"cheap, reliable, and clean power...t a 170 megawatt natural gas generator"

Does this come under the heading of two out of three ain't bad? And that's assuming it satisfies "cheap".

Didn't EU declare that natural gas energy is green?

Greener than burning trees at Drax, at least...

Greener than burning trees at Drax, at least...

Especially when they are trees that have been shipped in from the US, in diesel-powered ships.

"Does this come under the heading of two out of three ain't bad? And that's assuming it satisfies "cheap"."

State energy is so amazingly cheap and reliable that MS built a gas generator to protect itself against the expensive and unreliable state energy. You would hope that was a wake up to the population

Energy in the UK has become more expensive and less reliable since privatisation as prices are jacked up to fill shareholders' wallets at the expense of maintaining infrastructure.

And Microsoft don't want to build the Dublin plant to "protect themselves" from EirGrid, it's the other way round. They want to build the plant because they're wanting to draw more power than the constrained regional grid can support. That grid isn't unreliable, it's just not designed for massive bloody datacentres in addition to its usual load. You wouldn't say your computer's PSU was unreliable if you slapped a massive GPU in the system, would you?

@Jedit

"Energy in the UK has become more expensive and less reliable since privatisation as prices are jacked up to fill shareholders' wallets at the expense of maintaining infrastructure."

Eh? Loadsamoney has been thrown at infrastructure. Look at the mass deployment of unreliable energy generation and problems involved.

"They want to build the plant because they're wanting to draw more power than the constrained regional grid can support."

Interesting they didnt put the datacentre where enough power was being produced. But then if the state isnt generating enough then build your own might be the only option.

"You wouldn't say your computer's PSU was unreliable if you slapped a massive GPU in the system, would you?"

No, I would replace the PSU to deliver what is needed. The opposite of our green leaders who want to reduce the power generated but expect to have cheap, reliable energy

Why DC for these high capacity lines? I thought the whole point of AC was there are fewer losses?

The tradeoffs are complex. In summary, if you absolutely do need a long cable - an AC system will suffer all manner of losses and performance problems with the loss of synchronisation of your three phases. This is because the cable is in effect, a giant capacitor. You can install equipment to correct for this, but it's more cost.

Jumping to DC for very long cables bypasses most of that particular set of risks; at cost of the conversion to/from AC/DC.

As a cable engineer of many years service then the top advice is don't build cables unless you absolutely have to. Overhead lines are the best solution if your criteria is minimum cost and maximum asset performance. NIMBYism is putting your bills up, because of the much more complex hardware required instead.

A/C, because as you may have guessed, am employed in the sector. I didn't have a hand in this particular decision but know enough to offer comment on it.

Thanks for the insights, not least reminding us (well me, at least) of the correct terminology -- if asked, I would have said overhead lines *are* cables. But you are clearly distinguishing between overhead lines and cables, and the difference is significant in this case!

Indeed. Even an overhead line is still a capacitor of a sort; with the air being the insulating medium instead of paper or plastics found on a buried or subsea cable. Wholly different magnitude of effect.

Another interesting option to consider would be higher voltages. In the UK we're limited by law to 400kV AC for onshore. This could be changed. There are diminishing returns because of humidity; though 550kV or thereabouts would offer a considerable performance uplift. While bigger, maybe not so many routes required?

Planning permission is what it is though. Most politicians are not keen to facilitate NIMBY triggers. Companies in the employ of actually having to get stuff done can't sit back and do nothing for the next 20 years waiting for political willpower to shift.

A serving of 1970's rolling blackouts would probably sharpen minds and willpower. I would rather it didn't come to that, but it might actually benefit us overall rather than kowtowing to the NIMBY brigade.

500kVAC and 765kVAC have been common transmission voltages in the US for decades, so it is a bit surprising to hear that 400kV is the legal limit in the UK. The +/-400kVDC Pacific Intertie was put into operation in the late 1960's, though was out of commission for a year or so after the 1971 Sylmar earthquake damaged the southern conversion station.

In the UK a lot of things are what they are because they have always been that way. The distances are somewhat shorter than Europe and the USA so maybe there just hasn't been a justification to upgrade. I know the UK has been re-wiring some of its 400kV network to reduce resistance and sag but the bits I've seen retained the same insulators.

The origins of our 400kV limit are similar to the origins of limitations that spring out of legislation around National Parks, etc. Basically, it was a concession made to get things moving. We'd have been stuck at 132kV if the NIMBY brigade had their way - despite that likely needing 20 to 30 times as many towers.

It probably could be raised if the case was made today, given the alternative is more 400kV routes or extremely expensive offshoring. Oh, wait...

For reference there is a megavolt+ route in India in development, however the humidity in it's intended location is extremely low. The very, very large towers needed for megavolt don't look all that big against backdrop of the Himalayas either.

Chuck in a compliant/oppressed populace and you don't have quite so many worries about whether you'll be allowed to build something.

The trouble is, our energy system as a whole is still AC, and relies on maintaining a steady 50Hz across the network. If the frequency drops below 47Hz or goes above 53, then many parts of it will suddenly trip offline in a cascade effect. Building DC internal links is troublesome, because it increases the grid capacity without strengthening the synchronous AC system.

If one of the DC links trips offline (as they are wont to do) then the AC transmission network suddenly has to pick up the slack and cascade failures resulting in loss of synchronisation ("grid islanding") or loss of frequency control, which can lead to a nationwide blackout of the sort that nobody is quite sure how long it would take to recover from.

The other big issue I have with HVDC subsea links is the vulnerability to enemy sabotage. [1]Spot the russian sub in this picture!

[1] https://ichef.bbci.co.uk/news/976/cpsprodpb/ff0c/live/cb14af60-58da-11ef-aebc-6de4d31bf5cd.jpg.webp

The grid tries to keep to +/- 0.5Hz with a long term zero deviation.

Do you remember the 2019 London blackout? Some of the overhead AC trains had a 49Hz lockout which required an engineer to reset them. The grid dropped to 48.8Hz causing chaos!

Yes, most DC/AC synchronous inverters have such a lockout because if the frequency is out of band then there is a risk they could end up in antiphase and blow themselves up.

In the [1]2019 blackout , one of the causes was that the brief dip in frequency caused a large windfarm to disconnect, (since modern windfarms tend to operate with DC/AC inverters rather than using synchronous generators, as it allows the turbines to spin at their most efficient speed. Solar farms also use inverters.) This led to the frequency dropping even faster, but luckily the ESO were able to load-shed in time to avoid any further cascade.

If there is a major frequency event that does cascade, we could lose all interconnectors, solar, and most of our wind capacity at a stroke. Then we'd be hurriedly reading the manuals of [2]project black-start to see if we can actually get the grid running again.

I've noticed a few times recently when the loss of a single 2GW interconnector from France has caused a fairly major frequency dip. e.g. [3]this one in January

If one big enough to cause cascade events happens, then we're in for something out of James Burke's [4]"The Trigger Effect"

[1] http://mainsfrequency.uk/fm-outage-aug-2019

[2] https://www.theblackoutreport.co.uk/2023/06/13/black-start/

[3] https://www.current-news.co.uk/ifa-interconnector-fault-causes-49-2hz-frequency-event/

[4] https://www.youtube.com/watch?v=NcOb3Dilzjc

The big problem was that after the trains locked out they were stuck in that state until you plugged a laptop in and cleared the faults. It is entirely legit for the system to shut itself down into a safe state in an out of range fault like that. But there should have been a way for the driver to reset it. Many trains could be reset but the lines were blocked by the ones that couldn't be. The impact of that blackout would have been somewhat smaller had the trains got moving again sooner.

Domestic solar generation will also trip out for the same reasons. Inverter tolerances have improved over the years though the older ones are pretty intolerant. Domestic generation is of course not metered centrally, but in that 2019 blackout there was estimated to be something like an additional 200-300MW dropped until the system frequency could be restored by load shedding - at which point the inverters kick back in again and risk chucking the frequency up too high if over-compensating.

Large batteries, preferably distributed around the system, with uber quick response times would be a useful addition to the toolbox to manage such risks. Dinorwig pumped storage can be fast, but still a few seconds from the point someone actually pushes GO.

Synchronous compensation (e.g. a flywheel) is also viable, though someone then has to pay for that flywheel to spin. Historically, the flywheel WAS the generator attached to the coal plant or nuke. Most of those long gone - and I'll leave it to the reader whether they think that was a better solution or not because it is a guaranteed argument trigger.

In the meantime ESO have raised reserve generation holdings to provide a better hedge against failures like the 2019 events.

One question I can never find an answer to from experts on the subject is: Why is the UK grid frequency so unstable compared to other countries? In Europe it rarely deviates +/- 0.02Hz for example.

A cynic might say that it could have something to do with the market structure whereby generator operators are paid exorbitant amounts to take emergency actions to stabilise the grid frequency, so those same operators have a vested interest in letting it slip in the first place.. This was reported on in the Private Eye a while back.

How much of Europe is frequency synchronised? Gridwatch doesn't show the French grid freq.

The implication from this map is that there is a lot of AC interconnection

https://www.entsoe.eu/data/map/

Which would make the grid inertia absolutely HUGE.

It's enormous, it extends from Portugal to the Baltics. Even Ukraine was connected up to it after the war kicked off - though I am not sure of current status. The situation there is obviously very fluid.

Big networks with lots of spinning plant do not offer immunity from problems, despite the perception of "big spinny flywheel inertia be good". Realities are not so simple. There was a fault a few years ago where an overstacked barge shorted a line out on a canal in Germany. Assets were tripping as far away as Portugal as a result.

Like with information networks, interconnection is both a boon and a curse.

The scale is probably why they have to keep the frequency stable :)

The bigger things are the harder they fall. You can understand why the US is not frequency sync'd. Although I will never understand Japan... 50? 60? Sod it, both!

Yes the grid is AC and will remain that way for the forseeable future.

HVDC only became practical & cost-effect several decades ago and has some significant advantages in terms of cable losses and peak insulation requirement, but one very important aspect for the UK-France interconnect was it avoided the need for both sides to be synchronous. The down-side of this if, of course, that such AC/DC/AC inverters lack any "inertia" and can lead to a grid cascade failure when something trips off and overloaded turbines spin down, this is very apparent with renewables as mostly they are inverter-connected as either DC in the first place (PV panels) or are running asynchronously to the grid (variable speed wind turbines). There are requirements being added for large projects to have "synthetic inertia" where the inverter attempts to maintain a constant AC frequency and will run with reactive currents in order to do so (to a certain limit). This would reduce the risk of a small outage triggering such a cascade fault.

Why will AC remain? Well it is cheaper to have a transformer in general (cost and longevity), it is far easier to break an AC fault (as the current goes through zero-crossing the arc tends to extinguish more easily), and most of the world is based on it so the investment to change is absolutely massive (i.e. you are rarely starting new, unlike say a DC bus data centre arrangement, etc).

"Overhead lines are the best solution if your criteria is minimum cost and maximum asset performance. NIMBYism is putting your bills up,"

And unfortunately public opinion is conditioned by those hideous monstrosities National Grid have used for pylons since the days before time.

Our AC will know anyway, but wider public opinion is less informed that more recent designs are far less intrusive, such as the T pylons being used to connect Hinkley Point C. If anyone's used the M5 recently between Weston and Bridgewater these are visible from the motorway. Whether all new pylons are to good designs I don't know - sceptics might think a dinosaur like NG will probably only be using T pylons for a bit of publicity, and everywhere else it's the same old rubbish design.

And as a personal view, the T pylon wasn't as good as Arup's A pylon that was also offered into the National Grid competition.

The problem with the T pylons, is that because the national grid didn’t commit beyond the initial trial, the UK company went bust and the pylons for the current “M5” deployment were sourced from China, prior to the current US driven sanctions policy…

There were several aesthetically pleasing designs: https://www.theguardian.com/environment/gallery/2011/sep/14/shortlist-designs-electricity-pylons-in-pictures

I don’t remember if any actually used less materials than the 1950’s designed NG pylon.

My concern over some of the composite material designs is the longevity, these really are structures that need a design life of 100+ years…

Ah, another case where we're making something out of steel and have to buy it from overseas due to no UK steel industry being left?

In Norfolk there are 10m wide swathes being dug up to put in hvdc cables from off-shore windfarms as it wasn't possible to route them anywhere else ... like putting in an undersea interconnect to Sizewell for instance ... and the closest place with national grid capacity for one of them was south of Norwich. Much fighting but "they" got their way. Now "they" are building pylon interconnects to London as the place they are connecting to (with the required capacity as specified in the planning application) doesn't have the required capacity ... The Dutch interconnect windfarms offshore then bring the whole lot onshore from a central point - much cheaper and efficient but apparently we can't do that because there are too many greasy palms involved.

I've also seen reports that wind noise with the T-pylons is much higher than from traditional lattice pylons, and is upsetting people who live near where they've been installed.

> There were several aesthetically pleasing designs: https://www.theguardian.com/environment/gallery/2011/sep/14/shortlist-designs-electricity-pylons-in-pictures

Hell's teeth, there's some real fugly nonsense there! I actually quite like the British Standard Pylon, a majestic steel giant holding wires aloft. A small price to pay for the benefits of mains electricity, that we all depend on for every aspect of our lives.

> I actually quite like the British Standard Pylon, a majestic steel giant holding wires aloft. A small price to pay for the benefits of mains electricity, that we all depend on for every aspect of our lives.

Indeed! And a whole website dedicated to their practical magnificence: https://www.pylonofthemonth.org/

Nothing wrong with good old 400kV air-insulated AC transmission lines - but thanks to NIMBYs we are going to spend a whole lot more money to get something much less resilient.

Same A/C again.

T-pylons are hideous from an asset ownership point of view. Do you keep the castings around in perpetuity for when you (eventually) need a spare to replace the original? Do you stamp out a few spares and store them for 40 years?

Classic lattice towers you can buy a bit of appropriate grade steel from "anywhere" with no such issues. Catch the T-pylons from the wrong angle and they look like a wall.

In a public consultation for another route; a lot of the feedback was "build whatever you need, but DONT use T-pylon!"

Public opinion is what it is, fickle. Not what you need when you are talking about one of the major pillars of the economy running!

This was the whole point of the lattice pylons coupled with the relative ease of assembly as you could make them in small sections and didn't need huge cranes.

https://www.youtube.com/watch?v=uUowNWSk4uU

A total H&S nightmare but that hadn't been invented yet ;)

A long buried or submerged cable has a significant capacitance to ground, which in an AC system has to be charged and discharged 100 times a second. That current creates extra I^2R losses.

Underwater cables running AC are limited by the capacitance between the different phase conductors (and to an extent seawater). In ordinary situations that's not too big a deal, for long distance cables this means an AC cable loses power to reactive losses, and the longer the cable the greater the losses. If the cable is long enough then all the power that goes in is lost to reactive power losses, and you get no usable power out at the end - on an unmanaged 220kV cable that can be as little as 120km. There are technologies to manage reactive power losses, they cost money so it's a calculation to work out what is the optimal approach, DC or AC, and at about 70-100 miles it usually favours DC.

If you're linking different grids that aren't in phase (eg UK to Europe), it's also somewhat easier to manage a DC connection, although that doesn't apply in this case.

"Access to cheap, reliable, and clean power remains one of the datacenter operators top concerns"

Really? Cheap and reliable yes but clean seems to have been bolted on there. Worse is the question of who's idea of green? Drax burning imported wood? Inefficient running of gas generators to support unreliables? Clean as in less plant food?

It seems our obsession with the weather cult is driving us away from cheap, reliable and clean energy

NetZeroWatch called. They want their post back.

If cheap is the criteria then we should be building overhead line.

See above for why.

Also it's less easy for a Russian trawler to 'accidentally' cut a cable if it's 20 miles inland and 100 feet up in the air.

I would not put it past them!!

People have developed an aversion to pylons dotting the landscape. One planned route from the highlands has been scuppered due to the locals saying no to the pylons.

People have developed an aversion to pylons dotting the landscape. One planned route from the highlands has been scuppered due to the locals saying no to the pylons.

Somewhat ironic. Is the problem that the pylons might obstruct views of the windmills?

But at least if this cable goes ahead, England will be able to export organic, wood fired electricity to Scotland when the wind doesn't blow. Unless England needs it, because the wind probably won't be blowing here either.

Its organic North and South American wood fired electricity! Transported using diesel engines....

I'm waiting for 'Beyond wood' and 'I can't believe its not wood' :)

Left and right hands?….

“ a £3.4 billion project to construct an "electricity superhighway" between Scotland and Yorkshire.”

[1]” The UK's £1.3 billion ($1.66 billion) plan for AI and tech investment that included an £800 million ($1 billion) exascale supercomputer at Edinburgh University has gone up in smoke.”

Or can we expect an announcement that one of Manchester / Sheffield / Leeds is the new location of the UKs exascale computer…

[1] https://www.theregister.com/2024/08/05/axe_exascale_uk_edinburgh/

"Or can we expect an announcement that one of Manchester / Sheffield / Leeds is the new location of the UKs exascale computer…"

More likely Imperial, UCL, King's College, or out in the wilds of Oxbridge.

Don't want it too far from London

(message sent from the University of Aberdeen, beyond the "here be dragons" bit on the map)

Well Starmer did get an honorary degree from Leeds, so at least he will have heard of it.

But then the University of London is in his constituency…

That'll definitely reduce our 'leccy bills.

2029 would be in line with the ban on new ICE's that had been put back to 2035, but labour might bring forwards again to 2030.

Add in the push for air source heat pumps, which seem to be more like electric central heating (as some who have them have reported), plus replacing gas appliances with electric as we'll be an all-electric nation! AND the increase in demand from the expanding data centres and AI sites...

what could possibly go wrong?

(over spend, delays, and the result not being to requirements at a guess).

> which seem to be more like electric central heating

And not particularly energy efficient electric heating. The intention is for the system to be a “drop in replacement” to the gas boiler.

This new cable will only provide 1kW to each of those "2 million homes", so let us hope that they don't want to use their heat pumps, or charge their EVs, or even have an electric shower (even individually, never mind at the same time!).

Oh, and that is assuming that the wind is blowing in the first place!