Low mains voltage

[martin_wynne]

All this energy, four times a day (twice in, twice out), and we are an Island with many suitable estuaries, Severn, Morecambe Bay etc.

 

Other countries with a much shorter or non-existent coastline must think we are crazy not to be taking advantage of such a natural resource. It's surprising they don't tell us where to go when we come begging for their spare capacity on a mild autumn day.

 

Martin.

[4630]

. 

[trisonic]

New York City is considering putting turbines underwater in the East River (which links the sea north of Long Island - about 150 miles long -  with the sea south of Long Island via the New York harbor) and has a very strong tidal flow. They’d be on the bottom and not a threat to shipping.

 

Best, Pete.

[Fat Controller]

I imagine they can spot a mug when they see one Martyn.

 

Consquently, I guess we all have to pay through the nose because the country can't chooses not to be self reliant for its electricity generation.

 

As a matter of interest, perhaps someone in the know can let me know how the electricity passed through the interconnector is paid for.  I assume there isn't a bl**dy great meter at each end (!), but there must be a mechanism to apportion the cost accurately.

I woukdn't bet that there's not some very big meters on either side. Apparently, Eurotunnel are installing a second DC interconnector from France (I believe there's already one from Belgium to the UK); if I meet one of the people involved, I'll ask how it's metered.

[4630]

.

[Revolution Mike]

Agree Clive, the non replacement of closed and soon to be closed coal fired plant is most scary. I also think clean burn coal should have been looked at more here in the UK. Too late now probably. Germany is building new lignite (dirty coal) powered plants as I type. The generators from the recently demolished Didcot coal plant were exported to - Germany - for use in a new coal plant there.

 

Don't forget that on a freezing cold winters evening, it's peak load for both electricity and gas. Gas loads are also shed at times of peak demand - known as interuptibles. Large industrial users usually with in house alternative energy supplies that can be instantly turned on (dual fuelled oil / gas burners etc). This has saved our (gas industry's) bacon more than once in cold winters.  So, I hope the current gas fired power stations have agreed fixed and secure supplies in peak times over winter, or it will really be lights out.

 

Can we put to bed some these myths that keep appearing everytime we talk about power generation?

 

The idea that we haven't replaced any generating capacity is just not correct - renewables, biomass and most importantly gas plant has all been built (and continues to be).

 

Clean coal (pre and post combustion) has been looked at almost everywhere and no one has found good ways of making it work at any sort of economic price.

 

Germany is building lignite plants because it panicked and shut its nuclear plants and has no choice in the short term.

 

The National Grid NISM is unusual but was easily solved by calling on additional supplies (of which there were clearly plenty). Either someone at NG cocked up or more likely there genuinely was a problem at a large plant which reduced the supply margins temporarily.

 

IIRC there's at least one high voltage link to the Continental grid, so purchase of power elsewhere shouldn't be too much of a problem, provided said link(s) can handle the extra load.

There are at least 2 electricity interconnectors (one to France and one to Ireland) and at least one more planned.

 

And provided they have some to spare in mid-winter. I'm not clear why we should be relying on our neighbours to bail us out.

It is part of the benefits of the EU ie greater levels of interconnection of the grid systems means more resilience.

[raymw]

Many years ago, as an 'award' I was given the opportunity of either going on a weeks 'Outward Bounds Course' or a trip on the 'Dame Carolyne Haslett'  http://www.aberdeenships.com/single.asp?index=101541 . She had just completed the laying of the first HV DC channel link https://en.wikipedia.org/wiki/HVDC_Cross-Channel and had been reinstated to being a flatty. Iirc she was actually taking coals to Newcastle, from the Thames.

A few years later, unrelated, part of the National grid was out for maintenance, and then there was a fault somewhere in the Canterbury area, ( fast growing willow had caused an arc between, most likely the 400kv line and ground), which took a few days to repair. In that time, the whole of the South West of England, and iirc part of South Wales was supplied by Hinkley for three days or so. I remember the dg of CEGB  speaking with pride about that incident at the fancy new offices at Bedminster Down.

 

And then there were the visits to Berkeley Nuclear Labs some really clever folk there. Personally, I feel that the supply industry should never have been privatised, I left then, early retirement (49yrs old) because I could imagine safety/reliability problems ahead. However, afaik, much of my imagination did not come true, luckily.

[Nearholmer]

Yes, meters. Its not the meters that are big, but the devices which allow them to sense current and voltage.

 

Some of what look like actual facts in The Times today (p14): West Burton and Rugeley Gen Stations unexpectedly out of action, and a failure at Fiddler's Ferry, combined with the lack of wind,mare reported to be what lay behind yesterday's call for capacity.

 

K

[Metr0Land]

There are at least 2 electricity interconnectors (one to France and one to Ireland) and at least one more planned.

 

It is part of the benefits of the EU ie greater levels of interconnection of the grid systems means more resilience.

 

 

Err you don't have to be in the EU to have a cable to adjacent countries?

[raymw]

I would hope that any short term large voltage variation would be localised, usually due to faulty tap changer at the 33kV substation, or some other fault. No point in measuring voltage with the average digital meter (whatever that would mean. You need to measure, with the appropriate equipment at the meter position (not to say you can't get a ball park idea, or see if it is less or more than before).

[Revolution Mike]

Err you don't have to be in the EU to have a cable to adjacent countries?

No you don't but it helps if you have signed up to "common" standards and commitments to help each other.

[Metr0Land]

No you don't but it helps if you have signed up to "common" standards and commitments to help each other.

 

But you don't have to be in the EU to be part of eg CEN standards, which apply across Europe and to countries queueing up to join and/or EFTA countries etc.  

[New Haven Neil]

I noticed Peel diesel station fire up yesterday lunchtime - you may find it funny, but we have an interconnector too, and often give a bit of power to the UK when they need it.  Our main power plant is gas, but we still have diesels in Douglas and Peel.  It earns easy money apparently, as we can generate more cheaply.....despite imported fuels!

 

 

creative commons licence

[Revolution Mike]

But you don't have to be in the EU to be part of eg CEN standards, which apply across Europe and to countries queueing up to join and/or EFTA countries etc.  

I'm not talking about CEN standards though, I'm talking about the EU Directives on interconnection and interoperability etc and the forthcoming Energy Union along with the concept of an internal market/EU.

[New Haven Neil]

We're not in the EU or the UK.....but we give power to the UK.

[APOLLO]

We won't be in the EU either in a year or so. I reckon the EU will collapse well before we Brits get the vote.

 

Thanks for the free electricity Neil !! Much appreciated !!.

 

Brit15

[28XX]

Political Union is not a prerequisite to technical cooperation or trade between countries.

[Revolution Mike]

I reckon the EU will collapse well before we Brits get the vote.

 

No chance. I think you seriously underestimate the political will of most of the EU!

[Revolution Mike]

Political Union is not a prerequisite to technical cooperation or trade between countries.

 

No one is talking about political union (the Treaty of Rome actually talks about ever closer union with various aims eg the internal market) despite what some British politicians and media claim.

[Ozexpatriate]

The BIG problems start when the FREQUENCY drops away from 50Hz - many vital bits of kits NEED to run at that frequency and lives can be put at risk if it drifts so the National Grid is setup to sacrifice voltage levels if necessary.

The principal parameter which grid are interested in is indeed frequency, whereas the allowable tolerance for voltage is quite wide the frequency band is extremely narrow.

Many years ago I went with a party on a visit to the Drax power station. One thing that really interested me was the sight of two clocks on the control panel. One was clockwork and the other electric. The clockwork one showed the "true" time and the other was used to warn of frequency drop off in the wee small hours as it became slower than the other. Frequency then could be adjusted so they both agreed with each other. Simple but effective thought I.

The electric clock is a very old school, but quite accurate cumulative frequency meter.

 

I remember power line frequency counters from my university days. Back then they were built from tuned reeds (and no I am not kidding - pieces of wood otherwise used in things like musical instruments).  It was fascinating to see just how much the frequency wandered around in real time in sub-Hz meanderings*.  In these enlightened days I'm sure they are electronic.

 

* Of course the south-east Queensland grid wasn't the model of stability in those days.

[Ozexpatriate]

I take it we don't want to open up the subject of capacitive and inductive loads and power factor then.......

Indeed. We could discuss the implications of fluorescent (leading) and LED (lagging/reactive) power factors versus the humble purely resistive filament. Of course the controllers for LED lighting can be designed to look like a power factor of one to the supply.

[jjb1970]

The Bletchley Park Bombes depended on wire which depended on being tuned for want of a better word by a couple of local piano makers who worked entirely on listening to the wire to determine when it was right, no measurement or instruments. These days it is very easy to dismiss human capability and some of the old basic ideas and forget that a good operator can work to very high standards of accuracy using sense and some pretty basic technology. I found I couldgauge surface finish of machined components pretty much instantly just through feel and do it to sufficient accuracy to make some pretty important engineering decisions. The most critical task when building the propulsion system of a ship is the shaft line alignment (engine - gear box - shaft - stern tube - propeller)and despite modern laser tool a lot of guys in charge of the alignment prefer the old method using taut wire and do the job quickly and accurately with that technique.

[New Haven Neil]

Gearbox?  Not in my day, I don't know etc etc....(slow speed diesel ex-MN engineer officer!).

 

I recall frequency meters on one vessel that were made from vibrating reed like thin metal fingers, the correct frequency being the one that was wiggling up and down sufficiently for the end to appear blurred and therefore larger.

 

Oh, and we do charge for fraggle rock electricity exports......  

[raymw]

Neil - something like this?  http://www.richardsradios.co.uk/freqmeter.html