The Future of Power Generation in Great Britain
Discussion
Gary C said:
LongQ said:
Note
that will provide frequency response to help keep the grid frequency stable at 50 Hz and maintain operability.
In other words they are putting something in place at source that stops the fluctuating output causing problems with the distribution network. Something that established non-wind powered turbines have in place already by the nature of their designs
We have some droop on large existing generation, however AGRs run at about 25% so their frequency regulation is almost none existent (infact because most gas circulators slow when the frequency goes down, the output can actually fall).that will provide frequency response to help keep the grid frequency stable at 50 Hz and maintain operability.
In other words they are putting something in place at source that stops the fluctuating output causing problems with the distribution network. Something that established non-wind powered turbines have in place already by the nature of their designs
Edited by LongQ on Thursday 3rd August 20:32
It's the embedded generation that's making life hard for generates and the grid. Demand goes up and down unpredictably, far to fast for some large generators.
If a wind farm could have embedded storage that is instantly demand controlled, that would help.
(Cost meaning direction operational costs and ecological costs for mining the raw materials and competing for supply in an artificially induced market overly influenced by willy waving politicians.)
turbobloke said:
A one-off? Non-viable at scale.
Why energy storage is a dead-end industry:
http://energystoragereport.info/eroi-energy-return...
Very Conveniently ignoring the linked follow up article from the same sourceWhy energy storage is a dead-end industry:
http://energystoragereport.info/eroi-energy-return...
Why energy storage is (not) a dead-end industry
http://energystoragereport.info/eroi-energy-return...
Paddy_N_Murphy said:
turbobloke said:
Gary C said:
If a wind farm could have embedded storage that is instantly demand controlled, that would help.
A one-off? Non-viable at scale. Why energy storage is a dead-end industry:
http://energystoragereport.info/eroi-energy-return...
Energy storage cannot solve the problem of intermittency of wind or solar power:
https://bravenewclimate.com/2014/08/22/catch-22-of...
Basic stuff from Weißbach et al.
Anyway as to your latest silly question...
I can't say but you should know -what's the answer?
turbobloke said:
Paddy_N_Murphy said:
turbobloke said:
Gary C said:
If a wind farm could have embedded storage that is instantly demand controlled, that would help.
A one-off? Non-viable at scale. Why energy storage is a dead-end industry:
http://energystoragereport.info/eroi-energy-return...
Energy storage cannot solve the problem of intermittency of wind or solar power:
https://bravenewclimate.com/2014/08/22/catch-22-of...
Basic stuff from Weißbach et al.
Anyway as to your latest silly question...
I can't say but you should know -what's the answer?
After privatisation, ngc got very worried about frequency control, and especially its effect on large steel furnaces such that we spent a fortune on fitting dump tubes into our condensers to allow steam to bypass the turbine to give an instant increase in generation if a large loss was experienced (particularly a reactor trip at sizewell)
The wind farms and solar (especially embedded) generation is making both frequency an voltage control very hard. We used to get gen transformer tap instructions every morning to increase voltage, then every night to decrease, regular as clockwork. Now we get them at all times of the day as ngc try to cope.
Any storage on variable sources would help.
As to tech, I think we are investing in a atmosphere liquification storage plant were excess generation is used to compress and liquefy air, then vaporise it to drive a generator when required. An interesting none battery idea, but not looked it to it in any detail.
Edited by Gary C on Saturday 5th August 16:25
Ali G said:
Still struggling to understand why Fission is not the answer.
Since it is.
Do you mean fusion ! If soSince it is.
Cause we can't make it work "
If you mean fission, then, people don't like it, it is expensive, and it takes years to build anything.
A nuclear power station has become such a emotive thing. We can't pretend anymore that it's perfectly safe.
They are very expensive to build and maintain.
Small modular reactors may be the answer but maybe a terrorists dream having lots of little ones dotted around the country, where standards slip and regulators become massively stretched trying to keep on top of them all.
Also, security of fuel supplies and costs, now if we went fast breeder, we have enough depleted uranium to last years, but they cost a fortune in backend costs reprocessing the fuel to extract the plutonium.
Thorium reactors are interesting, but we need to spend a LOT of money researching an designing and companies are not interested in spending, needs a government to do that.
Just wish we would stop burning all that gas just to make electricity.
Oh well, time to go to sleep, on nights in charge of a nuclear power station tonight
Edited by Gary C on Saturday 5th August 16:40
Edited by Gary C on Saturday 5th August 16:44
s2art said:
Ali G said:
Still struggling to understand why Fission is not the answer.
Since it is.
Well, it would be if our civil servants and politicians were capable of evaluating a suitable bid/design. Hinckley point is the clue.Since it is.
Unable?
Wash your mouth.
SantaBarbara said:
There are plans to erect many off shore wind farms in the Irish Sea
Wonderful.Wind energy developments have significant negative impacts on bat populations (Voigta et al 2012). Both Bat Conservation Ireland (Bat Conservation Ireland, 2012) and the Bat Conservation Trust consider that that bat mortality due to wind turbines is a serious issue in Ireland and Britain.
"Bats and their habitats need to be considered carefully during the planning, construction and operation of onshore wind farms. But could offshore wind farms also pose a risk to bats?" (Dr William O'Connor, a bat man)
The answer is yes after a rare variety of pipistrelle bat fitted with an indentity ring was found after completting a 600km flight over the sea from Bristol to the Netherlands. Until that point scientists hadn't known whether British bats migrate over water or not, given they're too small to be fitted with the type of satellite tracker usually used in such studies. There's also evidence that non-migratory bats can fly offshore to forage on insects blown out to sea.
Onshore turbines wreak havoc with birds of prey and bats. I recall posting info in another thread from a Spain-based study which showed that over 600 bats are killed per turbine per year. I'm not convinced that the UK will be far outside that range if at all. IIRC we have more than 4,000 onshore turbines in the UK, which are killing over 2 million bats per year using the Spain study stats. Adding offshore bat fatalities would be unwelcome to say the least, but in the current climate where so-called wildlife organisations are in thrall to climate claptrap and sit on hands over windespread deaths of birds of ptey, the lack of incentive to discover exactly how many of these rare and protected mammals are being killed by offshore green white elephants means we may wait for a long time to find out (if ever).
Edited by turbobloke on Saturday 5th August 17:41
Paddy_N_Murphy said:
V8 Fettler said:
Paddy_N_Murphy said:
V8 Fettler said:
V8 Fettler said:
Paddy_N_Murphy said:
V8 Fettler said:
What is the minimum utilisation ratio for offshore to date? This can be used as an indicator of the capacity of the required back-up systems.
To date ?What a stupid question, and irrelevant.
See second word of thread title
(And congrats for repeating a question asked by yourself before to needle a point vs. Contribute)
You seemed to think it's an obvious value.
(And again - why are you using your own estimates, or guesswork? Go off and find the answer if you feel strongly)
I can see you're getting annoyed, so I'm obviously on the right track.
Paddy_N_Murphy said:
V8 Fettler said:
Paddy_N_Murphy said:
V8 Fettler said:
V8 Fettler said:
Paddy_N_Murphy said:
V8 Fettler said:
What is the minimum utilisation ratio for offshore to date? This can be used as an indicator of the capacity of the required back-up systems.
To date ?What a stupid question, and irrelevant.
See second word of thread title
(And congrats for repeating a question asked by yourself before to needle a point vs. Contribute)
You seemed to think it's an obvious value.
(And again - why are you using your own estimates, or guesswork? Go off and find the answer if you feel strongly)
I can see you're getting annoyed, so I'm obviously on the right track.
Gary C said:
After privatisation, ngc got very worried about frequency control, and especially its effect on large steel furnaces such that we spent a fortune on fitting dump tubes into our condensers to allow steam to bypass the turbine to give an instant increase in generation if a large loss was experienced (particularly a reactor trip at sizewell)
Tech question please;Why are furnaces sensitive to frequency? Surely that's a pretty 'dumb' load that just needs grunt rather than a nice clean precise 50hz supply.
What other loads are sensitive to frequency - the only obvious ones to me would be electric motors, what critical effect would 1/2hz drop actually cause? (i know it rotates slower, but is that really the end of the world?)
IT equipment all uses swiched mode power supplies - so I can't see how a variation in frequency would make any difference?
Finally - you mentioned dump tubes, can I assume that this sort of alleviates back pressure allowing the turbine to spin faster to correct frequency?
thanks..
eliot said:
Tech question please;
Why are furnaces sensitive to frequency? Surely that's a pretty 'dumb' load that just needs grunt rather than a nice clean precise 50hz supply.
What other loads are sensitive to frequency - the only obvious ones to me would be electric motors, what critical effect would 1/2hz drop actually cause? (i know it rotates slower, but is that really the end of the world?)
IT equipment all uses swiched mode power supplies - so I can't see how a variation in frequency would make any difference?
Finally - you mentioned dump tubes, can I assume that this sort of alleviates back pressure allowing the turbine to spin faster to correct frequency?
..
I don't think the furnaces are sensitive to frequency, but they are huge loads, and are tolerant to power loss. As a result, they are commonly fitted with low-frequency load-shedding controls, so that they disconnect automatically in the event of a large grid imbalance. However, if the trip system operates too frequently, the disruption to business and loss of production may be intolerable to the furnace operator.Why are furnaces sensitive to frequency? Surely that's a pretty 'dumb' load that just needs grunt rather than a nice clean precise 50hz supply.
What other loads are sensitive to frequency - the only obvious ones to me would be electric motors, what critical effect would 1/2hz drop actually cause? (i know it rotates slower, but is that really the end of the world?)
IT equipment all uses swiched mode power supplies - so I can't see how a variation in frequency would make any difference?
Finally - you mentioned dump tubes, can I assume that this sort of alleviates back pressure allowing the turbine to spin faster to correct frequency?
..
Frequency sensitive loads are basically rotating machines. Motors and generators. For most purposes a 1% drop in speed (0.5 Hz) may be acceptable. However, very large machines, such as multi-MW motors may have vibrational resonance close to, but not exactly, 50 Hz. Similarly, large turbine generators have a similar property, in fact, it is often worse due to the large number of connected rotating components (turbine discs of various diameters, etc.), hence operating a turbine off-frequency while under load is highly inadvisable (typical limits might be +/- 1% indefinitely, down to 1 second at +/- 6%).
There are also some secondary effects on power generators. New designs of CCGT generators tend to use a single shaft synchronous design, rather than a free power turbine. A drop in frequency will therefore reduce the speed of the compressor, and therefore reduce the air flow and therefore power output. For AGR plants, as said above, the gas circulators may be synchronous. If the mains frequency falls, the circulators slow, the core temperature rises due to reduced coolant flow, doppler effect from the core temperature alters the interactions between neutrons and uranium atoms causing the chain reaction to falter and reactor power output to fall.
The dump tubes allow steam to bypass the turbine, and go straight to the condensers. Under normal operation, the bypass valve would be closed, and all steam would go to the turbine. However, if frequency instability is anticipated, some of the steam would be diverted to the condensors instead of the turbine. This would reduce turbine output, which would need to be made up by another plant. However, in the event of a sudden drop in frequency, a reserve is available, by bringing the steam currently going to the condensor and diverting it back to the turbine. This allows the plant to respond to changes in grid condition, without allowing the reactor to operate in steady-state at full power, unaffected by the change in electrical power output.
SantaBarbara said:
Pumped storage like they have in North Wales would be a good idea
Surely they could build more of them in Scotland?
Try this:Surely they could build more of them in Scotland?
http://euanmearns.com/?s=pumped+storage
Notably the article about Loch Ness and the Bingham Canyon project in the USA.
There's another article somewhere about the potential for turning all of the Scottish Highlands into a Hydro scheme and how it would be a long way from providing an answer even then. I'll post a link if I find it.
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