For technical discussions about electricity, electrical equipment with particular emphasis on safe and compliant installations.
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kenneal - lagger wrote:
I'm sure that Germany checked with the Russians that their gas supply wouldn't be cut off before they expelled all four, was it?, Russian diplomats.
That's why the Germans built the Nordstream pipeline. A dedicated gas supply just for Germany direct from Russia without having all the pipeline transit issues.
Interestingly the Swedes thought that the Russian ships putting that pipeline through their territorial waters did rather a lot of 'surveying' just for a pipeline.
Last edited by BritDownUnder on 02 Apr 2018, 09:33, edited 1 time in total.
BritDownUnder wrote:Interesting story in the Daily Mail about Russia being interested in undersea cables (mainly fibre optics apparently). If they knocked out the HVDC connections to France and Holland they could slice off 3GW of generation (as the UK mostly imports) at a stroke.
Of course they could just have a few 'gas pipeline problems' and achieve the same result by cutting off Europe's gas supply.
The loss of electricity imports at times of high load and little wind could certainly lead to rota power cuts, but nothing worse.
For most of the day we could manage without imports, and have done so when the interconnector is broken.
In the evening peak, we could manage without imports unless demand was unusually high or wind power unusually low.
The UK/France interconnector is not that reliable, and indeed is restricted to 75% load at present.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
BritDownUnder wrote:Interesting story in the Daily Mail about Russia being interested in undersea cables (mainly fibre optics apparently). If they knocked out the HVDC connections to France and Holland they could slice off 3GW of generation (as the UK mostly imports) at a stroke.
Of course they could just have a few 'gas pipeline problems' and achieve the same result by cutting off Europe's gas supply.
The loss of electricity imports at times of high load and little wind could certainly lead to rota power cuts, but nothing worse.
For most of the day we could manage without imports, and have done so when the interconnector is broken.
In the evening peak, we could manage without imports unless demand was unusually high or wind power unusually low.
The UK/France interconnector is not that reliable, and indeed is restricted to 75% load at present.
You are correct but the lost HVDC power still has to made up from somewhere more expensive to produce. In the energy market it just happens that this power is cheaper than CCGT and is a higher priority in the order of merit for power supply. From what it looks like the UK HVDC inter-connectors to France and Holland are basically baseload power. The problem would be that an extra 3GW would have to be found continually and not just at peaks. it could probably be done but someone would have to pay for the extra gas generation and we all know where that gas would have to come from.
The Basslink HVDC cable between the Australian mainland and Tasmania is currently out. Damaged by a contractor in the converter station apparently. Last time it was out it took 6 months to repair. No-one has made public the exact cause of that cable failure.
I suspect that it would be harder to vandalize a HVDC cable and not be found out as they go through quite shallow territorial waters of the North Sea compared with trans-oceanic optical fibre cables. The actual act of damaging would be quite easy if a little dangerous - just use a submersible to drill a hole through the insulation into the conductor should do the trick.
BritDownUnder wrote:
I should stop giving Mr Putin ideas.
I wouldn't worry about the Russians, they have already had all the evil ideas you or I could think of. It's the immigrant and home grown amateur terrorist I worry about giving a workable idea they may not have thought of by themselves or picked up on a radical web site that the powers that be monitor.
Fortunately these newbies don't as a rule have submarines at their disposal.
BritDownUnder wrote:
I should stop giving Mr Putin ideas.
I wouldn't worry about the Russians, they have already had all the evil ideas you or I could think of. It's the immigrant and home grown amateur terrorist I worry about giving a workable idea they may not have thought of by themselves or picked up on a radical web site that the powers that be monitor.
Fortunately these newbies don't as a rule have submarines at their disposal.
I agree and think the Russians quite possibly have thought of all this before. Mind you the US had a few good ideas too in the past, for example attacking substations with missiles that spread meshes of carbon fibres over all the electrical conductors during the First Gulf War. Shut them down for weeks. Or during Soviet times allowing the KGB to steal 'doctored' software from a Canadian manufacturer of Gas pipeline equipment causing Soviet pipelines incorporating this malware to blow up.
As for the amateurs, yes drilling into a 300,000 Volt cable is only for those intent upon the path of martyrdom.
No close and therefore dangerous approach to a subsea cable is needed for sabotage.
A number of failures have been caused by the dragging anchors of ships, it would be easy to engineer more such accidents.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
I was thinking more along the lines of a stealthy undersea attack with the cable owners blaming the outage on a cable insulation failure as the result of the possible method I mentioned above rather than an obvious 'accident' caused by a ship dragging anchor. I am pretty sure that the ship owners would be made to pay in such circumstances and in the well monitored North Sea they would be found out fairly quickly.
Owners of the Australian Basslink cable claimed failure was due to a rupture in the cable the size of a thumb or a drill bit from an undetected underwater craft maybe? I suspect they said that for legal reasons. More realistically it was damage done during cable laying or construction.
I am not really suggesting this would happen but given sufficient malice on someones behalf it could happen. Given the ill-will going about at the moment I am sure that such ideas are being thought about. It goes to show how complex, fragile and, if you excuse the pun, inter-connected our society has become.
BritDownUnder wrote:I was thinking more along the lines of a stealthy undersea attack with the cable owners blaming the outage on a cable insulation failure as the result of the possible method I mentioned above rather than an obvious 'accident' caused by a ship dragging anchor. I am pretty sure that the ship owners would be made to pay in such circumstances and in the well monitored North Sea they would be found out fairly quickly.
Owners of the Australian Basslink cable claimed failure was due to a rupture in the cable the size of a thumb or a drill bit from an undetected underwater craft maybe? I suspect they said that for legal reasons. More realistically it was damage done during cable laying or construction.
I am not really suggesting this would happen but given sufficient malice on someones behalf it could happen. Given the ill-will going about at the moment I am sure that such ideas are being thought about. It goes to show how complex, fragile and, if you excuse the pun, inter-connected our society has become.
Oh yes though it is not a new idea. I had a school mate (much smarter then I) that got a job with some government agency back in the seventies figuring out how to tap into the communications in fiber optic cables without the signal being disturbed or the tap detected. Point being to figure it out before the Russians did. I don't know how that came out of course but he is still employed by the feds so you might expect he figured it out for them.
I have noticed that the UK has had some very good days of solar generated electricity in the last few weeks around the summer solstice. The solar itself is dwarfing the load generated by the pumped storage schemes even at the times the pumped schemes kick in. A pity that the UK government saw fit to 'disincentivize' solar in the last few years after a good run of installations. Over 8GW at the peak for each of the last seven days.
I think this number could be easily doubled without affecting base-load requirements at all.
I see also that the French inter-connector imports have halved for the last week or so.
Here is my reasonably pessimistic forecast of evening peak availability and demand for the coming winter.
coal---------------6Gw, 2 less than last year due to closure of Eggborough
nuclear-----------6.5Gw, same as forecast last year, it has previously been this low.
CCGT-------------25Gw, allows for breakdowns
wind--------------1Gw, it will probably be a lot higher but only 1 can be counted on
biomass----------2.5Gw, 1 more than last year, based on extra capacity
pumped/hydro---2.5, same as last year.
net imports-------1 Gw, as last year,
OCGT/Diesel------0.5Gw, as last year.
About 44Gw in total. Well below a pessimistic indicated maximum demand of 51Gw.
Note however that I have assumed the "worst reasonably foreseeable" output from each type of plant.
I consider each forecast to be reasonable if considered alone, but we would be very unlucky indeed if ALL the worst estimates were realised at the same time.
Last edited by adam2 on 04 Oct 2018, 17:50, edited 1 time in total.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
Here is my reasonably optimistic forecast of winter evening peak capacity and demand.
coal------------------8 Gw, it regularly reached 10 last winter but 2 has closed.
nuclear---------------8 Gw, fairly regularly achieved in the past.
CCGT----------------27 Gw, achieved last winter.
Wind-----------------1.5 Gw, fairly reliably reached that last winter.
OCGT/diesel---------0.5 Gw, as last year.
Net imports----------2Gw, achievable with a bit of luck.
pumped and hydro---4Gw, cant be sustained but helpful for the high peak.
Biomass --------------3Gw, has recently been that high.
Or a total of about 54 Gw which is in excess of a reasonably optimistic peak demand of 50 Gw.
Wind power will probably be several times more than the forecast 1.5 Gw, but based on last years experience, and allowing for more wind capacity having been built, 1.5 Gw is the most that can be counted on during winter.
OTOH my estimate for coal and for biomass may be a bit optimistic, each figure considered alone is probably reasonable, but I suspect that the extra 1Gw of biomass capacity is converted from coal.
So the total for coal and biomass might be 10 Gw and NOT the 11 Gw that simple addition would suggest.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
adam2 wrote:No, the stated figures refers to the electrical output, 1Gw is 1Gw whether produced from coal, or from biomass.
I don't want to start a long or acrimonious debate about it, And you maybe right, but I can't see how say a one megawatt coal plant could switch to wood or some other bio fuel and still produce one megawatt of power. You would have to rebuild it from stock yard to smoke stack to account for the increased volume needed to obtain the same BTUs in a given volume of coal.
Maybe they run it on higher settings (if the machinery is capable) or for more hours a day but being a very skeptical individual I'd need to see the actual output figures to swallow that one.
Most UK coal burning power plant burn pulverised coal, this is blown into the furnace by compressed air and burns almost instantly.
It is a relatively simple matter to blow a larger volume of wood chips into the furnace instead of coal.
Steam is raised in the same way and the steam turbine and alternator will have the same output, these components do not "know" what fuel was burnt to produce the steam.
Oil is burnt during initial lighting up, until a stable flame pattern from the coal or wood chip fuel results. No oil is used in normal operation, only for starting.
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"
