly grail and can defy physics then my argument stands.
Well put RF, plus power is lost in the turbine/pump volute, bearings, and power transmission. Unless it monsoons up there 24/7 and someone has designed the lossless pump and turbine it can never be a net generator.
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Mike Farrow
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Is anyone else getting bored with this argument??
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If you accept that RF is speaking hypothetically, which I believe he is, then his analogy of 'rechargeable/storage' is quite correct.
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Ok The figures.
It requires 11,550 Megawatts to pump the water up the hill for a full charge cycle.
Generates 6,600 Megawatts on a full discharge cycle
Net loss
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'It is using electricity to generate electricity through storage and is therefore not a Generator.'
RF - It is using water power to generate electicity at the demand of National Grid (OK for you Mark?.).
I agree that they use electricity to pump the water back up to the top of the mountain.
However, because of your insistence I took the trouble to actually ring them up and clarify directly with them.
I was told that the power is generated and supplied direct to the national grid ( all right Mark?)when National Grid ( OK Mark?) ring them up and ask for it.
It is not stored.
I am going to leave it now as I have a business to run!
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Of course its stored! where did it come from! They bought it and stored it!
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RF, read my post, they buy electricity and convert it to potential energy which is much easier to store, on demand they then convert this back to electricity.
They do not store electrical power!
StarGazer
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RF - I will refer you to Stargazers explanation above as I really do have to fly ( literally).
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Where did I say its stores electricity? All my posts states it converts it.
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Everyone seems to assume it doesn't snow or rain on Dinorwic!
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"Everyone seems to assume it doesn't snow or rain on Dinorwic"
If the rain and snow is 7,000,000cu metres every 5 hours then I conceed its a net generator of electricity
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Come on helicopter, this is simple physics!
Cheap electricity is bought from the grid to pump the water uphill. At peak times, the water is then let back downhill, and produces expensive electricy (ie at peak rates)
It works on an economic level because of the difference in price between nighttime and daytime electricity.
It cannot produce a net gain. To do so would be to break the cardinal rule that you can't get energy for nothing.
All engines are effectively devices for turning one sort of energy into another (ie chemical potential energy in petrol to kinetic energy) What this system does is to use electrical energy to created gravitational potential energy (when the water is pumped uphill) and then to reconvert that potential energy into electrical energy when the water is released back downhill again. As both conversiions will not be 100% efficient, it must be a net consumer of electricity.
This is a cracking friday afternoon thread!
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Where did I say its stores electricity? All my posts states it converts it.
In your post above
Of course its stored! where did it come from! They bought it and stored it!
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Ok in that one post I missed out "coverted it" you have me there. Does not alter the fact it only provides the National Grid (Transco - Ok with you Mark?) some 56% of the electricity it consumes from the National Grid (Transco - ok with you Mark?)
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Where did I say its stores electricity? All my posts states it converts it.
Mine does in error.
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>>I was told that the power is generated and supplied direct to the national grid ( all right Mark?)
Well, not entirely. Given the three interconnectors I am not sure that "national" grid is quite as appropriate a term as it once was. It might, perhaps, be better described as the international grid. Having said that, it might be acceptable to continue to refer to the act concerned as "supplying it to the national grid" since it is then shared with a number of other national grids rather than with an international grid. Although even that would bring into question the use of the word "the" as in "the national grid" since it would be more accurately described as "*a* national grid"; one of many.
Further perhaps they are not supplying it to the/a national grid at all but is supplied to National Grid who then feed it into the/a national grid.
These things are very problematic for a friday afternoon.
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These things are very problematic for a friday afternoon.
Agreed, must go and get a cup of tea (chemical energy) then walk to the station and catch a train (convert to kinetic energy) and arrive 12 minutes later up in the Cotswolds (potential energy).
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Helicopter said "I am going to leave it now as I have a business to run!"
This has made me curious, as many of our most prolific posters seem to run business and/or work for themselves. How on earth can our captains of industry have the spare time to be playing around here, when many "ordinary" people are barred from visiting sites like this during the working day due to "company policy"?
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Because smokie, they're the boss. Or a student avoiding work.
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Mike Farrow
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"Or a student avoiding work."
At least you didn't mention Adam by name.
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have you noticed he is never around when things get hard and technical?
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wow! 50 posts to my question. much more knowledge on subject now. intersting links too/
Thanks for replies!
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Brilliant!
A 50 post discussion, where everyone has basically agreed with what I said originally, but argued about semantic points. :D
Helicopter: I certainly wouldn't argue that it is an incredible achievement, but the reason why I suggested it wasn't overall a generator of energy is that, without energy already supplied to the grid by other, more conventional generators, it could not actually supply energy itself.
It takes energy from the grid, stores it as potential energy (water at top of hill), then at need converts this to kinetic energy (water running down hill) then to electrical energy (via the turbines)
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