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[Markjay]

I've got a dynamo rigged up to the excersise bike, put Mrs AA to work on it, every time the lights go dim, I give her a good slapping, whoops, got to go, can here her coming

 

..you are not hamsters, are you?

[Auto Addict]

I've got a dynamo rigged up to the excersise bike, put Mrs AA to work on it, every time the lights go dim, I give her a good slapping, whoops, got to go, can here her coming

 

..you are not hamsters, are you?

Now there's a thought, could buy her a wheel......

[x25xe]

[I thought the power companies sold the 'not needed' leccy to Europe/etc  when over producing.....or am I wrong there?

Actually, in the UK when demand reduces, generation is taken off-line.  There is never over generation.  In winter, especially last winter, the UK had, at times, all of its oil fired generation on load, there was nothing left!!!, nobody realises just how desperate it got.  Taking into account the cost of oil at that point, it shows just how close the UK came to brown outs.  There was a program recently which told of the unstableness of gas supply.  A spokeswoman for a glass manufacturer was unable to buy gas.  The price was rising so quickly, no one was willing to sell her it as it would have been worth so much more at the end of the transaction.

Mike,

All this info about power stations and the National Grid is great.  I am, and always have been, totally fascinated by the grid, how it works, how the frequency is kept at a constant 50Hz and how it keeps on going seemingly regardless of total load.  I think that it is amazing and very few people have an appreciation of it (or probably even care).  I always remember that huge switching plant (I think it is a switching plant) near the M6 where you can see the million volt power lines coming in and the oil filled switch gear ............ amazing stuff.

One of my wishes is to visit a power station some time and be able to see the generators humming away and view the control room.  Sad, I know but still.

What I would like to know is how does the grid actually work?  Why is it that Sub Stations are being removed?  Do any power stations have open days?  Why have some power stations been closed?  Is there any on line resource that could answer these questions?

I would love to know more about how the generation is controlled and how stations are brought on line and taken off again to suit fluctuations in demand.

[Ken T]

The figs of 15% and 20% efficient for engines are eye opening. We need to make better use of can energy usage. For example, a lot of the energy in an engine is given off in heat. Why not plumb a slow cooker into the cooling system?. That way, when you set off to go home from work, just turn on the heat tap and your tea is cooked when you get home!. OK a bit of a joke, but we used to do this to bags of chips many years ago Perhaps the way is to make better use of the energy we use. Toyota have spent mega bucks developing (sorry flinging together) new (Old) technology, and the political capital they can make from it is huge. Never mind if it doesn't work very well, they stand to win big time. Public thinking about 'new is good' needs to be changed before we see sense. For example I have 3 PC's that I run, one on Ebay, one on OOF, and one on Yahoo. They are so cheap that its either use them or throw them out for scrap. However the power used is quite high, (400W each?), so if I changed over to using laptops (about 60W each) I could cut my power use considerably. And in in dear old Bradford, they are 'regenerating' lots of houses, by spending about £3500 each on stone blasting the outside and building nice walls using the same kind of expensive stone bricks, front and back. Yet a large number of these houses are single glazed, have crap heating systems and I'll bet the lofts aren't insulated. In some ( Cold!) countries Houses use engines for generating electricity, but they also use the heat to heat their homes, thus achieving better efficiency. Perhaps we should fit heat storage units in our car boots?  

[Markjay]

One of the things that boffins were experimenting with on-and-off over the past 10 years or so is ceramic engines – the idea is that ceramics can stand much higher temperatures than alloys so engines could run hotter and there would be no need to cool it down (=waste heat energy). This sort of engine should in theory be more efficient and have less energy loss. Alas, like Rover’s Jet-Turbine propelled car of the fiftees, the idea hasn’t actually matured to mass production stage…

[Markjay]

http://news.bbc.co.uk/onthisday/hi/dates/stories/march/8/newsid_2516000/2516271.stm

[Markjay]

Hijacking my own thread    :

[TheBoy]

[I thought the power companies sold the 'not needed' leccy to Europe/etc  when over producing.....or am I wrong there?

Actually, in the UK when demand reduces, generation is taken off-line.  There is never over generation.  In winter, especially last winter, the UK had, at times, all of its oil fired generation on load, there was nothing left!!!, nobody realises just how desperate it got.  Taking into account the cost of oil at that point, it shows just how close the UK came to brown outs.  There was a program recently which told of the unstableness of gas supply.  A spokeswoman for a glass manufacturer was unable to buy gas.  The price was rising so quickly, no one was willing to sell her it as it would have been worth so much more at the end of the transaction.

Mike,

All this info about power stations and the National Grid is great.  I am, and always have been, totally fascinated by the grid, how it works, how the frequency is kept at a constant 50Hz and how it keeps on going seemingly regardless of total load.  I think that it is amazing and very few people have an appreciation of it (or probably even care).  I always remember that huge switching plant (I think it is a switching plant) near the M6 where you can see the million volt power lines coming in and the oil filled switch gear ............ amazing stuff.

One of my wishes is to visit a power station some time and be able to see the generators humming away and view the control room.  Sad, I know but still.

What I would like to know is how does the grid actually work?  Why is it that Sub Stations are being removed?  Do any power stations have open days?  Why have some power stations been closed?  Is there any on line resource that could answer these questions?

I would love to know more about how the generation is controlled and how stations are brought on line and taken off again to suit fluctuations in demand.

I developed a sad fascination about 15 years ago when we on hols in North Wales with friends.  Looking for something to do on the first day, we went to a hydro electric power station at Blaneau Festiniog (thats spelt wrong!). Absolutely fascinating. So the next day we went to the hydro electric at Snowdown (more disappointing, but the scale of it built entirely underground was amazing), and the next day to a nuclear one they were decommissioning...

[supermop]

I've always had a sad fascination for wanting to see a power station. It's just big things that make LOTS of power, gives me tingles down my spine

[miked]

Mike,

All this info about power stations and the National Grid is great.  I am, and always have been, totally fascinated by the grid, how it works, how the frequency is kept at a constant 50Hz and how it keeps on going seemingly regardless of total load.  I think that it is amazing and very few people have an appreciation of it (or probably even care).

I think its amazing as well, which is a good job as its all I do.  

Every alternator connected to the UK grid is spinning at a constant 3000rpm (3000/60seconds = 50 cycles/sec or Hz).  The large units (steam turbines in the case of nuclear, coal and oil) are directly coupled to the alternator, therefore are also spinning at 3000rpm.  The largest steam turbines in the UK are at Drax, 660 mega watts (MW).  The majority of the rest are all 500MW machines.

There is a diverse range of units providing frequency response.  These include the larger coal and oil units, hydro electric pump storage (very fast to come on line) or small gas turbines (most large power stations also have a number of small gas turbines used to support their sub-systems and to provide frequency response when the grid is in real trouble).

The easiest way to imagine how the grid stays at 50Hz (and without getting into electrical power and machine theory :-/), as more load is required (demand goes up, maybe everyone switching on their kettles in the ad break between big brother), all the machines connected to the grid will start to slow down (like a car going up a hill with no extra throttle).  Those machines selected to frequency response see this effect in the grids frequency and their control systems take on this extra load, to bring the frequency back to 50Hz.  Obviously one machine can not achieve this by its self which is why there are lots of units selected to frequency response.

This deals with the fine control of the grid frequency, more course control is achieved by a balancing mechanism where load is balanced to demand (see link at the bottom).

http://www.nationalgrid.com/NR/rdonlyres/2106CEB2-E2C0-4AC9-A8FE-940DEFCCCCEB/3273/frequency.pdf

An important thing to appreciate here is the 'momentum' of the grid.  Large and sudden changes in demand (a unit trip / blast furnace starting, large fault developing somewhere on the grid or whatever), it is the momentum of these large pieces of spinning metal that enables the grid to ride through the disturbance.  A large 500MW machine is about 150feet long and at the low pressure end, the turbine blades are about 10 feet in diameter (a big piece of metal spinning very quickly)

• Steam pressure at the turbine inlet (high pressure end), about 160Bar

• Steam temperature at the turbine inlet, 568degC

This is referred to as super heated steam, invisible to the human eye and would cut through you like a knife through warm butter  :-/  Steam venting to the atmosphere at that pressure would immediately burst both ear drums.  So pritty serious stuff.

I always remember that huge switching plant (I think it is a switching plant) near the M6 where you can see the million volt power lines coming in and the oil filled switch gear ............ amazing stuff.

The largest voltage on the UK grid is 415kV and is referred to as the super grid, you may be getting confused with MW but still a very large voltage.  Get within 3 meters of such a voltage line (whilst touching ground) and you will fry.  

One of my wishes is to visit a power station some time and be able to see the generators humming away and view the control room.  Sad, I know but still.

What I would like to know is how does the grid actually work?  Why is it that Sub Stations are being removed?  Do any power stations have open days?  Why have some power stations been closed?  Is there any on line resource that could answer these questions?

There is a constant program of modernisation of the grid infrastructure.  As some of the older power stations are de-commissioned, or as new gas stations com on-line, sub-station modifications have to occur, thats all.

As for why some power stations have been closed, thats a good question.  Most of our nuclear fleet are coming to the end of their design life.  Regulations are much stricter for the nuclear generators(thankfully) and it is pritty much written in stone that they will be de-commissioned as soon as they get to this point in their life.  This in itsself is pritty worrying as it would take about 10 years from brown field site to first synchronising a nuclear unit, i.e they need to start building today.

Drax is the newest coal station and its 20 years old.  The coal stations that have been closed have become un-economical for the generator to run in terms of efficiency or re-invest in.  It is worth noting that most of the coal fleet have already past their original design life.  My predecessors did a good job when they first designed these stations which were largely over engineered.

Nation Grid Company own and operate the grid in England and operate the grid in the UK.  Their site is pritty good, you can even see current grid demand and grid frequency in real time

http://www.nationalgrid.com/uk/electricity/

Some power stations do have open days but with recent green invasions, they are getting a bit nervous.  I could look into getting an OOF trip round Drax if anyone would be interested, can't promise though.

I would love to know more about how the generation is controlled and how stations are brought on line and taken off again to suit fluctuations in demand.

The method of balancing generation with demand is handled by the new electricity trading arrangements or NETA

http://www.bmreports.co

[Martin_1962]

Could children come?

[miked]

Yes, some regularly have school visits.  I'm on site next Wed / Thirs and will make some enquiries.   If it looks like a goer, I'll post in the Meetings and help days section.

[supermop]

Id be up for that! Theres also a gas power station in my town.... dono if they have open days or anything though.

[x25xe]

I would be up for a visit!! Sounds great and thanks for your post about my post if that makes sense.  Will follow those links with interest.  Thanks again really appreciate it.

[TheBoy]

Very informative post - thanks