UK Electricity Interconnectors – a Double-Edged Sword

The UK currently has four interconnectors totaling 4 GW of capacity:

  1.  2 GW with France (the IFA link)
  2.  1 GW with the Netherlands (the BritNed link)
  3.  500 MW with Northern Ireland (the Moyle link)
  4.  500 MW with the Republic of Ireland (the East-West link).

Section through a submarine cable (credit Subsea Cables UK)

Overall these interconnectors have contributed significantly to UK electricity supply over the last few years. In the third quarter of 2013 they in fact delivered almost as much electricity to the grid as wind and solar (6,031GWh vs. 6,680GWh).

The UK’s energy plan assumes that more interconnectors will contribute to future energy security by allowing power surpluses on the Continent to be delivered to UK when power is in short supply. And the more interconnectors the better, hence additional interconnectors with France and Ireland plus new interconnectors linking the UK with Belgium, Denmark, Norway and Iceland are now in various stages of planning or construction. If all of them are completed on schedule the UK will have somewhere around 12GW of interconnector capacity – three times the current amount – by 2020.

But will these interconnectors increase UK energy security? Here we will look at what the four existing interconnectors have done so far.

Figure 1 shows the growth of net UK electricity imports since June 2011 (data from Gridwatch). The data are plotted as weekly averages to make them more readable and the month scale is approximate:

Figure 1: Net UK interconnector flows (weekly averages) since June 2011

According to the trend line the UK’s electricity imports have increased by almost a factor of four since June 2011, although there have been periods during which the UK became a net exporter. We will get to them shortly, but first we will look at imports and exports by country. Here’s France:

Figure 2: Net UK interconnector flows (weekly averages) with France

Imports from France are erratic and in February 2012 turned strongly negative (i.e. the UK was exporting power to France). Overall, however, they are dominantly positive, and during 2014 they have often been running at or close to the full 2GW capacity of the IFA interconnector. (The fluctuations are presumably a result of the “congestion revenues” pricing mechanism which according to Ofgem makes flows “dependent on the existence of price differentials between markets at either end of the interconnector”. We can therefore assume that electricity flows dominantly to UK from France because French electricity is usually cheaper than UK electricity, all other things being equal.)

Figure 3 shows the Netherlands’ contribution. Imports from the Netherlands are more stable than those from France but also turned negative on two occasions in 2011. The BritNed interconnector has also been running at or close to its full 1GW capacity for most of the time since the beginning of 2014.

Figure 3: Net UK interconnector flows (weekly averages) with the Netherlands

Figure 4 shows the sum of the two Irish interconnectors – Moyle to Northern Ireland and East-West to the Republic of Ireland (Ireland and Northern Ireland are linked by the Irish grid). The UK consistently exports electricity to Ireland, although the two interconnectors commonly operate at less than their combined 1GW capacity:

Figure 4: Net UK interconnector flows (weekly averages) with Ireland

We will shortly examine three of the periods since June 2011 when the UK became a net exporter of electricity, but to provide a point of reference we will look first at what happens when the grids are unstressed. Figure 5 plots interconnector flows against UK electricity demand for July 2014. Imports from France and the Netherlands are at full interconnector capacity except for sporadic decreases during minimum UK demand periods. Flows to Ireland are dominantly in the opposite sense, with exports from UK reaching their maximum during peak UK demand (which presumably coincides within an hour or so with peak demand in Ireland) and only minor imports to UK during off-peak periods. Interconnectors made a net positive contribution to UK energy supply in July 2014, but energy supply in low-demand summer months is of course not usually a concern.

Figure 5: UK Demand and interconnector flows, July 2014

Now to the periods when the UK exported electricity. First November/December 2011 (there were no flows to and from Ireland over this period):

Figure 6: UK Demand and interconnector flows, November/December 2011

Electricity flows over the period were inversely correlated with UK demand, with power imported from France and the Netherlands during lower-demand weekends but exported to France and the Netherlands on higher-demand weekdays. Weekend imports were effectively random relative to demand but weekday exports were highest (up to 3,000MW) during peak UK demand hours. Clearly the interconnectors were compromising UK energy supply, not reinforcing it, during this three-week period.

I’ve not been able to discover exactly what triggered the exports of electricity from UK to France and the Netherlands in November 2011 (weather does not seem to have contributed) but the underlying cause was Germany’s post-Fukushima nuclear plant shutdown, which cut French power imports from Germany to the point where France had to import power from elsewhere. Computescotland predicted it:

With the recent German nuclear closure, losing it approximately 8GW may have a knock-on effect to the UK electricity market, impacting imports and exports and possibly at peak demand, as Germany, once a net electricity exporter becomes a net importer.

Second, January/February 2012:

Figure 7: UK Demand and interconnector flows, January/February 2012

This period coincides with a cold spell that stressed electricity supply all over Europe and led to a reversal of flow along the IFA interconnector with France that lasted with a few brief interruptions for over three weeks. Flow was also reversed along the BritNed interconnector during periods of weekday peak demand, mirroring what happened in November/December 2011. When Ireland is included the UK was often exporting over 3GW during peak winter demand periods. Clearly the interconnectors were compromising UK energy supply during this period too.

And the culprit? According to Reuters, Germany again:

France will for the first time import more electricity from Britain than from its long-standing partner Germany at peak time on Monday as the Germans are forced to retain spare generation during icy weather, the French energy minister said on Monday. “For the first time, the United Kingdom and not Germany is the main country which provides us with electricity imports,” Energy Minister Eric Besson told reporters at the French electricity network control centre. Germany shut down eight of its oldest nuclear reactors last year in the aftermath of Japan’s nuclear crisis and the current cold weather is putting Germany’s tighter supply balance to the test for the first time since then.

Third, November/December 2013

Figure 8: UK Demand and interconnector flows, November/December 2013

Interconnector flows over this period mirror the January/February 2012 flows but at generally lower amplitude and for a shorter time. Again I am unable to discover exactly what the trigger was but the similarity to 2012 suggests that real or perceived shortages in Germany were once more the underlying cause, although the extreme storminess over this period may also have contributed. (December 2013, coincidentally, was the month DECC published a report entitled “More interconnection: improving energy security and lowering bills”, in which it admitted in the fine print that “The evidence also indicates that interconnection projects can have very different and uncertain impacts, some negative, depending on: the markets involved; the connection point into the transmission system; timing; and how European energy systems evolve.”)

What do the above results tell us? Basically that the UK’s interconnectors can be relied on to deliver electricity in the summer and during low-demand periods in the winter when the UK doesn’t need it but not during winter peak demand periods when it does – in fact they usually take it away instead. A double-edged sword indeed.

AFTERTHOUGHT: Fawley to the rescue.

One would like to think that the “congestion revenues” mechanism that governs interconnector flows is self-regulating to the extent that it doesn’t require the UK to keep exporting electricity when the reserve margin falls to critically low levels. But unless the rules have changed in the last couple of years it seems that it does. According to an article in the Express the National Grid came within an ace of having to black out a million homes on January 16, 2013:

Alistair Buchanan, the outgoing head of energy regulator Ofgem said: “On Wednesday, January 16 (2013), due to unplanned outages and cold weather, National Grid had to find power to supply roughly a million homes to keep the lights on. Fawley, an oil-fired plant in Hampshire, was one of the power stations that responded. Next year Fawley will not be there.”

The near-blackout, however, was only partly due to unplanned outages and cold weather. Exports made a major contribution. Figure 9 tells the story:

Figure 9: UK electricity demand and net imports/exports, January 16, 2013

Output from Fawley peaked at 970 MW at around 1600 hours. At this time 228 MW was being imported from France, 256MW was being exported to the Netherlands and 500 MW was being exported to Ireland. One could be excused for thinking that the UK’s interconnectors are there to keep the lights on in Ireland.

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67 Responses to UK Electricity Interconnectors – a Double-Edged Sword

  1. edhoskins says:

    In bald terms, as and when France needs its own supply, does anyone seriously think that they will not favour their own customers over those in countries overseas like the UK whatever the contractual arrangements may be. The light will go out in the UK before they do in France.

    The interconnectors are a a stop gap but they will only work in the good times. In emergency they can only increase the risk to the UK and Irish grids.

  2. Joe Public says:

    A valuable insight into yet another aspect of our energy situation. Thanks Roger.

    • Mike Parr says:

      I disagree, it omits completely the fact that, for example, the Brit-Ned connection is 100% merchant – flows are driven only by trading between NL and UK. Having visited the location & the control room – this is clear – at a glance. The article fails to address the “market only” approach which continues to be seen as the best way forward for UK energy. This is the mantra in the UK & has been since 1990.

      What Mr Andrews does is chart the problems – & offers no solutions.

      • it omits completely the fact that, for example, the Brit-Ned connection is 100% merchant – flows are driven only by trading between NL and UK.

        Okay, let’s add it in. What difference does it make?

        The article fails to address the “market only” approach which continues to be seen as the best way forward for UK energy.

        I noted several times in the post that interconnector flows are governed by the market-based “congestion revenues” mechanism. To support your statement you also need to supply evidence that this approach is contributing to UK energy security rather than undermining it. Do you have any?

        What Mr Andrews does is chart the problems – & offers no solutions.

        Offering solutions wasn’t part of the post, but now that you mention it the solution is obvious. Quit installing intermittent renewable capacity and start installing dispatchable capacity.

        Your last two sentences were not constructive and were deleted in accordance with blog policy.

  3. Nick Perrin says:

    A revealing analysis – thanks. I hope to see more comment on this vital issue for the UK. Maybe we can draw more conclusions from the use of the interconnectors within the EU.
    Could you put ‘NET’ on the Fig 1.
    Please will you post regular analysis of the grid data.

    Ed’ :-
    I read the future extension of interconnectors as indicating a growing EU power interconnected Grid rather than ‘a stop gap’. I consider it will be the way they are used that will improve our power security or put it more at risk. Overall I see the interconnectors as ‘sharing’ the risks (and power) in Europe as more reliance is put on renewables.


  4. Euan Mearns says:

    Roger, interesting data. I guess the big surprise for me is to see that we are simply using the interconnectors to import electricity. I imagine it is cheaper and easier than importing gas and making it ourselves. When the wind blows hard and we are curtailing generation and paying operators to do so, why are we not exporting instead? This after all is what we are told interconnection is for.

    I’m also surprised to see that little effort seems to be made to use interconnection to load balance the grid when it comes to imports, especially the last 12 months. Exports to Ireland seem to be more variable.

    A bit bizarre that during the December 2013 event we were exporting 2 GW to France while importing 1 GW from Netherlands.

    Do you know how electricity imports affects UK CO2 budget?

    • Euan: You really need an expert to comment on the inner workings of the congestion revenues mechanism, but the basic idea seems to be to move power from places where it’s cheap to places where it isn’t (It requires all interconnection capacity to be allocated to the market via market based methods, ie auctions, says Ofgem) which isn’t necessarily the same thing as moving power from places where it’s abundant to places where it’s scarce.

      But I’m not sure this applies to Ireland. As the graphs show the UK consistently exports power to Ireland during peak periods, winter or summer, rain or shine, sleet or snow, implying that electricity in Ireland is always more expensive than in UK, but only during peak periods. Exports to Ireland are only in the hundreds of MW range, which in normal times wouldn’t be all that much, but with UK reserve margins hovering around 4% they become significant.

      When the wind blows hard and we are curtailing generation and paying operators to do so, why are we not exporting instead? This after all is what we are told interconnection is for. Good question, I don’t have a ready answer. Complicating the issue is the fact that the EW interconnector is supposed to be delivering surplus Irish wind power to UK, not delivering UK power to Ireland.

      There isn’t enough imported power to make much difference to the UK CO2 budget. Figuring out where it came from would be difficult anyway. The nuclear power imported from France, for example, might have been displaced by German lignite, which might have been displaced by Norwegian hydro that originated as Danish wind power. All very complicated. 🙁

  5. Paul says:

    interconnectors can be relied on to deliver electricity in the summer and during low-demand periods in the winter when the UK doesn’t need it but not during winter peak demand periods when it does – in fact they usually take it away instead

    To reach this conclusion when your first graph show almost continual imports, you must have a new definition of “usually”. And to assume that, has Fawley not existed, the grid would have cut off supply to UK homes before cutting off the interconnectors is unjustified.

    To say that interconnectors were compromising UK energy supply, as you do more than once, with almost continual 2GW imports and without evidence that UK supply was ever endangered by exports is strange.

  6. Sam Taylor says:


    Could you explain the difference between a “near-blackout” and a “non-blackout”?

    • And your point is?

      • Paul says:

        Same as mine perhaps – there was no blackout. NG chose to maintain exports and national demand by bringing online an oil-powered plant. It could have chosen to restrict exports but the availability of Fawley meant it didn’t have to. You are suggesting that this wasn’t a rational decision based upon the normal parameters of grid/interconnector operation but instead that it was a “near blackout”. Yet you present no evidence to support that claim or any other claim about interconnectors “compromising UK energy supply”.

        Conventional and nuclear plant trip offline quite often and the grid is built in such a way that losing 1400MW doesn’t cause and actual blackout, but in many cases I imagine we could say there was a “near blackout” without invoking foreign connections.

        The obvious conclusion from your charts is that they provide a lot of cheaper power to us and to Ireland. For some reason you want to turn that into a failure or risk.

        • Yet you present no evidence to support that claim or any other claim about interconnectors “compromising UK energy supply”.

          Paul, either you are incapable of understanding graphs or you are deliberately trying to get me to waste my time responding to your bizarre comments, and I can assure you I have better things to do.

          That being the case I give you two options. Either present graphs or other hard data to show where I am mistaken – the data you will need are all available on Gridwatch, which is linked to in the “Energy Data” box – or be placed on the moderation list.

          • Paul says:

            Roger, I think I understand the graphs well and I have no intention to waste your time. Just ignore what I write if it is so bizarre.

            However, to show that exports undermined our energy security, you’d need to show that:

            1. there was insufficient UK generation capacity to support both domestic and foreign demand. In 2012, your first example of strained supply, the available generating margin was 17%. So 17% over maximum normal demand (whether that maximum includes export demand I don’t know). It was around 6% in 13/14 which might be more cause for alarm, but your graphs show total demand well below 55MW.

            2. and that in the event of a shortfall, foreign demand would be given priority over domestic. You imply it is a ‘bizarre’ opinion, but I can’t imagine the operators of either the UK or French grids initiating a local blackout in order to supply foreign demand.

            If I were to worry about the interconnectors, it would be that if the whole 2GW link supply from France failed suddenly it exceeds the 1400MW generating loss that the grid can currently stabilise. I don’t actually worry about that because I assume someone has thought of it before me.

  7. Graeme No.3 says:

    thank you for a most interesting article, and I agree.
    I wonder if not only the UK but other countries are all expecting reliable supply from the interconnectors and neglecting to install sufficient reserve capacity?

    Of course the resulting blackouts would be blamed on an unusual (unanticipated) combination of circumstances, as they always are.

  8. Olav says:

    Attached is links to Danish interconnectors and Norwegian reservoirs
    The wind was very good now so el price went negative.for a few hours (approx. 50 hours a year) Germany was exporting into Denmark do to similar wind conditions. Denmark was exporting to Sweden and even more to Norway. The beauty of hydro production from reservoirs is the cheapest storage that exists, Just save water and let the wind or cheap import supply demand..
    On January 2 and 3 was wind production in Denmark close to 100 % of demand. They was still running power statins due to needed heat delivery:
    Interconnectors to somebody that can deliver on demand is preferable…

    • Olav: Thank you, interesting links.

      I agree that hydro storage is beautiful, but as Lars points out below there are presently interconnector limitations on how much hydro can be shipped south from Scandinavia. Are there plans to beef up existing interconnector links?

      • Askja Energy says:

        There are plans for a direct link between UK and Norway.
        Interconnector between UK and Iceland is also possible:

        • The Ice Link interconnector is one of a number of new interconnectors the National Grid thinks there is an “urgent” need for “to maintain energy security, flexibility and efficiency in UK”, which presumably means that in NG’s opinion there will be no energy security, flexibility or efficiency without them. I can see how interconnections with Iceland and Norway could be beneficial but it’s not clear how more links with France and Ireland and new links with Belgium and Denmark would help:

          • Euan Mearns says:

            Roger, National Grid makes its money from transporting energy around. So I imagine the more of it that travels the longest distance the better it is for them. The map looks like an electricity import model for the UK. What we need is indigenous primary energy production. We could get rid of all of this by building 15 new nukes in the UK. Safe and secure and indigenous.

            Interesting to note that CO2 transport and storage has a role to play – transport of CO2. National grid needs its wings clipped.

          • Electricity in in UK is generated dominantly by profit-seeking foreign-owned private companies, distributed by another profit-seeking private company whose ownership I have not yet been able to establish and regulated by politicians who appear to have lost control of their faculties. When you think about it it’s a miracle the lights are still on.

            Incidentally, all the links on the map except for Ice Link and Belgium, which is reportedly under construction, appear on Ofgem’s “shortlist”, which I think makes them part of the UK’s official “energy import model”.

  9. Graeme No.3 says:

    Ah! But will they deliver when you demand?

    • More important, can you quit delivering when you’re running out of power, as the UK seems to have been on 16 January 2013?

      I’ve been casting around for answers to this question and can’t find any provision in anyone’s interconnector regulations which allows for export shutdowns during emergencies. The purpose of interconnectors seems to be to a) minimize costs and b) postpone as long as possible the need for new capacity. There’s a lot of stuff about interconnector security but nothing about security of supply.

      So right now I’m guessing that if Fawley hadn’t been available the lights probably would have gone out in a million British homes on 16 January while the UK was still delivering ~500MW to Ireland, and it would have been put down to unscheduled plant outages, which indeed were the proximate cause.

      But as I say that’s just a guess. I could be quite wrong. Any expert opinions out there?

      • Lars says:

        “More important, can you quit delivering when you’re running out of power, as the UK seems to have been on 16 January 2013?”

        Roger, no expert opinion just an opinion.

        I have no idea about the French-British interconnector, but this is the case for several interconnectors in Europe. For instance, the four interconnectors between Denmark and Norway (Skagerrak 1-4 ) and the Dutch-Norwegian interconnector (NorNed) have a so called “capacity constraint mechanism” reserved by the Norw. TSO Statnett. It basically states that when there is lack of grid capacity in south-western Norway to supply at maximum levels to both the Netherlands and Denmark (0,7 + 1,6 GW), both interconnectors will be limited to get a fair share each. This will apply until the grid in the area is reinforced. Although this is grid constraint not generator it seems first priority for Statnett is supplying the Norw. grid which is quite natural.

        Also both the Baltic Cable between Germany and Sweden (0,6 GW) and the SwePol between Sweden and Poland (0,6 GW) are heavily restricted almost on a daily basis due to factors like wind intermittency, grid capacity and generator capacity particularly in Poland. The Baltic Cable I think must be regarded as a failure because it can`t send much power to Sweden when the wind is blowing a lot in Germany due to constraints in Germany which I don`t have a clear picture of now.
        I could have provided links but they are all in Scandinavian language.

        It would be very surprising in my opinion if the French and British TSOs don`t have similar arrangements. It makes no sense to black out your own grid, especially not due to DC interconnectors where flows are more easily stopped than in a huge synchronous AC grid like in Continental Europe.

        • Lars, that’s certainly a much more expert opinion than I could possibly deliver. Thank you.

          I plan to do some more work on this but have to finish tomorrow’s Blowout post first. Back later.

          • Lars says:

            Roger, thanks.

            As I said there are limitations to flow on several Scandinavian-linked interconnectors. I mentioned a specific Norwegian measure but there are also a formal cooperation between e.g Scandinavian TSOs. Due to a growing number of interconnectors it is increasingly demanding for the TSOs to regulate the flow in these cables.

            First, this is probably the main reason (apart from revenues) why some TSOs want a monopoly on building and running them, to be in control. They don`t want power companies to run interconnectors.

            Secondly, energy markets dictate that the flow goes from a lower priced area to a higher priced one. Of course the power producers want to maximize their profits utilising the capacities of the interconnectors, but this can be troublesome for the TSOs which also have the overall responsibility for grid security.
            The case with the French-British interconnector is a prime example. Good income for British generators in that case, but dangerous for National Grid risking a blackout.

            There are problems because between European interconnectors you have very different power systems in terms of: Peak power/off peak power times, capabilities of ramping up and down, intermittent power, fluctuations in consumption by outside temperature and more.
            In the Nordic electricity market this was solved simply by “ramping rules” in 2007 which are as follows:

            – maximum flow change for each interconnector is 600 MW/hour.
            – maximum flow change must be gradual and never more than 30 MW per minute per interconnector.

            This for instance means that for a 600 MW interconnector like SwePol or the Baltic Cable it will take at least 2 hours to reverse flows completely.
            Not a popular measure among the power companies but probably a necessary one.

          • Lars: Here are the Gridwatch UK export/import data for January 16. There don’t seem to be any ramping rules and the flows are jumping around all over the place. Can you make any sense of them?

  10. Hugh Sharman says:

    Thank you for another useful post, Roger! Good work!

    Fawley has closed, according to its owner, RWE

    Littlebrooke, the last oil-fired power station in UK will remain open until 15th March this year, according to the announcement it made last year at

    Yet at, its owner is currently saying it will stay open.

    At, bottom table, Grid is obviously depending on Littlebrooke to remain open until 31st December.

    It would be interesting to learn whether demolition of Fawley has started or whether DECC/Grid are paying RWE NOT to do this before they have sorted out the capacity issues of next winter and those of 2016 and 2017 after which the magical capacity auction for 2018 kicks in and the “market” will keep the UK out of trouble.

    On the subject of the inter-connectors, flows are all over the place during windy weather, of which there has been a great deal recently, as with the pumped storage. It is beginning to look like Denmark with strong outflows of electricity during the windiest weather.

    As long as UK does not build any more wind, it looks as if the system can cope. But that is not the case, of course. Amazingly, I cannot see the “dash for wind” slowing down during the electoral cycle following the UK election in May 2015.

    • Lars says:

      Roger: That graph certainly don`t look like planned ramping to me with the exception of the Irish interconnector. It looks like an emergency. On that morning there must have been an exceptional need for more electricity in both the Netherlands and France starting at about 5.40 a.m. National grid sent a combined 0,7GW (appr.) to those countries during a very short time and increasing. But the change of flow was much greater, about the double during the same time since the UK had been importing just before.

      I don`t know if this came as a surprise to National Grid because I haven`t been able to find out exactly when the cold spell began, but it looks like they were unprepared based on the erratic flows. Anyway France needed help from all neighbours during this time.

      It seems National Grid was able to reverse flows initially without Fawley which only started operating at about 1030 a.m. Dinorwig and other pump storage stations + gas turbines? If not what else? The fact that Fawley wasn`t started during the night instead indicates this was a surprising situation to National Grid.
      If this is the case it`s anyones guess if the British grid was at serious risk or not. If there was a failure in a big nuclear, coal or gas station simultaneously, well…

      Another interesting factor is that Fawley ceased operating at about 4.30 p.m, well before British peak hours. If the situation was tense earlier it must have been under total control at this time not the least because the Dutch had been able to ramp up production or import during the afternoon.

      • Lars: Here’s a plot of net interconnector flows to and from UK in January 2013 with minimum temperatures plotted below. Flows to and from Ireland are fairly constant, so what you are looking at is dominantly flows between UK and France/Netherlands.

        Power flows out of UK to France/Netherlands during peak periods when it’s cold but not when it’s mild, suggesting – what? That they have lower reserve margins than UK, or that UK power is cheaper? Ramping rates also tend to be higher during colder periods, suggesting – what? Shortages during cold weather, or just more erratic price spreads?

        I note also that between 0520 and 0525 on January 16 flow along the IFA link reversed itself by 1132MW (from plus 420MW to minus 712MW) in less than the five-minute Gridwatch reading interval. I assume you can do this without breaking something. 😉

    • Nick Perrin says:

      Thank you Hugh and all earlier for q & A this thread is very informative.

    • Hi Hugh

      Power exports from UK during the 2013 cold spell generally correlated with periods of low UK wind generation, the opposite of what one would expect.

      I suspect the UK held the capacity auction because the Powers that Be were just as confused over which plants were going to stay on and which weren’t as we common mortals.

  11. Hugh Sharman says:

    BTW, thank you Lars! Ever since Nordpool was absorbed into NASDAQ, I have lost the link to its Nordic reservoir status link! Will there ever be trouble here in the Nordic area if there is a repeat of the situation in the winter of 2010-2011 when every thermal plant in the area was running flat out to keep Norway’s lights on because of its critical shortage of water.

    Most of these plants are closed or are in the process of being lost!

    • Lars says:

      Hugh, I think I am more concerned about the future of Swedish nuclear than hydro reservoirs especially now with the unclear and potentially unstable political situation in Sweden. From what I have read the green party will stop the oldest nuclear reactors already in 2017-18 and you never know what kind of insane political deals can be struck now that the sole aim seems to be keeping the anti-immigration party “Sverigedemokraterna” from power.

      Losing 2-3 GW of baseload in 2-3 years time would mean Sweden will no longer be capable of securing necessary peak power in all situations no matter how much wind power they develop, they are barely self-sufficient regarding peak power today. Like in other countries (some) politicians seem to be out of touch with reality and without knowledge how much it takes to keep the lights on.

      If Swedish politicians want to drop some Swedish nuclear and continiue developing wind in the Nordic area, then imo they should install more capacity in existing hydro plants, ie. more reversible turbines to provide enough peak power and to pump water back when the wind is blowing. The existing reliable 13,5 GW of hydro on a cold winter day along with about 6 GW nuclear + 4 GW of thermal plants simply won`t do.

      It is indeed interesting times for all of us interested in the European power market 🙂
      If there will be a return in Europe to the colder winters of the 60s, 70s and 80s the full force of failed energy policy will strike mercilessly.

      • Euan Mearns says:

        Lars, I’m interested to see how Sweden’s ability to balance N European wind evolves when you begin to shut down your nukes 🙁

        To convert conventional hydro to pumped storage you need a large lower reservoir – which you may have in Sweden? But it can begin to mess with the hydrology of the rivers – in flood when producing, in drought when pumping.

        We’d be really interested to know what the ultimate balancing capacity is of Norway + Sweden? I suspect the Norwegians are happy to discuss building inter connectors to lots of countries since this will enable an auction of their finite balancing capacity.

        • Lars says:

          Euan, fyi I am Norwegian not Swedish so I know Norw. conditions better 🙂

          There has been done preliminary studies on balancing potential in Norway, both by the NVE (Norw. Ogfem, not available in English) and by CEDREN which I link to here. I think you might find the information there useful.

          NVE calculated the extra potential for upgrades without taking into account pump storage stations and came to this conclusion:

          “The 89 power stations studied by NVE had an average usage time of approximately 3,900 hours. If the usage
          time for each individual power station can be reduced to 2,000 hours by upgrading its power output, the total
          power output of these power stations can be increased from 17,000 MW to 33,500 MW. This is an increase
          of 16,500 MW. A reduction of usage time to 2,000 hours was selected to illustrate the potential for
          improvement. In some power stations the increase in power output could be significantly more than that
          corresponding to a usage time of 2,000 hours.”

          In this scenario Norway would function as passive storage mainly, switching off output when it blows or is sunny and the total installed hydro capacity would be about 46 GW where only about 5-6 GW are run off river.

          CEDREN`s study which includes more pumped storage in addition to increased installed capacity came to this conclusion:

          “In CEDREN’s HydroPeak project, three scenarios are described with regard to the export of balance power
          from Norway [6]. The main scenario involves increasing output by 20,000 MW. Table 3.3 shows that the
          output of the power stations studied in Chapter 2 can be increased by 18,200 MW without the water level
          changes in the upper and lower reservoirs exceeding 14 cm/hour. How long the power stations are able to
          deliver this power output will depend among other things on the current regulations regarding highest and
          lowest regulated water levels (HRWL and LRWL), as well as what strategies are adopted with regard to
          pumping in the case of pumped storage power stations. The figures shown in Table 3.3 are from the tables in
          Chapter 2, and in the case of some of the power stations the capacity agrees with Scenario 1 or Scenario 2.
          By including more cases in Southern Norway in addition to some in Northern Norway, it will be possible to
          increase the output of existing hydroelectric reservoirs by a further 1,800 MW to give a total of 20,000 MW for the whole country.”

          In Cedren`s main scenario the total hydro capacity in Norway would reach about 50 GW with peak demand in the country presently at 24,5 GW.

          • Euan Mearns says:

            Lars, thanks for the link to SINTEF report. I worked for a couple of years at IFE, lived in Norway for 8. Looking at some of the maps, I’ve skied over many of these lakes.

            Perhaps the most pertinent lines you write are the last 2. Norway could deliver 25 GW through inter-connectors, but for how long? Backup is about days and weeks, not minutes and hours.

      • Hugh Sharman says:


        Thanks. I completely empathize with you concern for what the Greens might demand in order to keep the Social Democrats and themselves in power.

        However, Sweden is by no means the only Scandivanian Government whose energy policy is driven by technically incompetent politicos. In a “normal” year, Finland, Norway and Denmark will supply “peak power” to Sweden.

        However, with the premature closure of Swedish nukes and Danish coal stations, the whole of Scandinavia will be in trouble if there is ever a re-run of the “dry” winter of 2010 – 2011. If I remember correctly, that happened several times from 1998 – 2010 but I have not time to research that now!

        • Lars says:

          Hugh, yes for instance both 1996, 2003 and 2004 were “dry years” in the Nordic hydro power system.
          I think the problem year was really 2009-10 with only about 5 GW of Swedish nuclear available and low reservoirs + record cold. That year resembles very much what the situation could look like without the oldest Swedish reactors from 2017-18 if the greens have their will.
          Closure of Danish coal stations doesn`t help the situation either as you point out. From what I know the biggest Danish coal block Åsnæsværket 5 is threatened with closure soon if not a capacity market is introduced. This is exactly the kind of large capacity we need in dry years.

          But it seems the Swedes are aware of the problem with intermittent wind even on the top political level now as they signal the winter capacity reserve may be kept beyond 2020:

          • Sweden will probably face a shortage of peak power as early as 2019 as utilities may start to close old atomic plants, grid operator Svenska Kraftnaet AB said last month. “The capacity in the system is vital,” said Baylan, a Social Democrat appointed last month after his party formed a government after the September general election. “I need to think about how it should work properly.”

            It’s nice to know that at least one politician in the world is thinking about it.

    • Lars says:

      “Perhaps the most pertinent lines you write are the last 2. Norway could deliver 25 GW through inter-connectors, but for how long? Backup is about days and weeks, not minutes and hours”

      Euan, I think it is pretty much implied in the text I quoted that these power stations have been selected for a closer study exactly because they can deliver power for weeks at a time with increased installed capacity, going from 3900 to 2000 running hours on average which is still a lot. In other words they are power stations with large upper and lower reservoirs and which do not interfere with other power stations downstream and without too many restrictions.

      The potential for pumping is obviously even larger but then with smaller reservoirs and/or more restrictions. For instance, I live a few kms from a large power station where it is totally possible to construct reversible turbines but where there are limitations on lower reservoir levels during the summer months, enough for it not to be considered in this study.

  12. Askja Energy says:

    Olav is of course absolutely correct about the beauty of hydro production from reservoirs. Therefore the UK should focus on interconnectors to Iceland and Norway. Note:

    • Olav says:

      I believe that hydro from reservoirs should be primary used for the short and perhaps “unexpected lulls”
      A large widespread wind carpet gives an accurate forecast of wind conditions ahead as each turbine is an observation post. Keep the old soon to be retired oil and coal fired generators ready to be fired up on more than 24 hours notice. When fired up they shold run at max efficiency load and any exess powe is sent to interconnectors towards Norway and Iceland to displace hydro reservoir drainage. Hot Standby/low load low efficiency is then avoided from “old” generators while resrvoirs gets filled free by nature. For the long “lulls” we need the old generators and oil and coal are the best as they can store a lot of fuel onsite. Gas is more difficult as additional gas for power may not be aboundant on a cold winter night without wind.

  13. Interesting strategy, Roger: use hard data about the UK and inaccurate forecasts about Germany. See:

    • Wow! I really touched a nerve with that one, didn’t I?

      And all I did was cite a couple of articles about Germany, which wasn’t even the subject of the post.

      I feel another post coming on ….

      • Graeme No.3 says:

        Another post? Looking at imports/exports from Germany for the relevant dates? After all Poland and the Czech Republic have been suppliers, and Denmark is always looking for someone to take their surplus wind supply.

        But that doesn’t address the main thrust of argument, that building inter-connectors is no guarantee of supply esp. if all countries are busy shutting down reliable sources in favour of non predictable sources.

      • I should add that, during the time the Roger was complaining about, Germany exported natgas to the UK, thus helping save the country from freezing:

        You’re welcome.

        • You’re welcome

          I’m sure my friends in UK thank you, but if you had done your homework – something you don’t seem to be particularly good at – you would have found that I’m actually an American living in Mexico.

          Thank you also for the link. In reading through it I came across this:

          “the event shows that natural gas is not completely reliable even during the shale boom, whereas renewables performed quite well last week.”

          Had a good laugh at that one. 🙂

          • Euan Mearns says:

            Roger, its cold in the UK today and we need lots of electricity. Not been above zero in Aberdeen despite all that CO2. I don’t think I’ve ever seen the wind output so low 😉 And look at gas – 21 GW.

          • Have Craig Morris send you some gas from Germany. 😉

          • Lars says:

            3-4 years back it would be the other way round: Coal would be 21 GW and gas 16 GW now. A repeat of the cold late winter and spring 2010 would be an interesting scenario to see if there would be enough gas available in the UK to make up for the lost coal power. Ah, I forget the altruistic Germans have some gas to spare for you.

  14. Euan Mearns says:

    Craig, I’m wondering if there is a special course that Greens go on to learn how to behave badly on social media and probably else where for that matter. This is a blog and myself and Roger publish a hell of a lot of information where we do our best to provide an accurate and balanced view. But we don’t always get things right and that is why we have a comments section.

    The socially normative and acceptable way for you to deal with any inaccuracies in this post would have been to detail these in comments that could then have been followed by an exchange of views. That way we all learn.

    For a year I have persevered with Greens and renewables enthusiasts hoping that they may bring something to the debate. I have now reached the conclusion that Greens have nothing to contribute to the energy and climate debates other than noise. And so we now have a pretty hard line on Green Trolls.

    What is anyone supposed to learn form your comment here? It is devoid of technical information and makes a squalid allegation against Roger. My only takeaway is that you are an advanced form of Green Troll promoting your own squalid web site. I’ve had a quick look at the article and didn’t learn anything.

    A copy of our commenter moderation policy is below. I have placed you on comment moderation. That means if you show up with technical commentary it will get posted. Green slime won’t. Incidentally, I suspect you don’t even know how poor your conduct is.

    We do not find the general standard of your comments to be contributing in a positive way to the discussion and your comments from now on will be subject to moderation. You can still post, but only your polite, on topic and informative comments will be published.

    • Biniput says:

      You are getting very close with that attitude to just banning anyone who disagrees with what you say. The link from Craig is a critique of this entry and has a lot to say to me. If you didn’t learn anything from that link I would seriously suggest giving up on pretending to be a blogger as you must take these things and deal with them.

      • Euan Mearns says:

        I presume you have read and understood the “anti Green Troll” legislation. And yet you post a comment that is devoid of technical content and merit. So here’s your big chance. Since you have read Roger’s post and Craig’s rebuttal, can you summarise for me and my readers where Roger was technically wrong.

        I would seriously suggest giving up on pretending to be a blogger


        Some of my posts get re-posted to over 20 blogs, get over 100,000 reads.

        Beware of moderation. I’m only interested in numbers.

        • Biniput says:

          Only interested in numbers eh? Well sometimes answers don’t need so many as logic will do. The central problem here is that shutting down certain power stations and opening other sources is a separate policy to inter-connectors and their construction. Also if the post Fukushima shut down of Germanys reactors was a cause of the 2011 outflows how could such a large loss of power have been covered in what looks like less than a month. Surely such a gap would have been closed over a longer period of time.

          • Euan Mearns says:

            Only interested in numbers eh? Well sometimes answers don’t need so many as logic will do. The central problem here is that shutting down certain power stations and opening other sources is a separate policy to inter-connectors and their construction.

            Of course I’m such a fool I didn’t see the logical connection. You I’m afraid do not seem to understand that you are simply blabbering rubbish.

      • Euan Mearns says:

        I hasten to add that I love a good argument and debate. I don’t mind people disagreeing with me at all. Its just that the terms of disagreement need to be clearly stated in technical terms that I can respond to.

  15. Biniput says:

    If there is only so much supply in terms of power stations or options in the UK then surely inter-connectors offer more options. How can this therefore create less stability or endanger reliability?

    • Euan Mearns says:

      The Greens have shut down our power stations on what as far as I know are bogus health safety and environmental standards. What rationale do you have for the UK importing 2.2 GW average in December?

      • Biniput says:

        What has any of that got to do with inter-connectors? Why do we import in December? Because it’s cheaper. You seem to forget who does the buying into the Uk and who does the indigenous generating and that they are two different entities. If you want the rational please stop asking people like me and get onto interviewing people from the Electric grid or operators instead of filling in all your knowledge gaps with supposition?

        • Lars says:

          “Why do we import in December? Because it’s cheaper.”

          That is probably true. Britain is importing 1-2 GW constantly from France it seems. But on the other hand one might ask why has British electricity become so expensive that imports are cheaper most of the time? Could it have something to do with the closure of coal plants and reliance on more expensive gas plants in recent years?

          British power operators are dominated by foreign companies that close British coal plants but build new ones at home. Why is that? In Britain they build more gas plants further enhancing dependence of natural gas. Britain is probably a prime example that the energy sector is too important to let foreigners without the best of national interests in mind dominate, and in addition you have the green push to set up windmills everywhere.

          And when it is blowing a lot in the UK the interconnector to France is still not used to export surplus power like Germany does, instead windmills are paid to be curtailed at the expense of the taxpayers. Yes, I would love experts from grid and power operators to answer these questions/claims.

    • How can this therefore create less stability or endanger reliability?

      There’s a post on this a few feet farther up. Please read it.

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