h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: The Electric Mountain, Dinorwig - A754698
Author: Jaziniho ( Tom Green ) - U194904

Dinorwig - Europe's Largest man made Cave and a unique feature of the Snowdonian landscape. Or none-feature as the case may be.

Nice article.
I thought the site was a disused slate quarry and that they just expanded the main cavern. The article seems to imply that they dug the cavern from scratch.
The water flows from Marchlyn Mawr into Llyn Peris a drop of over 500m.

You'll probably need to add UK to the end of the title so people know where in the world it is.

As far as i gather the old slate mines actually had to be filled in, rather than a case of expanding the already existing caverns. And yes, adding UK might be good idea, think i'd get away with just adding Wales? And i'll just add something about the lakes now, thanks for the info. If the truth be told I was actually writing the article off the facts and figures that stuck in my memory when I visited the plant a couple of months ago, so there isn't nearly as much detail as there could be i suppose!
thanks
---
tom

" tomorrow never knows "

You might get away with Wales but style guidelines for the guide mean that it will get added (all place related entries have to have the country in the title).
It was some time back when I went round there. I seem to remember that they said one of the turbines was kept spinning with compressed air so that they could get the high turn on speed.

It's a good entry, Tom, but I think you're right, it could do with a bit more detail. And factually it's only sort-of-ok.

For example, the adverts. It's not just a question of adverts. There's also a surge at the end of a big match on the BBC, for example. And the annual biggie is the nation's Christmas dinner and the Queen's Speech.

Although there's been an increase in the sale of electric kettles, it should also be pointed out that there's been a huge decrease in demand from the electricity-intensive industries such as coal mining, ship-building, steel mills and so on. It was really the industrial electricity demands that led to the building of this facility.

Mention that there's an alternative spelling, Dinorwic, by which it's usually known in England.

It is of course a net consumer of power rather than a net generator. So its main function is effectively as a storage facility, since an important difference between electricity and other fuels is that elec cannot be stored in any great quantity or for any length of time.

The description of the National Grid as 'criss-crossing' suggests something a bit chaotic, I thought, whereas in fact it is a very ordered and carefully-designed and controlled distribution system.

It's a bit misleading to suggest that other power stations can take hours or days to come online. You can keep a traditional power station on standby and bring it online in less than an hour. Even when it is not on standby it shouldn't take more than half a day to bring it in. Given that TV commercial breaks are scheduled and known in advance, they shouldn't take the authorities so completely by surprise that they have to suddenly bring in Dinorwic within seconds. In any case, it must take more than seconds to get the water in at Dinorwic to start the turbines turning.

Also, it is not the case that there is an 'excess of power' (whatever that means) at night. It's all about managing supply and demand. Electricity can be produced more cheaply at night than during the day, for various reasons, as indeed it is cheaper in summer than in winter, and cheaper at the weekend than during the week.

Also I think you'll find that the tour costs £5 for an adult, with some concessions and family tickets etc. It's not really the best idea to quote such amounts, as they will obviously vary in time.

I think Dinorwic may be the only hydro-electric plant in England/Wales, though of course there are several in Scotland. You might like to check this out.

Anyway, you have the basis of a good entry, and these are just a few points to mull over. If you haven't yet done so, I suggest you have a look at a few electricity-related web sites so you can sharpen things up a bit.

Good luck!

Bels

Yes, will get some of the ammending done in a sec, but just a few points. Firstly i didn't think that Dinorwic was built because of the demands of industry, industry tends to have very regular patterns of demand, high in the day time, lower in the evening and at weekends. Industry tends not to create very large surges, well they may do in one specific area, but on a national scale. I mean all the steel mills didn't just turn on at exactly the same time.

Yep, hadn't thought about the Welsh spelling actually, i'm not really sure of the rules on article titles, is it ok to put Dinorwig and Dinorwic in the title? Or will it not matter because if both are in the text as no matter which way it is spelt in title it will still be found by search engine either way it is spelt by user? That was a really poorly constructed sentence, sorry!

Yes, i suppose its purpose is really that of a storage facility, would drawing an analogy between Dinorwig and a rechargable (sp?) battery be misleading?


I can't remember the exact context of the bit about National Grid but would something along the lines of " The company in control of the network of power cables that allow the efficient distribution of electricity throughout England and Wales " ( I think Scotland's is run separately isn't it? )

It takes 12 seconds for Dinorwig to reach its maximum output. And yes, they can predict when the power surge is about to come and what usualyl happens is that the turbines are started with pressurised gas, so that when the water comes it can start producing the power almost immediately.

In a way there is an excess of power, it is far cheaper to keep a powerstation running proudcing a limited amount of power than it is for them to disable it and just turn it off, then restart it again in the morning. Really though i think it comes down to that bit in the article being particularly badly worded, I wasn't trying to suggest there was an excess of electricity really. And the electricity isn't cheaper to produce at night and weekends, infact i suspect it costs more to produce as the labour force would most likely be on higher wages than the normal week day workers. The electricity is sold on cheaper though, the electricity companies reduce prices to try and stimulate demand at normally quiet times.

Ah yes, of course. I'm not and adult, that's why i had the figure as £2! Sorry, I forget about that sort of thing. And yes, it almost certainly would be best to leave out a price, better with a simple "tours are relatively inexpensive"?

It certainly isn't the only HEP station in England and Wales, there is another station extremely similar to Dinorwig a few miles from it in Ffestiniog? (sp can be checked). I think there are also a few other HEP stations dotted on dams across Wales, I suspect the dam on Llyn Clyweddog is used for HEP, but it may just be to create a reservoir.

anyways, thanks for your input, I won't make the changes quite yet, a bit of feedback on some of the stuff above is almost certainly needed if it's to be got right

thanks
---
tom

" to die by your side "

The technical term for Dinorwig and Ffestiniog is a pumped storage HEP.
The company that runs the two is First Hydro who have a website at http://www.firsthydro.co.uk (which also has links to the snowdon weatherstation info and webcams that they sponsor).

Oooh, thanks, i'll have to check that out, but in the morning i think! On exam leave at the moment and really should get some sleep so i can get some revision done in the morning.
thanks
---
tom

" think of me when you're coming down "

Take a look at the National Grid website.

You don't need both spellings in the title. If it's in the entry somewhere the search engine will find it.

You haven't got quite the right idea about industrial load profiles or the economics of night-time electricity generation. For the purposes of this entry that doesn't matter, but there's no way it's going to be cheaper to keep non-nuclear plant running if you can turn it off or put it on standby and go home, saving fuel and wages. The clever thing is the way they decide what to turn off and what to keep running.

Anyway, sleep well!

Bels

Good article! Reminds me of my last visit, and its amazing how big the caverns are!
Rgds,
Kenrick

Hope that exam week wasn't too bad!

Hey, it would be nice to see the suggestions being acted upon (either put them in or state that you won't -- which ever you decide since it's *your* entry).


And I was sooo close to pulling the Scout's trigger

I don't think that this article should really contain an in-depth study of why hydro-electric power plants are so important - that would be a good topic for another article though!

Having just one example (advert breaks in films) is fine, I reckon.

Do you have any idea how much the dam cost to build?

yeaaaaaaaaaaaaah, going to get round to updating and finishing it now! sorry it took so long, been away on exams, wasn't exam week, more sort of exams 2months, will get round to sorting it out now though, got plenty of time off now.
sorry!
---
tom

"you are the one that makes the difference"

Hey, cool entry!

I think you could compare Dinorwig HEP to a capacitor.

You might want to add this link:

http://www.fhc.co.uk/DIN.htm

Very good,

HELL

I thought so.

looking at the link you just gave, It is obvious that the intended use for this site is not to cope with millions of people turning the electric kettles on when eastenders finishes (although it can be used for that as well).

The actual intended use is to take all of that inconveniently produced nighttime electricity, which has to be produced to keep the generators from breaking down, and to store it for the daytime when there is an under-capacity in the system.

Of course, with the dynamic response that this system is capable of, it is idealy suited to fast bursts of electricity while the other systems come up to capacity.

It is also obviously supplying most of the electricity during the peak demand, to maximise the difference between the 2.5p / unit that you can buy econemy 7 electricity for and the 7.5p / unit that it sells for at peak (although it is hard to get them to pay you that much).

In fact, it is extrordinarily difficult to design asystem that can work in that small price difference.

It is thus better thought off not as a capacitor, but as a battery.

Yep, battery... that's right.

HELL

This entry has been scouted - can I process it for inclusion in the Edited Guide or does it need a little more work?

Let me know either way.

Ashley

I haven't been notified either way, so I'm freeing this entry to be picked again when it is updated.

I'm *really* looking forward to getting this into the Edited Guide.

Hello? Hello?

Capacitors are typically very small, batteries big.

I believe that a hydroelectric reservoir is better and cheaper for the purpose than batteries, so battery is right for that part of it.

But the turbines at Dinorwig, when they're spinning, are loaded with kinetic energy like an inductor.

A distribution system for AC electricity has to stay synchronous to a fraction of a second. The need for "spinning reserve" is so that a sharp increase in demand doesn't slow the generators down to the point where they fall out of sync and send +220V when everybody else is at -220V (I'm exaggerating).
I've been in the control room at Dinorwig (my brother was Chief Biologist) and saw that the turbines on spinning reserve, running in compressed air, were consuming 4 MW just to be ready for a demand surge. Any other way of responding so quickly, such as gas turbines, would have cost significantly more.

At the time that the project was built, the CEGB estimated that the peak load response savings in cost was quite large, and they seemed to be saying that it was equal in importance to the other property, which is that even at 75% efficiency (what you get back in the daytime from the energy you paid for to pump the water up there) this was an economical way of meeting daytime loads. Small low inertia generators are expensive per kilowatt to run. Even with North Sea gas.