Inter Connectors – who needs them?

There’s only one thing that renewable energy advocates like more than plastering hillsides with turbines and that is building transmission lines and inter connectors, deemed necessary to make it all work.

In this short post I want to draw attention to a news item (in Danish) I received courtesy of Hugh Sharman detailing a complaint that the Danes have with their German neighbours. The Germans are blocking electricity exports from Denmark, evidently in contravention of EU free trade rules.

According to latest data from the Energy Watchdog, the inter connector between Denmark and Germany is just available for Danish exports for 14% of the time.

So what’s going on here? If existing inter connectors are not being used, what is the point in planning and building more?

Figure 1 Map of the European high voltage grid courtesy of Energyanalyst showing the inter connections between Denmark, Germany, Norway and Sweden. Figure 2 shows the actual flows for May 2014.

One can but speculate the reasons for the Germans turning down Danish electricity. It seems likely that when it is windy in Denmark it is also windy in northern Germany and they have a surplus to sell at the same time and are therefore not interested in buying from Denmark. German flows into Denmark may not face the same resistance since the Danish grid is open to Norway and Sweden with flexible and dispatchable hydro generation that can be switched down to absorb German wind. This is effectively a manifestation of wind blowing everywhere that has been discussed many times on these pages.

The Danes are not happy and the Energy and Climate Minister Lars Christian has undertaken to take up the matter of the closed border with his German counterpart observing that Denmark is not the only closed electricity border that Germany has with its neighbours. There is also a move to take this up with the EU. I dare say the politicians and bureaucrats are about to learn that the physical world obeys physical laws and not the laws made in Bruxelles.

Saturation with wind power will only get worse as time goes on and cannot be solved by building more inter connectors. In fact, as wind saturation grows, the need for inter connectors between wind producers will decline since all will experience over-supply simultaneously. The only connections that make sense are between wind and hydro producers that can provide limited load balancing service.

Figure 2 The map shows power flows (GWh) for May 2014. There are a large number of interesting observations to make that go beyond the scope of this post. Something to discuss in comments! For example Nuclear France exported 6625 GWh and imported 301 GWh. Norway exported 897 GWh to Denmark and Holland while importing 9 GWh. Map from Energyanalyst.

So why are Europeans planning on building more, lots more inter connectors? The explanation lies in the central plan. There is a presumption in the EU that renewables are beneficial. And there are legally binding targets to be met for renewables penetration and CO2 reduction. Unelected bureaucrats in the UN and EU have seized control of a large and fundamentally important part of the OECD economy. And there probably isn’t a scientist among them.

There is a belief that greater connectivity of the grid is required to enable the ebb and flow of wind and solar between countries. This belief is in fact one of those semi-mythical half truths, partial solutions. The engineers who may have pointed this out work for the grid operators who are naturally keen to see the grid expand regardless of whether it makes sense or not. For so long as the consumer mug is there to foot the bill the grid operators are happy to take their money. The other engineers who may point this out work for universities and NGOs on projects aimed at delivering the central plan. Their livelihoods are dependent on the plan and the more difficult it is to deliver the more money there is to be made. The central planners of the Soviet Union would have been proud. But all this of course amounts to massive mis-allocations of capital. Worse than that, the capital is being spent to hobble one of our most vital resources – dispatchable electricity.

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35 Responses to Inter Connectors – who needs them?

  1. Joe Public says:

    Thanks Euan, for slotting another piece into the European energy jigsaw.

    Here’s a recent Grauniad rose-tinted take on the situation:

    So much power was produced by Denmark’s windfarms on Thursday that the country was able to meet its domestic electricity demand and export power to Norway, Germany and Sweden.

    On an unusually windy day, Denmark found itself producing 116% of its national electricity needs from wind turbines yesterday evening. By 3am on Friday, when electricity demand dropped, that figure had risen to 140%.

    Interconnectors allowed 80% of the power surplus to be shared equally between Germany and Norway, which can store it in hydropower systems for use later. Sweden took the remaining fifth of excess power.

    “It shows that a world powered 100% by renewable energy is no fantasy,” said Oliver Joy, a spokesman for trade body the European Wind Energy Association. “Wind energy and renewables can be a solution to decarbonisation – and also security of supply at times of high demand.”

    • Willem Post says:

      “….which can store it in hydropower systems for use later.”

      This is the kind of thinking that fools lay people.

      NOTHING is “stored for later”. The only thing that happened is Denmark sends a lot of low-price energy to Norway, and Norway reduced the flow of water through its hydro turbines.

      Norway will use water to make energy to send TO Denmark when prices are much higher, such as on low-wind daytimes with high demands!! Good for Norway, bad for Denmark.

      • Hugh Sharman says:

        Willem, imported wind at distress prices from Norway does allow the Norwegians to curtail their dam-sourced hydropower and “use it later”, as Euan rightly wrote. And of course, enjoy the much higher price for exporting this than they pay when mopping up surplus wind energy.

        With Sweden’s mostly run-of-the-river hydro, this national benefit is not so obvious!

        • Euan Mearns says:

          With Sweden’s mostly run-of-the-river hydro, this national benefit is not so obvious!

          Hugh, didn’t know that. Why do they do it? Why use someone else’s wind when you can use your own effectively free hydro?

          • Willem Post says:


            Viking solidarity is strong in Scandinavia.

            They help each other, which is good.

            But, as a result Denmark went off the deep end regarding excessive wind turbine build-outs, that, in my opinion, often do more economic harm than good.

            Telling that to the Danish government is heresy.

            It rather fires talkative acoustic professors to keep the lid on than face facts.

            I wrote another article dealing with the US using energy efficiency and build-outs of wind and solar, so the US primary energy would be reduced by about 50%.

            The costs are out of this world.


          • Lars says:

            Euan, Sweden also has dams, a lot of them. Although they are mostly constructed in river systems with relatively low head they contain a lot of water. Of Sweden`s hydro about 40% is pure indispatchable run of river, the rest is reservoir hydro (total about 16,5 GW remember). If they can buy Danish wind power at discount prices in the summer and autumn it makes sense to save water behind the dams and re-export it to Danmark and also to Finland, Germany and Poland in winter when prices are higher.

            Buying cheap surplus power from abroad multiplies the value of storage reservoirs, especially if you can store the water long term between seasons. “Viking solidarity” sounds sweet, but I don`t know 🙂

          • Euan Mearns says:

            Thanks Lars for that clarification.

  2. The Germans are blocking electricity exports from Denmark, evidently in contravention of EU free trade rules.

    And Germany’s other neighbors are taking steps to block electricity exports from Germany. This from Blowout Week 84:

    Germany’s shift to renewable energy has been hailed as an historic policy move — but its neighbors don’t like it. The country’s move away from nuclear power and increase in production of wind or solar energy has pushed it to the point where its existing power grids can’t always cope. And it’s the Czech Republic, Poland, the Netherlands, Belgium and France that have taken the brunt. “If there is a strong blow of the wind in the North, we get it, we have the blackout,” Martin Povejšil, the Permanent Representative of the Czech Republic to the EU said at a briefing in Brussels recently. Germany’s north-south power lines have too limited a capacity to carry all the power that is produced from wind turbines along the North Sea to industrial states like Bavaria or Baden-Württemberg and onto Austria. That means the extra electricity is shunted through the Czech Republic and Poland. To put an end to the often unexpected power flows from Germany — so-called loop flows — the countries are taking the matter into their own hands. Concerned about the stability of their own grids, additional costs and the ability to export their own power, the Czechs, for example, are installing devices to block the power from 2016 onwards. Poland is also working on the devices, known as phase shifters, and expects to have some operating this year. To the west, the Netherlands, Belgium and France have also installed phase shifters to deal with the flows.

    Eventually power will flow freely through interconnectors only when no one has any spare power to feed into them and everyone will block everyone else when everyone has a surplus.

    • Willem Post says:


      “Eventually power will flow freely through interconnectors only when no one has any spare power to feed into them and everyone will block everyone else when everyone has a surplus.”

      And the moon is made of cheese!

      Brussels will be happy, as all will have the best of both worlds, and peace will reign ever after.

  3. Willem Post says:


    You article is right on.

    I have been saying this for years, and people looked at me as if I were from another planet.

    It is completely incredible that Brussels folks can maintain such fairy tale nonsense with a straight face and get away with it for years.

    It smacks of the Catholic Church and its doings before Martin Luther.

  4. dc says:


    Tyranny is a term often used as descriptive of despotic acts, Whilst the UK is undoubtedly facing looming supply problems, it’s astonishing that the long-term known closure now recently confirmed of near 2GW Longannet – a third of Scottish peak demand – raises just a tiny but well spun blip across government/media.

    By 2025, as slated, both Hunterston B and Torness, gone – replaced by… an increase from current 7GW wind to 16GW wind. Easy, innit?

    I’m not suggesting that’s impossible. It could just be that a future, uniquely capable physico-chemist might sometime soon resolve the fundamentals of *Kit Carruthers and sequestration – sorry, carbon capture and storage – but as ‘science’ and ‘chance’ currently understand it, there’s probably a better likelihood of our numbskulls learning how to bury the stuff before being reminded that 400+ppm is actually a good thing.

    * KC;s a ‘mutual friend’ (apparently) on a social media site

    • Euan Mearns says:

      dc, I’m not sure what to make of your comment. Your third paragraph is rather cryptic. The relationship between KC, myself and this site is tense.

      The closure of Longannet (2.4 GW) next year will be a landmark event. Scottish Power has given two fingers to Scotland. The nukes will likely get license extensions. At least Torness will.

      Who is to blame?

    • Scottish Power is just another name for Iberdrola. Iberdrola’s core power gen business is renewables, with coal gen a marginal part of the business (7% capacity) that doesn’t fit with their image as a ‘clean’ generator. The decision not to award Longannet with £1bn from the Government was, I’m sure, in part down to Iberdrola being not particularly interested in CCS even when Scottish Power originally were (prior to being taken over). Cockenzie has been shut, and I think the closing of Longannet also suits Iberdrola; I doubt they put up much resistance to the economics of it. Of Iberdola’s global coal generating capacity (7% total capacity), Longannet makes up over 72% of it. Not for long.

      By the way, I have no idea who “dc” is, but they are welcome to contact me through social media if they have something to discuss with me.

  5. gweberbv says:

    Here you find the story in English:

    Upgrade of north-to-south power lines within Germany is going too slow. It is good that Denmark is complaining about that. But I fail to see a principle problem at the moment. Of course, we will need much more interconnection capacity and much more transmission lines (within the countries) to transport energy from the generation ‘hot spots’ to consumers – over distances of 1000 km and more. And connection capacity that was idle last year might be absolutely necessary next year, after a more NPP and fossil fuel plants were shut down.

    • Lars says:

      More interconnectors between northern and southern Germany are among the ones that make sense, but they are obstructed by angry German citizens and local authorities. I wonder who will win in the end and just how much saying the EU has in Germany. The EU can with legislation shut down vital coal plants in let`s say the UK, but apparently can`t command new interconnectors in Germany. It shows who`s the boss.

      • Günter Weber says:


        the construction of the transmission lines within Germany is already fixed by federal law. What is happening now are some fights on the regional level, where exactly to build them and which parts will be underground and which not. Unfortunately, such delays are more or less inevitable in a country that has a federal structure.

        Another example (outside of power production) is the Fehmarn Belt connection. Looks like when the tunnel is finished one will still have to wait a few years, before the German side is able to provide a good highway and train connection to it. Again one can only hope that the Danish side will push the German authorities.

        • Owen says:

          The EU or Germany dont own the German environment, the German citizen does. This is enshrined in law.

          You cant just push heavy lines through areas of heritage and beauty. So thankfully, the residents living in these regions are standing up against this.

      • Euan Mearns says:

        Lars, I forgot to mention that point in my post. The Bavarians are adamant they don’t want the N-S power lines. I visited S Bavaria last year. Its a beautiful and extremely prosperous part of the world. In the whole week we saw only a single wind turbine, and that was near the airport. I wasn’t looking out for power lines.

        Scotland is literally being plastered with turbines and power lines. I don’t understand how a government could actually promote the destruction of their country in this way in the name of environmentalism. There is a huge amount of and growing ill feeling. But the majority live in cities and are unaffected and don’t mind. Democracy rules.

  6. Owen says:

    These interconnectors have terrible payback periods, like this one in Ireland has a payback of at least 22 years.

    The private sector would not touch these projects with a 200 metre wind turbine.

    • Günter Weber says:

      20 years is awesome for large-scale infrastructure. Get real, man!

      The Øresund Bridge is crossed by around 30 million people each year. Yet it will need between 30 and 40 years to pay back construction costs.

      • Roberto says:

        The difference is that the bridge improves the lives of everybody, while interconnects necessary only to balance intermittent renewables don’t… plus, isn’t it true, as per green mythology, that ren electricity will be cheaper and allow us all too save tonnes of money?

        Logic, please.

      • Owen says:

        When the alternative is everyone taking a boat of course its a good payback. But when the alternative is building a power plant, its a bad payback.

  7. Syndroma says:

    Crimea needs the interconnector! 😉
    300 MW by the end of the year, 1.2 GW next year.

  8. Rob says:

    On the topic of Scotland does anyone have an update on interconnection between England & Scotland. Will the link be upgraded

    • Euan Mearns says:

      Rob, yes links are being up graded but I don’t have the details to hand. Scotland once exported about 40% of our electricity to England – good eh? Energy exporters tend to be rich. Once Longannet closes next year, Scotland will be dependent upon imports from England for some of the time.

    • PhilH says:

      The Western HVDC interconnect, between Hunterston on the Clyde and Deeside in N Wales, with a capacity of 2200MW, is under construction, with operations due late next year.

      The Eastern HVDC interconnect, between Peterhead near Aberdeen and somewhere in NE England, with a capacity of about 2000MW, is still in planning, with a view to being operational in the early 2020s.

  9. jim brough says:

    Denmark invested in and exported wind turbine technology to the rest of the world but it’s neighbours may not be able cope with its gross over-supply when the winds blow.
    That is Denmark’s problem.

    • Willem Post says:


      Consider Denmark being the gun seller, and now the gun seller points the gun at Denmark.

      Denmark is reaping what it sowed.

      If nearby countries say enough to German energy exports, Germany will reap what it sowed.

      • jim brough says:

        I don’t know what you have in mind when you say that Germany will reap what it sowed.

        For many years Germany subsidised its coal industry, had a good nuclear electricity supply until it went to subsidised solar and wind electricity, decided to shut down its nuclear electricity which has a much better ERoEI than the rest and has the lowest carbon footprint of all electricity generation technologies………if we are truly worried about anthropogenic global warming or climate change caused by CO2 emissions.

        Australia is a dry continent but its hydro-electricity output per capita is about twice that of Germany. Check the International Energy Agency statistics.

      • jim brough says:

        What do you mean ?

        • Willem Post says:

          I mean Denmark decided to have a national wind energy goal, benefit Vestas, etc., at the same time, and do some smug RE chest beating, advising others what to do.

          However, Denmark overdid it, now has too much wind energy when it is windy around Denmark and all around the North Sea.

          Exporting the energy to Germany, when Germany is trying to export its winds energy, is like two trucks heading in the opposite direction on a one-lane road.

          That people did not foresee this at least 5 or 10 years ago, is beyond me. What WERE they thinking?

          As I said, you reap what you sow.

          • Jim Brough says:

            Thanks for that Willem, I agree with what you say.

            I live in Australia where interconnectors have to cross a continent, not a little bit of Europe. Sending wind electricity from South Australia to pump water uphill to a hydro dam in the Snowy Mountains incurs energy transmission losses and a lot of additional expenditure on transmission infrastructure. A nice little earner for a technology which is subsidised by the taxpayer.

            Re hydroelectricity I have looked at per capita output and find, according to IEA stats that the dry continent of Australia’s output is almost double that of Germany, a land which extols solar and wind.
            Denmark’s solar output is zilch. Crazy !

            The whole caboodle is governed by politics, not the realities of engineering.

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