Talk:National Grid (Great Britain)

message: User:Engineman  - Can't you find some published material on the transmission costs for wind power?  I appreciate this is an important subject, but the current claim seems to be based only on your own research.  The policy against original research does not only apply to factual information, but also to "arguments, ideas, data, or theories."  Thanks, Crosbiesmith 20:12, 15 November 2006 (UTC)
replies: text: It was only the last paragraph, the example concerning wind power, that I was questioning.  I didn't check the first part.  Was the paper read the 'UKERC Intermittency Report'?  Or was it some other paper?  - Crosbiesmith 19:47, 16 November 2006 (UTC)
thread_title: Cost per kWh of Transmission

message: In the losses section:
Fixed losses: 266 MW (consists of corona and iron losses; can be 100 MW higher in adverse weather)
Is iron a typo? The wikilink to iron doesn't make it any clearer. JimChampion 86.144.73.92 20:10, 5 December 2006 (UTC)
thread_title: Losses

message: Ive put back the estimation of transmission costs as being 0.2 p/kWh since it was removed without any explanation, discussion or counter argument.Engineman 21:58, 3 April 2007 (UTC)
thread_title: Transmission costs

message: “How much does it cost to shift electricity within the UK at semi market related prices?”
Bernard,
I am sure your facts are correct, but I don’t think your answer to my question is right.
Any generator will have to pay the access charges be they a new nuke or a wind farm and they will appear in the respective business case so don’t count.
All electricity that comes from a GSP no matter what its origin or distance has to pay the exit charges so don’t count either.
So the cost of getting it say 200 km  (surely 400 km) from a point in the HV near the large coal stations to the Wessex Area GSPs will be only the Triad charges, and as you say these are about 0.42 p/kWh,.
My error had been in averaging the Triad charges for the whole country who pay much less because they are nearer to the coal field power stations than Wessex which is why I got 0.2p
So it seems to me that the answer to the question “  how much  does it cost to shift electricity within the UK at semi market related prices over about 200 km (surely 400 km) is about 0.42 p/kWh.
Any advances anyone?
 Engineman 20:10, 25 April 2007 (UTC)
thread_title: Further comments on Bernard Quigg's points

message: There is another factor to consider here.  The total transmission cost is apportioned between generation and demand users on a 25/75 split (at least it used to be this).  The total costs are based on the transmission system usage at the three peak periods (i.e. triads).  Therefore if you are going to use triad payments as an approximate method to estimate the cost of transmission then you have to increase this by about 1.33 to account for the 25% contribution from generation that is hidden from your triad charges.
 
Just for reference, a new-build 275kV double circuit line will give a "firm" capacity of about 800MVA and a recent cost estimate is in the region of £1.2M/km installed.  This equates to a capital cost of £1.5/kVA/km or £300/kVA for the 200km reference.  This asset probably has a 40 year useful lifetime and so apply a reasonable discount rate to calculate the replacement cost of transmission.  This will give an upper end cost estimate.
 
Regards,
 
G    Engineman 17:35, 26 April 2007 (UTC)
thread_title: Comments from GB

message: Maurice
 
Firstly, Triad is locational and so you cannot extrapolate a southern triad into a national revenue.
 
Secondly, Triad is a return on the fixed costs of providing the wires and not a cross-subsidy.
 
Thirdly, BSUoS is a mix of mainly bought in transmission services (reserve, frequency response, reactive power etc). The exception is constraint costs, which may be considered a potential cross-subsidy for wires not-provided, except that wires not-provided, do not go into the asset base and earn a return anyway.
 
Finally, both BSUoS and Triad now cover for GB wires and services and not just NGET’s transmission system.
 
The final transmission price control Ofgem proposals for the 5-years starting in April 2007 give:
 
Total allowed revenue for TNUoS (NGET, SPT, SHETL): £1299m. This is 73% on supply and 27% on generation. This gives an average triad on peak day throughput of 60 GW (that was the peak for 2005/6) of £15.59/kW for demand. Generation TNUoS is based on TEC rather than peak day throughput but I am not sure they are interested in that. So approximating as £2.75/MWh
 
BSUoS incentive for 2007/8 is proposed at £440m (of which about £80m would be allowed for constraint costs). On a throughput of 344.8 TWh (2006/7 but I haven’t checked on allocation of losses in the BMRS figures for initial demand outturn on which I based this figure) then BSUoS is about £0.64/MWh on generation and on demand.
 
This gives £3.40/MWh on demand plus whatever comes through distribution on the T/D connection charge
 
I am also intrigued by their use of figures on diesel reliability. Outside demand control it is 85% but in demand control (presumably offered into standing reserve?) it is 50% due to load management in storms.
 
By the way, what is the concern about NGET revenues given that we have Ofgem attempting to keep them under control they will not be significantly different from what competition could deliver – i.e. that is what it costs to run the system and only limited fat can be carved out.
Rob
Engineman 17:38, 26 April 2007 (UTC)
thread_title: Comments from a leading UK consultancy

message: I've added a bit on the 28 May 2008 DCI but I'm know little about the technicalities and details appear to be scarce because they "want to maintain confidence in the network" as someone said on Radio 4 !? I presume that a DCI is a sensible criteria for inclusion although the last one occurred 4 years ago which seem rather too frequent ? The big one would presumably be the 1987 storm damage. Is it correct that too low a voltage is as damaging as too high a voltage ? What are the agreed bands ? They talk about frequency but do they mean voltage ? It would be nice to have a section on the emergency procedure, here's the link . Thanks -- John (Daytona2 ·  Talk ·  Contribs) 13:10, 31 May 2008 (UTC)
thread_title:  Major incidents 

message: These links are from the excellent  
http://energydiscussiongroup.wikispaces.com/
Engineman (talk) 14:12, 19 June 2008 (UTC)
thread_title: emergency procedures for loss of generationg capacity

message: The reference given for the section on transmission costs gives this document as a reference:
http://www.claverton-energy.com/download/147/ 
*Referring to page 9, the total transmission power is calculated at 2.7p/kwh.  
*The NGC portion of the figure is .71p /kwh.  
These figures are quite distant the .2p/kwh figure given in the article, so perhaps the passages needs updating to this 2008 document, or a source that supports the .2p figure should be found. -J JMesserly (talk) 23:02, 24 December 2008 (UTC)
replies: text: The .2p number seems ridiculous and a very minority opinion.  I've removed the section entirely.  TastyCakes (talk) 15:42, 8 April 2009 (UTC)
thread_title:  Transmission costs again 

message: I have one comment, and one question, both relating to the section on power losses on the transmission system.
1. The power losses in generator transformers are the responsibility of the power stations, not of the National Grid. Some power stations meter the power on the 275/400kV side of the generator transformer, so that the cost of any losses in the transformer is borne entirely by the power station, not the National Grid. Other power stations (mostly the ex-CEGB stations) have received a dispensation allowing them to meter the power at the generator side of the transformer. Where this is allowed, the power station is required to compensate the meters to account for the losses in the transformer. Whichever method of metering is used, the National Grid receives the power/energy that the metering has recorded. For this reason, the losses in the generator transformers cannot be considered a loss from the Grid.
2. On the subject of transmission losses, I wanted to follow up the references that the article provided. The "2005 Seven Year Statement", or "2005 SYS", is now unavailable on the internet. The 2011 SYS does not contain a section on the losses. Do you have any suggestions for how I should get hold of a copy of 2005 SYS? Are there any other references? I am particularly interested in the relative magniudes of the I-squared-R losses and the fixed losses of the Grid.
DickChambers (talk) 00:22, 4 June 2014 (UTC)
thread_title:  Transmission losses 

message: The "interconnects" sections states: "including for links to northern France". I am guessing that this means FOUR links, however without any reference I am loathe to make the edit. --Davidcx (talk) 23:31, 3 July 2014 (UTC)
thread_title:  For links? 

message: The History section includes "The growth by then in the number of electricity users was the fastest in the world, rising from three quarters of a million in 1920 to nine million in 1938.". That seems unlikely - I think that almost all properties (especially businesses) in urban areas, and many in rural areas, would have been connected by then.  Maybe the original author should have written "customers" rather than "users". 94.30.84.71 (talk) 08:54, 1 August 2020 (UTC)
thread_title:  Error in History? 

message: At the end of the history section it mentions that the T-pylons at Huntspill are the first non-lattice pylons. There are tower pylons located on Cambridge Science Park (https://commons.wikimedia.org/wiki/File:Pylon,_Cambridge_Science_Park_-_geograph.org.uk_-_774903.jpg) which have been in-place since, I think, the 1980's. They operate at 132kV but I don't know enough about the topic to know if they are part of the National Grid or not... Acey (talk) 10:51, 9 May 2022 (UTC)
replies: text: Thanks for pointing this out. I've changed the wording slightly. Regards Hallucegenia (talk) 12:41, 9 May 2022 (UTC)
thread_title:  History Section - pylon design 

message: Ok I give up, why do we say "per MW per hour" and not "per MWh"? I know that's what the source says, but it's a really odd way of expressing MWh and I think we should use the standard terminology. GA-RT-22 (talk) 04:14, 10 October 2022 (UTC)
replies: text: MWh is the measure of power delivered but this type of "reserve" purchase is a commitment to put plant on standby for X hours, ready to provide Y megawatts. The outcome is usually less than X times Y, and may even be zero MWh if the reserve is not called upon. Wire723 (talk) 14:47, 10 October 2022 (UTC)
replies: text: If that's for a reservation I guess it makes sense, but that's not clear from the text. GA-RT-22 (talk) 15:45, 10 October 2022 (UTC)
thread_title:  per MW per hour