Great Western Coffee Shop

Would require a rather expensive transformer to step down 25KV to 230 or 115 volts to power the fairy lights.
And they would dim whenever a train went past, because the nominal 25KV supply varies a lot more than does the normal domestic mains.
A regulated power supply could be used. Transformer intended for 33KV input, so as not to be overstressed when the nominal 25KV approaches 33KV. Nominal 240 volt output, which might average nearer 200 volts actual. Then a switched mode power supply that accepts from 90 volts up to 270 volts AC input, regulated output of 12 volts DC to the lights.

Surely you would want the fairy lights to dim as a train went past so as to not distract the driver.  If such a safety feature has been cleverly designed into the electrification system then I take back any criticism of NR I have ever made.  Presumably, diesel traction can be banned on safety grounds.

I hadn't realised that 25 Kv varied by too much around a 25Kv level.
How much does it wary by?
I presume there would be some sort of voltage thingy on board loco's to regulate the voltage back to a constant level for traction motors.
The National Grid tries to keep the voltage constant, but varies the frequency, does something similar happens here ?
W.E

The nominal voltage rail to contact wire is 25kV or for AT (auto transformer 50kV between contact wire and auto transformer feeder wire). There is a minimum voltage that trains can still run which is around the 16 or 18kV mark although the ECR will get an alarm from the (Grid) Feeder Station if it drops below 22 kV after 15 mins there is also a high threshold of around 28kV again after 15 mins

These values are from my memory so might be different but its the general principle

Traction units are specified to be able to operate at a fairly wide voltage range, this is important for instance on GWML if say Didcot ATFS was to drop off line the railway should still be able to operate a full timetable feeding from Kensal Green and Bathampton, traction power systems are designed to N-1, the N bit is the cheap bit the -1 is the expensive bit 

It's the other way around - National Grid has an obligation within its licence to control the frequency at 50 Hz ^ 1% - in other words, between 49.5 and 50.5 Hz. In practice, the operational parameters are set at between 49.8 and 50.2 Hz, a mere ^ 0.4%.

Frequency falls when demand exceeds supply and rises when the opposite occurs. It is managed second by second by adjusting supply and / or demand. It is for this reason that someone at National Grid watches TV in the main control room, ready to hit switches the minute the shouting dies down at the end of Eastenders. As a million kettles are filled, Dinorwig can be booted up to provide 1.8GW extra power within 15 seconds, before said kettles have been switched on. Or combined cycle gas turbine generators can be ramped up. Prayers can be said to the gods of wind to blow a little harder into the turbine blades of wind farms, although so far this has proven counter-productive. These gods tend to wait until demand is low before kicking off, necessitating constraint payments to shut down windmills. In extremis, a big electricity user such as a chemical works will be asked to shut temporarily, and /or small diesel generators will be started up around the country.

The domestic voltage supplied in the UK is nominally 240V AC, but is declared to be 230V AC +10% or -6%, so 216.2V to 253V is acceptable. Most modern equipment is designed to work perfectly well within these limits and beyond. The actual average is around 242V, more than is needed for most purposes, so wasting energy in use. In supply, however, it is more economic to supply electricity at higher voltages, as less power is lost in transmission. Doubtless similar principles apply to 25KV equipment, perhaps even with bigger margins for variation.

As I write, the frequency is 50.085 Hz according to gridwatch (http://www.gridwatch.templar.co.uk/). That gives a real-time summary of the mix of the power supply. Demand is low at 28.98GW, it being after 11pm on a fairly warm night. The frequency is the driver, and is constant across the National Grid. Voltage varies locally across the network according to local use and supply, but within the +10% / -6% limits.

Or so I understand -  I am not a professional, and am not entirely sure why frequency is so hugely important. Someone will explain!

Unless frequency is kept in close tolerance interconnection with other grids is impossible.  Try and connect supplies that are out of phase and it will not go well. 

I was once told about a power station which was refurbished and the phase meter was incorrect.  When he generator was connected to he grid it was 180 degrees out of phase.  The result was a big bang and the very heavy armature broke through the generator casing and out through the roof of the generator hall. 

You should have been a Physics teacher FT,N! That's pretty much how my excellent Physics teacher explained it many moons ago. Dinorwig's 'Electric Mountain' swinging into action to cover the 'TV pickup' is an impressive feat of science and engineering.

https://www.youtube.com/watch?v=SkIzKGot0Ss

It is somewhat disappointing though that plans for a second 'Electric Mountain' large pumped storage power station on Exmoor were never realised. That would be most handy today.

Oh and don't write of wind generation completely FT,N! Grid wide storage solutions for wind generation are feasible and there is proven technology. It just needs both government and the generation industries to realise that generation isn't the be-all and end-all. If we are to continue building wind generation (and we should, along with other generation methods which use a variable source of energy - sun, tide) then we need to research, fund and build storage too. Compressed air storage is likely the best candidate. The UK has a lot of abandoned mines that could be converted into such facilities.

Is Dinorwig really 1.8GW? Surely 1.8MW?

!.8 MW would not have much effect.  It is 1.8 GW.

Sorry - not really awake at 03:30!

Frequency control of the national grid is important for a number of reasons, though arguably not AS important as in years gone by.

Firstly some types of clock rely on the grid frequency for timekeeping and will become inaccurate if the frequency varies. Not just wall clocks etc. but also time controls for outdoor lighting or for heating controls. This is still important, but more and more clocks use an electronic timekeeping circuit and not the mains frequency.

Secondly a lot of industrial machinery is driven by induction motors the speed of which is closely related to the mains frequency. If the frequency is low then a whole factory is in effect slowed down and may produce say 0.5% less goods but still have the same labour and other costs. 0.5% was said to be many millions of pounds an hour in lost production over the whole country.
Less important these days as we have less manufacturing, and also a lot of modern machines use variable speed drives whereby the motor speed is controlled by an inverter and is not locked to the mains frequency.

Thirdly, a great deal of non-domestic lighting uses fluorescent or discharge lamps on copper/iron ballasts. If the frequency is low extra current is used, significant over the whole country, and still significant despite new installations tending to use electronic ballasts that are immune to frequency variations.

Fourthly, some specialist equipment including older types of audio and video recorders and cinema projectors  rely on the mains frequency to control to playback speed.
A 2 hour recording might run for 119 minutes or 121 minutes depending on frequency, and the pitch of music would be slightly wrong. Less of a concern with the spread of digital technology.

Finally the actual generation and transmission equipment is optimised for 50 cycles and may be less efficient or less reliable at other frequencies.

There is also a certain amount of national pride involved "my national grid has better frequency control than yours" The continental grid has much tighter frequency control than ours, a fact of which the French are inordinately proud.

Broadgage has listed the main uses that were sensitive to mains frequency. The increasing use of inverter and other electronic drives at all power levels might eventually eliminate all of those, but there are still reasons to control grid frequency. National Grid has a licence obligation to keep within that 1% limit "save in abnormal or exceptional circumstances", and I suspect the real importance lies with limiting those exceptionally low - or, worse, high - excursions. I can imaging some factory machinery being very embarrassed at being asked to run more than 10% overspeed.

I can have one more go at getting closer to the way the grid is managed, if you like.

If you have a big generator - say 500MW alternator - in your garden, just to run the Christmas lights, its frequency depends on the rate you turn it and it voltage on the excitation (the current magetising the rotor). If you connect it to the mains, both of these have to match the local grid, or else power flows. But not in quite the way you expect.

If your alternator tries to run too fast, it can't ever get more than a fraction of a turn ahead of the grid, and power flows to the grid depending on its "lead angle". Similarly, if you don't pedal hard enough, power flows back to keep it up to speed but lagging the grid by a few degrees. If the whole grid has more power going in (mechanical or purely electric, adding all generators) than going out (summing everything) then everything spinning locked to the grid speeds up together.

So rate of change of frequency is a sensitive measure of power balance, and it can be monitored anywhere on the grid. NG use it to control power balance for that reason. Note that the size of this spinning inertia keeps the system stable - if it was a lot smaller, the grid would accelerate a lot faster, and the feedback control would be more difficult - get it wrong and serious mayhem ensues.

So, what is the effect of varying the excitation? The generator tries to alter its terminal voltage, which is forced to be the same as the grid's local voltage. Well, no real power flows in or out - but reactive power (measured as MVAr) does. That's a bit mystical, but basically it's a necessary evil in AC systems, but too much of it is wasteful of resources and energy and, ultimately, it's dangerous. One if its effects to to cause local voltage variations, and NG control those by getting the big generators to vary their excitation so as to import or export the stuff (paying per MVArh of it).

AIUI (which is far less than other people who have already posted) 50Hz is the frequency used throughout Europe, including Russia, and North Africa, regardless of local distribution voltages, precisely so that the voles, anbarons and electric toads can be shunted across borders.

50 cycles is indeed the standard virtually throughout Europe, and does to an extent facilitate interconnection between neighbouring countries. There are however practical problems in interconnecting too large a geographical area and also problems in the operation of AC transmission lines of more than a few hundred miles.

Therefore many international interconnectors are in fact DC. The UK has interconnectors to France and to Holland, and others are planned. These all use DC thereby avoiding any need to synchronise the UK and continental systems despite both working at 50 cycles.

UK grid data may found via the link below, showing frequency, total load, import/export flows and from what sources electricity is being generated.

http://www.gridwatch.templar.co.uk/ (http://www.gridwatch.templar.co.uk/)

Thank you BNM, for those kind words. My physics teacher hated me, with some justification, and banned me from his lessons for the whole of the term prior to my O-levels. I got a Grade 1 just to spite him, and because I found the subject fascinating.


There was a pumped storage system in Lynmouth (http://www.visitlyntonandlynmouth.com/about/hydro-electricity) at the end of the 19th century. It worked well, but demand eventually outstripped it, and the Lynmouth flood finished it off. Plans for a much larger scheme were dropped because of cost. There are plans to build a new pumped storage facility in Snowdonia, although it will be a fraction of the size of Dinorwig.


I think storage of surplus wind energy is on the list, right after we have cracked fusion power (under research since 1920, jam promised tomorrow many times). At present, there is seldom any surplus wind power, and when there is, it tends to be because of a lack of transmission capacity. It gets stuck in Scotland, where routes out are in short supply. As the wind power available to the grid increases, the practical effect is a decrease in the use of the backup Combined Cycle Gas Turbine plants, such as Seabank and Didcot. Nuclear and coal plants operate best at flat-out top power, and gas largely compensates for the fluctuations in other sources, including wind. As coal plants are shut down, the amount of power generated by gas increases, being mitigated slightly by wind. As of this moment, almost two thirds of our demand is being generated by fossil fuels, with less than 5% coming from wind. I agree we need renewable energy and, when it becomes necessary, storage, but I reckon we backed the wrong horse and spent the money badly. A lot of people would disagree with me on that, usually at conferences in Brazil or Tokyo, or in the queue for subsidies.

And thank you broadgage, for the very clear explanation, and for helping me to understand for the first time why the interconnectors with other countries are HVDC, not AC. Iceland next! I have friends who work in providing generated power for big rock groups, and other things that fill a stadium, in places where the local supply frequency cannot be guaranteed. That can have massive effects on tuning of electronic gear. I didn't realise that wider industry had similar issues.

This may all seem off-thread - indeed it is - but I think it serves to provide an insight into the complexities involved in electrification of the railway. It is much more than stringing wires above the tracks, and plugging them into the supply. We now know that the frequency of 50 Hz is as good as guaranteed, but the voltage available at any given moment will vary considerably. Two trains on the same electrical supply may each need to draw - what? - upwards of 10 Mw each, causing fluctuations in voltage locally. If regenerative braking is involved, the flow of current will go the other way, and the voltage will have to increase to cope. The infrastructure and the vehicles involved will all have to be capable of managing such extremes, and often in less than ideal ambient conditions, without risking blowing an armature through a roof or similar.

Or so I understand.

According to Mystic Squirrel, the infernal combustion engine as a power source for road vehicles will be more-or-less dead in 20 years*. That means that quite soon there'll be a lot (https://www.teslamotors.com/en_GB/gigafactory) of surplus 8 to 10-year-old lithium-ion car batteries that have lost 30-40% of their capacity which, by definition still have 60 to 70% of their capacity - which is a lot. Grid storage, anyone? Plus all those electric cars plugged in to the mains could be used for grid storage too. And what about all those cars in station car parks? (https://www.theengineer.co.uk/electric-cars-could-provide-back-up-power-for-railways-claim-uk-engineers/).

* Flight of fancy? Maybe. Maybe not (http://fortune.com/2016/04/21/tesla-elon-musk-model-3-orders/).

Oh, researchers looking at system planning have indeed been casting envious eyes at all that on-line storage. But that's several steps ahead. For a start, the electronics isn't designed to push power backtheway.

So a first step would be to time the charging of all plug-ins (hybrid or pure electric) to when the power is most available. Currently most of them (few though they are) are plugged in immediately on getting home from work, so as to nicely overlap with the day's peak demand. As no-one has yet (AFAIK) provided any incenitve for people to shift this to overnight, we don't even know how willing they would be to do it.

North America is 60 Hz


There are other reasons for using DC cables as interconnectors, inductive and capacitive reactance is not a issue with DC as it is with AC; with AC you need to insulate to the peak Voltage and not the normally stated RMS value therefore the insulation at 400kV AC is greater than 400kV DC.  With DC you only need 2 conductors + and - with AC you need , DC systems do not need an earth reference AC requires an earth reference to discharge the induce and capacitive voltages, DC interconnector still needs to be monitored for first earth fault though

Not quite true - good old Economy 7 is an incentive, isn't it? That's why the neo-clarksonites can claim with some justification that electric cars get their juice from fossil fuels, as these power stations seem to like working nights.

Economy 7! I don't think it would be worth changing to that just for one car, though. I have heard plans to encourage us to put the washing machine and other appliances on before going to bed when we get smart meters, which sounds dumb to me. I'll put all my lights on instead - they are quieter.

By "this" I meant charging cars. But where Economy-7 survives I guess it would by a first step, at least if it's the real thing (i.e. all usage gets the night rate). But I though there was not much still in place, and are any new ones being put in?

The subject of that piece is Elon Musk, whose company SpaceX accomplished the major feat of landing the spent first stage of a Falcon rocket on a barge in the ocean. He said before then that the space transport business was less technologically challenging than the electric cars.

Aye. Ee's a birruvua lad, our Elon.

Interesting question, which set me off a-googling. My understanding from this is that the major suppiers do still offer Economy 7 tariffs, though they don't tend to advertise them. But there is a debate among the (growing!) EV community as to whether you should use dirty overnight fossil-generated power, or that which comes from your PVs during the day...

This would definitely be against the advice of the fire service.  If you have ever been woken in the middle of the night by a domestic appliance fire you would follow that advice!

I used to live in a second floor flat, and I received some adverse comment from my neighbours downstairs when I put my washing machine on during the economy 7 timeframe.  :P ::) :-X

Maybe what I said is now a bit out of date. BG for one offer an off-peak rate if you are prepared to have a smart meter (or already have one - of the right kind). Ecotricity, on the other hand, don't. But of course peak loading isn't inherently an energy supplier's issue, is it?

However Ecotricity offer 1,000 miles' worth of electricity per year to registered EV/PHEV owners (or over 2,000 if you're on their Economy 7 tariff). Which sounds pretty generous until you realise that that's only forty quid.

On the other hand, I now live in a detached house, with a dishwasher and washing machine positioned on the solid concrete ground floor - so I still tend to put them on overnight.  ;) :D ;D

Solid ground floor did not make any difference. Still could have killed us, ^50k insurance claim and 4 months without a kitchen. 

Oh and I know of at least one other person who has had the same experience. 

If you are asleep you are in more danger as you are absolutely relying on a smoke alarm to wake you.  At least if you are awake you have a better chance. Fire service were very clear in their advice never to leave washing machines, dishwashers and tumble driers on while you are asleep and not while you are out.  Some tenancy agreements also place liability on tenant if such an appliance is left on while unattended. 

Hmm.  :o

I was referring merely to the noise / vibration impact on my neighbours of my use of some domestic electrical appliances overnight.

In the flat, it was probably a bit of an inconvenience, to those living immediately below me - but in my house, now?

I'm puzzled as to how a domestic fire caused by any electrical appliance is more likely to occur overnight than it is during the day?

We have smoke alarms, which are active 24/7 ...  ::)

It's not that fires caused by domestic appliances are more or less likely overnight. It's the increased risk such a fire presents to people who are asleep when it breaks out.

Smoke alarms aren't in every home. And even when they are present, the time between activation and the rousing of slumbering householders could be the difference between life and death.

I'd never put my washer/dryer on at night just to save a few pence on a cheaper tariff.

Fair comment: we're actually not on any cheaper tariff overnight - and at least one of the three adult residents (and two dogs) in this household will be awake at any one time.  ::)

We are on economy 7 and find it a useful saving.
The washing machine is run during the off peak time, I was not aware of any advice not to run washing machines unattended and I am about to fit a smoke detector above it.

Several dehumidifiers are also used during the off peak hours.
In cold weather an electric heater is used for just the last 45 minutes of the off peak tariff in order to take off the early morning chill, before the wood stove is lit.

That's interesting. I vaguely remember reading about DC transmission lines in Siberia and Russia's Far East, where the lines are obviously very long indeed. But I've also read about a 50Hz transmission 'ring' around the Mediterranean. Neither particularly specific or informed memories though.

Much of Europe (plus some neighbours too) operates as a single synchronised 50 Hz grid, despite being controlled as separate national or smaller systems. The links between these are a mixture of AC and DC, and that's true of new ones being planned within this grouping - between Germany and Belgium, for example, using DC. There's a big network plandiagram (for those* who like that sort of thing) here (https://www.entsoe.eu/map/Pages/default.aspx). Mind you, I'm not sure it's accurate in all its details - it shows almost all the hydro schemes in Scotland as combined generation and pumped storage, which I think is not true.

* This may be a defining characteristic of members of this forum, I suspect.

Suspicion confirmed!

Plans are afoot for a HVDC link to Iceland, which generates all of its non-vehicular energy from natural sources, particularly geothermal heat, and has power to spare. It will be the longest so far into Britain. There is also a bi-directional link with the Irish republic. There were plans for a huge windfarm to generate power for the UK, which have not gone down well with the locals.

Some including myself doubt whether it is practicable or economic. 

Better to have an underwater pipe bringing all that hot water to the UK. I'm sure with a bit of insulation it'll keep nice and warm, and turn Lewis into a tropical paradise where it comes back up to land.   ;D

I think the length of the conductor would be nearly 250 miles. That isn't the shortest route to the UK, but it misses out Scotland because of the paucity of capacity there. The losses over that distance would be huge, but Iceland has spare electricity, generated with no environmental impact beyond building the plant, and we need some of that action. Iceland has a population not much more than half that of Bristol, and is looking to hydrogen production to replace petroleum fuels in vehicles, so giving it the possibility of entirely fuelling the country with no emissions - if you ignore the muck chucked out by Eyjafjallaj^kull in 2010, and others since. I shall be there next month, and shall ask questions.

Economy 7 and similar tariffs have had something of a change in purpose over the years. When we were a nation of nuclear power station builders, the idea behind them -and Dinorwig - was a way to store up all the excess power generated after we had all largely gone to bed. Nuclear and coal fired power stations are slow to start up or slow down, and work best at full pelt for as long as maintenance schedules permit. They would thus provide the base load - the minimum needed when UK PLC is ticking over. Other means, mainly gas these days, would supply the rest. Come 2016, however, and there isn't any spare nuclear or coal power as the stations have been closed. Add those to wind and solar power, and you still end up with around half of the base demand. Economy 7 has now become a way of balancing demand rather than storing excess power, with the grid in mind rather than the generators. Dinorwig is now the fine-tuning mechanism, able to supply significant power within seconds, and to shut down just as quickly without waste. The only way coal and nuclear stations (and early gas) could react to a sudden drop in demand was to pour their boiling water into the cooling towers without it being used to generated electricity - very wasteful.

Economy 7 could be described as an anachronism because of this, but a lot of small conurbations without access to mains gas still use storage heaters as a form of central heating (my cottage included), and for as long as that is the case and it still suits the power companies, it will continue.

Like Red Squirrel, I believe that in time the only use of oil in transport will be as a lubricant and possibly an insulator. Combined heat and power plants will be the norm in many cities, using either natural gas (much of it obtained from shale rocks) or small nuclear power plants, maybe using Thorium rather than Uranium as the fuel. Other heating appliances in homes will be highly efficient electric appliances, cooking will be by magnetic induction, which uses a third of the power burnt by a traditional hotplate, and developments in LED lighting will continue to drive down the price and power consumption. I have recently bought LED bulbs at ^9.99 for five which use 8W, but happily replace a 100W bulb. The light is warm and hardly different in quality from what we have been used to all these years - certainly better than the fluorescent energy saving bulbs.

250 miles would not even reach the Faroes - the routes being considered for IceLink are around 1200-1500 km. The Norway-Great Britain NSN, which is being built now from Northumberland to Norway, will be 720 km long. So it probably looks, to the guys building these things, like the next step up.

And to think I studied navigation for aviation! Looking at the various pieces about this, yes the shortest route would be 1000km, and that's to northern Scotland. Longer subsea cables have been built of course, but for communications. They don't have high voltage, and have boosters along the way. The capacity could be the equivalent of a new nuclear power station.

At least one of the contenders is offering to supply and finance the whole project, including new power stations in Iceland. There is plenty of spare hot rock there and, to confound Mark Twain's famous advice, new bits continue to appear. Presumably they will want a strike price that will pay for it, and it might not be beyonds the bounds after all.

Hang on a minute!  :o

Don't some of those Icelandic Banks still owe us (various UK local councils) a fortune in lost investments?

No I think they - or the Icelandic Government - have now paid it all back. 

Oh, right.  Thanks for that.  :P

So, giving lots more money to private power companies in Iceland is quite secure now, then?  ;) :D ;D

How a country of 330,000 people could have managed to clear a debt of billions of pounds is not clear - there would have been an awful lot of cod involved. The government was not required to stump up all of the money lost by other countries' institutions, but most of the debts have been cleared, and the Prime Minister even had a bit spare to invest offshore himself, some say.

The interconnector will be done, if it happens, on a similar basis to Hinkley C. A consortium of companies builds and operates the facility for an agreed number of years, supplying electricity at an agreed minimum price - the strike price. Although EDF has so far spent £2 billion on Hinkley C, the cost to the British taxpayer or consumer has been nil. We start paying £92.50 per MWh (2012 price - index linked increases will apply) only when it starts working. Incidentally, this price is high at the moment, but won't be soon. It is described by some as an "illegal subsidy". No-one has yet explained to me in satisfactory terms why this should be, where a strike price of £117 per MWh for offshore wind isn't.

If a 1200 Km HVDC interconnector can be made to transmit power at a strike price of £80 per MWh, it will look cheap. If it could be built for under £8 billion, it will be a bargain.An interconnector cable, the most expensive bit here, has no moving parts, and could last 50 years or more. It could be a goer if the finances can be made to work. The engineering isn't too big a deal. The cable, with an estimated 800 tonnes of copper per kilometre, could be laid in under 2 months, at least in theory, although the entire project will take around 7 years to complete.

And no, there won't be much Icelandic money involved. This sort of project appeals to big pension funds, needing a huge pile of cash upfront and delivering a steady predictable return. Iceland doesn't have an institution of that size.

As someone who declined the opportunity to take out those attractive Icelandic investments prior to 2008, it wasn't clear to me either.  I couldn't work out how a country of that size was able, not only to offer very attractive deposit accounts, but seemed to be buying up many UK companies as well. So I steered well clear. Unfortunately many others didn't, including local authorities, who seemed to think that an Icelandic bank was a secure investment.  Hmmm.....

I was lucky. I didn't have any money then. As they say, if it looks too good to be true, it probably is.

That made me think of Seasick Steve - "I started out with nothing and still have most of it left..."

I am resurrecting these two previous posts, simply in view of a news story from the BBC (http://www.bbc.co.uk/news/uk-england-oxfordshire-36932297):


Fair comment for your words of warning, ellendune, in view of this latest example.  CfN.  :-X

The most frequently encountered problem is that of the unemptied fluff filter. Add to that the drier stopping before the last few minutes of the programme, which actually cools it down, and you have some explanation as to why fires do seem to occur in tumble driers with some regularity. Properly maintained and used, they are perfectly safe, but not everyone reads the instruction manual from cover to cover.

It happened to the late Sir Terry Wogan, as this Telegraph article (http://www.telegraph.co.uk/news/celebritynews/3701840/Fire-at-home-of-BBC-presenter-Terry-Wogan.html) explains.

Dishwashers do not have fluff filters

I shall use a dishwasher to dry my clothes henceforth.

I've heard that you can cook salmon (and presumably other things) in a dishwasher. So perhaps it's time to try washing up in the oven.

I myself have cooked salmon in the dishwasher it works best with a little white wine some sliced lemon a grind or two of white pepper also the salmon cooks best in a vaccum sealed freezer bag !!!.... ;D

By the way, this BBC report (http://www.bbc.co.uk/news/uk-33124925) from last year repeated the figures that Which? got via an FoI request, and which were behind the numbers being quoted:

I'm not sure what got counted as a "fire" - possibly just a fire service call-out. Also, you'd really like to know the numbers of these out there as well - I'd guess at more washers than dryers and evern fewer dishwashers, which makes you wonder which are the most inflammable probabilistically. 

I'd have said more dishwashers than dryers, but whichever, clearly the figures make little sense unless they can be related to total numbers of those appliances. It might also be informative to know the severity of fires caused by different appliances, if such a thing can be categorised.

Interesting that deep-fat fryers don't appear on the list: one would imagine them to be a frequent culprit.

Purpose made electric deep fat fryers are relatively low risk since they are fitted with thermostats that should prevent the oil reaching a dangerous temperature. Any overflowing of the oil is unlikely to be a fire risk since it goes onto the worktop or the floor and not onto a flame or hot element.

The greater risk is deep fat frying in an ordinary pan atop a gas or electric cooker, nothing but human observation then prevents the oil from becoming dangerously hot. Also if too much oil is used, or if the food being fried is wet, then the oil is apt to overflow onto a gas flame or red hot electric ring.

True (and I once put out a fire in a neighbour's kitchen due to that). But as those figures are only for "fires caused by faulty appliances", such fires wouldn't be included.

A fireman friend held the view some years ago that it may be cost effective to hand out basic electric deep fat fryers free in exchange for the chip pan. A significant number of fires he dealt with at weekends were those where the man of the house, returning from the pub, decided to make some chips for supper, and fell asleep whilst waiting for them to cook. The electric deep fryer is more solution than problem. Such fires are almost unheard of these days, which may also be down to the ubiquity of fast food outlets.