Green Building Forum - Is Hinkley C dead? Mon, 07 Sep 2026 13:45:51 +0100 https://www.greenbuildingforum.co.uk/newforum/ Lussumo Vanilla 1.0.3 Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245251#Comment_245251 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245251#Comment_245251 Sat, 06 Aug 2016 07:22:55 +0100 SteamyTea
It may well be possible to design a system with a DC backbone and no rotating machinery, but I think that the physical properties start to change i.e. voltage lagging current, switching.
I also think that the main problems would be the cost and thermal losses once you start to add in thousands, or millions even, of PSUs.
I would have to get my old electrical engineering books out to refresh myself on what is going on.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245254#Comment_245254 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245254#Comment_245254 Sat, 06 Aug 2016 08:12:02 +0100 finnian
Voltage lagging/leading current is a question of what the load is: whether it is capacitive or inductive. You can power either with an inverter. Not sure why there would be any more losses over and beyond the ones that are already involved in PV generation with inverters.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245256#Comment_245256 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245256#Comment_245256 Sat, 06 Aug 2016 11:06:55 +0100 barney
A grid needs to be able to deliver volt amperes and receive volt amperes reactive

A 100% asynchronous grid cannot do that - it is grossly unstable

My point initially was we cannot swap out HPC for £18 billion PV - we could swap it for the barrage

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245258#Comment_245258 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245258#Comment_245258 Sat, 06 Aug 2016 13:32:44 +0100 fostertom Posted By: SteamyTeathermal losses once you start to add in thousands, or millions even, of PSUs.Losses matters less if the marginal cost of energy (cost of units of energy captured beyond the capex fixed finance cost of PVs, turbines etc) is nearly free. Different from fuelled generation, where the marginal cost (£ and CO2) of generation is considerable per unit generated.

Posted By: finnianhydro ... are rotating machinery: so are wind turbines
but at uncontrollable frequency, so that doesn't help.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245259#Comment_245259 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245259#Comment_245259 Sat, 06 Aug 2016 14:32:09 +0100 barney
Once you lock in to the grid all you need to do is increase flow rate to produce more power

It's very stable as it's big rotational plant

Exactly the opposite of invertor based PV and some wind

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245261#Comment_245261 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245261#Comment_245261 Sat, 06 Aug 2016 17:44:48 +0100 fostertom Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245264#Comment_245264 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245264#Comment_245264 Sat, 06 Aug 2016 18:00:12 +0100 Gotanewlife Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245266#Comment_245266 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245266#Comment_245266 Sat, 06 Aug 2016 18:38:22 +0100 fostertom Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245267#Comment_245267 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245267#Comment_245267 Sat, 06 Aug 2016 19:21:55 +0100 barney
Same as you vary steam flow rate into a steam turbine

Physically it could be a number of devices such as wicket gates and pin nozzles

Generally once the alternator is locked in via the automatic voltage regulator then you just allow more water in to increase power output

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245268#Comment_245268 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245268#Comment_245268 Sat, 06 Aug 2016 19:43:54 +0100 fostertom Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245271#Comment_245271 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245271#Comment_245271 Sat, 06 Aug 2016 21:10:27 +0100 barney
Obviously once you are below the minimum design head you have to reduce power - and you might want to run just below peak output as a bit of reserve for load fluctuations or maintenance of grid frequency

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245274#Comment_245274 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245274#Comment_245274 Sat, 06 Aug 2016 22:11:22 +0100 finnian
Certainly rotating machinery is the traditional way to run grids, and stability is conceptually explained to students in terms of these rotating machines, but that doesn't mean it is the only way to do it! An inverter is quite capable of reacting the same way as a synchronous motor or generator to load variations.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245277#Comment_245277 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245277#Comment_245277 Sat, 06 Aug 2016 23:19:06 +0100 barney
Invertors track voltage and frequency (and have to disconnect within strict limits) - an excursion outside those limits can suddenly disconnect all the iinvertors - which can generally only be rectified by big synchronous generation - or the grid collapses

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245282#Comment_245282 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245282#Comment_245282 Sun, 07 Aug 2016 09:02:39 +0100 fostertom Posted By: barneyProvided it has a stable grid to synchronise withI haven't heard it explained yet why it has to be a 'stable grid' i.e. totally dominated by actual rotating generators - rather than a rock-stable, same-everywhere 'heartbeat' electronic signal - which obviously can't be 'bent' while modifying any new asynchronous input.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245284#Comment_245284 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245284#Comment_245284 Sun, 07 Aug 2016 09:22:19 +0100 billt
There's no reason in principle why you couldn't use some sort of electronic signal as a reference but it would involve throwing the current infra-structure away and building a new one. Of course that would be fantastically expensive and wasteful of resources, so it isn't going to happen.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245285#Comment_245285 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245285#Comment_245285 Sun, 07 Aug 2016 09:28:41 +0100 Mike1 Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245288#Comment_245288 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245288#Comment_245288 Sun, 07 Aug 2016 10:51:08 +0100 fostertom Posted By: billtuse some sort of electronic signal as a reference but it would involve throwing the current infra-structure awayWhy? the electronic signal would be synchronised with the rotationally-sync'd grid, for as long as rotators continued in use. Either method could be used at any time, would produce same result.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245290#Comment_245290 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245290#Comment_245290 Sun, 07 Aug 2016 11:53:22 +0100 barney
Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245302#Comment_245302 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245302#Comment_245302 Sun, 07 Aug 2016 19:26:05 +0100 ringi
Also the fault current is very large on a large grid and a lot smaller on local “grid”. Say each town has a large fault once a year, we would be happy with the town losing power for a minute or two, but we are not happy with the country losing power every time there is a fault on the 11KV system. So a national wide grid is a lot harder to get “stable enough” then a small local grid. Hence once the cost of HVDC links come down, we may see NEW "grids" being designed so that each town is independent of each other with CONTROLLED flow of power between them.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245306#Comment_245306 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245306#Comment_245306 Sun, 07 Aug 2016 20:20:09 +0100 Ed Davies Posted By: ringiSomething that is being missed, it cost little (or nothing) more for a rotating steam or hydro power station to be built so it can help regulate the frequency of this grid. However an inverter will need lots of quick response storage (super caps for example) along with a lot more expensive power electronics and safety systems. So far wind farms have not been willing to install such invertors.I'd think there's a fair amount of rotational energy stored in wind turbine blades. I don't know how the inverters in a typical large wind turbine are set up but it wouldn't surprise me if they didn't already contribute to grid stability or could be made to do so with a small matter of programming.

There's a lot to be said for electronically synchronizing the grid. The other year there was a 36 hour power cut here in Caithness because lines up from Perth to Inverness went down (combination of wind and snow, I think). Shame to be sitting in the dark with a county full of wind turbines stopped when electronic synchronization could have kept a local grid running and in sync ready to reconnect.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245310#Comment_245310 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245310#Comment_245310 Sun, 07 Aug 2016 21:08:09 +0100 barney
Back to that big stable grid - we do have one at the moment. To get those turbines tuning together in island mode from the load end of a system will need a different infrastructure approach

It must have needed some speedy intervention further south to rapidly make good the sudden loss of those turbines

Regards

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245316#Comment_245316 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245316#Comment_245316 Mon, 08 Aug 2016 00:11:48 +0100 finnian
They have nothing to to with the capabilities of inverters and also apply to micro-hydro and household-scale wind as well as PV.

Distributed generation is forbidden to output to the grid if the grid goes into a fault condition. This is a matter of regulation rather than capability.

The biggest stresses on the grid arise due to trips of large single generators (i.e. coal or nuclear), or a link going down. Suddenly you need to find an extra GW.

Country-scale grids have operated almost entirely on a mix of PV and wind for hours at a time without the world ending, so I think that the difficulty of this is being somewhat exaggerated.

The problem of storage/intermittency is really much harder than stability, and having large scale storage would immediately allow you to solve the stability problem.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245322#Comment_245322 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245322#Comment_245322 Mon, 08 Aug 2016 08:30:58 +0100 barney
Why do you think small scale embedded generation needs to turn off

It's only the wind and solar need storage - fuelled plant already has plenty of storage

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245323#Comment_245323 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245323#Comment_245323 Mon, 08 Aug 2016 08:49:34 +0100 fostertom http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14310&page=5#Item_6 - for example
http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14413&page=3#Item_5]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245324#Comment_245324 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245324#Comment_245324 Mon, 08 Aug 2016 08:52:23 +0100 Ed Davies Posted By: barneyWhy do you think small scale embedded generation needs to turn off
Two reasons:

1) So as to allow people to work on the damaged local distribution network safely once it's been isolated at what's traditionally its only supply point(s).

2) So that when it is reconnected the two systems aren't dramatically out of phase.

If local generation was a normal expectation of distribution network engineers and phase information was transmitted electronically then there's no reason why islanding couldn't be done safely. It'd help resilience a lot.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245332#Comment_245332 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245332#Comment_245332 Mon, 08 Aug 2016 09:39:57 +0100 barney
I guess then Ed, you've just made the case for having a big stable grid

Basically, what we have is a grid system designed for large scale generation, transmission, distribution and consumption - it handles voltage control and frequency stability very well, it is responsive to short term load fluctuations, medium term load shifts, fault clearing capability and a mix of generation types

Now we want a grid that massively distributes generation, removes a significant amount of inertia in that generation, expects systems designed for distribution to now act as transmission and expects transmission systems to be able to move power through when generation and load are significantly displaced

It's why the massive wind generation in north Germany is a major problem for the grid operators that requires rerouting through Poland and Austria to south Germany where the load is - that's the underlying reality

I'd be perfectly happy with a redesigned, fit for purpose new grid system (shall we say circa Euro 500 billion) - what we can't do is keep increasing the penetration of wind and solar without maintaining enough high inertia plants to maintain stability and providing in country bypass (HVDC) to allow transfer
Regards

Barney]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245334#Comment_245334 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245334#Comment_245334 Mon, 08 Aug 2016 10:14:20 +0100 Ed Davies
Why would we say that? It sounds implausibly large. Generation costs of the order of £1/W (bit less for gas, bit more for nuclear, more still for wind, etc). We need about 60GW of generation so perhaps €100 billion. I don't think the grid will cost more than the generation: National Grid's market capitalization is around £40 billion [¹]. The market cap isn't a terribly good guide to the replacement cost of the assets but must give an order of magnitude idea.

So, replacing the entire electricity infrastructure might cost of the order of £200 billion. That's about 4 years of the defence budget (or about 8 years of the saving if we spent about the same per capita as most large European countries) which is largely spent with the aim of obtaining energy sources, anyway.

Any realistic phased (haha) modernization would cost a lot less. You don't need to knock pylons down if you replace stability from rotational inertia with electronic control.

[¹] http://shares.telegraph.co.uk/quote/?epic=NG.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245335#Comment_245335 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245335#Comment_245335 Mon, 08 Aug 2016 10:18:33 +0100 Ed Davies Posted By: barneyI guess then Ed, you've just made the case for having a big stable gridNobody's disputing that that's a good thing. The question is whether it necessarily requires large amounts of rotating machinery to obtain that stability.]]> Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245340#Comment_245340 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245340#Comment_245340 Mon, 08 Aug 2016 10:52:22 +0100 finnian Is Hinkley C dead? https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245343#Comment_245343 https://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=14100&Focus=245343#Comment_245343 Mon, 08 Aug 2016 10:55:59 +0100 barney
I did add a rough order figure however for storage systems which we are likely to need

In terms of rotational plant - I guess we will always have a differing viewpoint - from all sorts of studies I've seen over a number of years, stability tends to diminish as you add more invertor based technology and less rotational units - basically the torque aspect required for ride through, the variability of the power source (input power) and the inability to operate other than inside quite tight tolerances with each other or with a grid

If we accept that invertor based systems are deployed on the ends of distribution systems and are not in the control of grid operators, then they will always need a stable power source to allow synchronization.

If we group them together in "farms" or "plants" (a bit like traditional generation) that's a different issue - but that's not where we are going at the moment with Tom's "autonomous grid" (I've read that as we all have a bit of generation and we make that available to a wider grid)

Given the variable and uncontrolled input I don't see how we can avoid "traditional" rotating plant (but we can spin that plant from greener fuels which could be wind or solar via gasification or into motor generators, water storage etc)

It might be worth repeating the question - can the UK meet it's energy needs from autonomous, wind and solar with an entirely invertor based grid even if that needs HV DC interconnection from Europe (regardless of the generation source) for when it's dark and still

Would we need to impose rotational plant for stability (driven from storage) ?

Regards

Barney]]>