Several online journals published the outstanding achievements of wind power production in Denmark for the last year. The main results briefly: in 2015 wind turbines generated 42 percent of the total domestic electricity consumption in Denmark, which consisted of a 55 percent share of wind production from total consumption in West Denmark – covering the Jutland and Funen areas – while this figure was 23 percent in East Denmark. (These areas are shown in the main Figure 1) The total domestic electricity consumption comprises the total domestic production and the net import – the difference between import and export. Therefore these numbers are even more impressive if we consider the fact that Denmark was a net electricity exporter throughout the previous year – the annual sum of export exceeded the annual sum of import – which indicates that the share of wind production from total domestic electricity production has exceeded the 55 percent level (it was almost 57%). Furthermore, throughout the year, 1460 hours of excess wind output was generated in West Denmark – that is the hourly difference between wind production and load. This means that in average one in every sixth hours the turbines produced more electricity than that was consumed. And most remarkably, there was a whole day in West Denmark, when the central power plants did not generate electricity, thus the consumption was ensured by small-scale power plants, wind generators and import from the neighboring countries.

After I read those articles I was wondering how far Denmark could go with increasing its wind penetration, what could be the opportunities and barriers of the further improvement? Well, I am not aiming to discuss every aspect of these questions and not even to provide any specific answers for them, but to raise some concerns which I think Denmark will have to face in the near future.

First of all we have to see that the close location and the large interconnection (capacity) toward the Norwegian hydropower plants encourages the wind penetration development in Denmark, as they can take and store the increasing amount of excess wind (see Figure 2) and can support during the windless period (during 2015 more than 18% of the domestic production has been covered by import). However, as Denmark will phase out its fossil-fuel burning power plants (Danish Government, 2011) and will rely more on intermittent renewable sources, the significance of this relation will increase. On the other hand, besides its existing power link to the Netherlands, Norway aims to build new interconnector lines towards North Germany (NordLink and NorGer) and also towards the United Kingdom (NorthConnect and NSN Link).

Thus Denmark might have to reconsider its strategy.


Figure 2 The annual quantity of and the number of hours when excess wind electricity was produced in West Denmark (own compilation based on data provided by

As Cosseron et al. (2014) show in their spatial analysis on wind availability and variation, there is a high correlation in wind intermittency in the North Sea region, which indicates that the operation of wind turbines in the Netherlands, North Germany and Denmark are simultaneously affected. Thus concurrent wind power production (or the lack of wind) can result in high competition between these regions on the future pan-European electricity market.

Throughout the periods with excess power generation in Denmark, the wind turbines in Germany and in the Netherlands will most likely operate as well, which could decrease the market prices, especially if congestion occurs in the power cables towards central- and southern Europe that makes the electricity transportation more difficult to other directions. Conversely, due to the increased linkage, Norway might also strengthen its strategic options during windless periods as the demand for Norwegian hydro power increases. In this possible future power system Denmark could decide to import more expensive hydro power from Norway or nuclear and fossil fuel generated power from Sweden, or to produce electricity domestically. Either way the Danish market prices might be expected to rise and – as the wind penetration further increases – so does the need for additional expansion of interconnector capacity (e.g. the planned Viking Link).

This is of course only one possible future scenario for the Nordic power system and for Denmark, but the above mentioned topics might be worth considering: If Norway expands its connectivity towards new markets, will that result in higher competition for Denmark? Will the market prices increase? Is it still sustainable to rely on such a high level of international electricity trade? If wind availability is similar in these countries, will that strengthen competition even more? If so can Denmark undertake to import electricity based on fossil fuels? Is this acceptable in a country where there is such a high focus on environmental consciousness?

All these questions could be reconsidered by taking into account the possibility of building energy storage systems inside Denmark – therefore trying to meet domestic demand by inter-temporarily shifted supply, in addition to the spatial allocation. In order to have a full understanding of the different options detailed analysis of costs and externalities is needed.


Cover Photo: Figure 1 Bidding areas in the Nord Pool region (source:

Danish Government (2011) Our Future Energy, Danish Government, ISBN-printed: 978-87-7844-915-3, ISBN-e: 978-87-7844-917-7, or available online: , accessed: 5th February 2016.

Cosseron A., Schlosser C.A., Gunturu U.B (2014) Characterization of the Wind Power Resource in Europe and its Intermittency, MIT Join Program on the Science and Policy of Global Change, Report No. 258, available at:, accessed: 5th February 2016.

Data source; website:, accessed: 5th February 2016.

Referred article and website via hyperlink:

Neslen, Arthur: Denmark broke world record for wind power in 2015, The Guardian, 18th January 2016,, accessed: 5th February 2016.

O’Connor, Lydia: Denmark Just Broke The World Record For Wind Energy, Huffington Post, 18th January 2016,, accessed: 5th February 2016. New record-breaking year for Danish wind power,, 15th January 2016,, accessed: 5th February 2016.

Nord Pool Exchange website:, accessed: 5th February 2016.

4C Offshore Ltd.: Norned interconnector, 4C Offshore Ltd.,, accessed: 5th February 2016.

Statnett: The NordLink Cable to Germany, Statnett SF,, accessed: 5th February 2016.

Statnett: Statnett Enters into the NorGer Project, Statnett SF,, accessed: 5th February 2016.

Statnett and NationalGrid: NorthSea Link, Statnett SF,, accessed: 5th February 2016.

NorthConnect, NorthConnect Project website,, accessed: 5th February 2016.

European Comission: Annual Progress Report on the Internal Energy Market for Electricity and Gas, and the Implementation of EU Law. European Comission, Energy,, accessed: 5th February 2016.

Schlandt, Jakob: GUEST BLOG: Auf Wiedersehen Austria, the death of the European power market dream?, Energy and Carbon,, accessed: 5th February 2016.

NationalGrid: Viking Link, NationalGrid,, accessed: 5th February 2016.