Outlook for the development of offshore wind power in the North Sea
Thanks to its hydrocarbon deposits, the North Sea occupied a key place in the global energy landscape since the first oil shock in 1973. Despite the drastic diminution of fossil reserves the region has managed to keep a strong position in that energy landscape through its renewable resources. Indeed, wind farms have multiplied in the North Sea since the 2000s and projects allowing electricity storage, such as "Power-to-Gas" (P2G), are emerging. Collaborations between the countries bordering the sea are being developed in order to optimize resource exploitation. Beyond the proliferation of projects, what is the real potential of the North Sea in the energetic transition? And how do bordering countries organize themselves to tap the resources?
The boom of offshore wind power allows to explore new partnerships in the North Sea
In a context of environmental protection, the renewable energies, among which offshore wind power, have undergone notable development during the last years. Indeed, from 0.92% of the European energy mix in 2001 (5.78% including hydraulic energy), they account for 4.89% ten years later (9.00% including hydraulic energy)1.
Among those energies, offshore wind power is a particularly promising technology since offshore wind turbines produce up to 60% more electricity than onshore turbines, due to the power and regularity of marine winds. This technology has thus acquired a significant position on the global energy scene. Since late 2012, offshore wind power represents 10% of all wind energy facilities - onshore and offshore included - i.e. a global power of 5,534 MW of which 90% is located in Europe, and more precisely in the shallow waters of the North Sea.
Figure 1: Share of offshore wind power in European electricity demand2
Source: Sia Partners
This rise announces very positive prospects: within five years, the installed power capacity in Europe will be multiplied by 8 and be able to meet 4% of the European electricity demand. In 2030, offshore wind power should account for 14% of European demand2.
In 2012, about two thirds of European offshore projects under construction were located in the North Sea and this proportion will remain stable in the coming years3. Indeed, even though more and more projects are being considered in the Atlantic Ocean and in the Mediterranean Sea - 9% in the medium term - thanks to the advancement of floating wind turbines, they will not be developed quickly enough to overtake the installed capacity in the North Sea.
The power of the wind and the proliferation of wind farms projects in the North Sea are not sufficient criteria to guarantee an optimal exploitation of that resource. Indeed, it is also necessary to develop a robust electricity grid in order to link offshore farms to the major energy consumption areas. In that view, several collaborations have emerged between the countries bordering the North Sea, which will enable the construction of a SuperGrid linking the different wind farms - and thus the bordering countries - between each other in the future. The main interest consists in curtailing local consumption peaks, and hence ensuring the security of energy supply in Northern Europe.
Figure 2: SuperGrid development in the North Sea for the exploitation of wind farms4
Source: Sia Partners
Figure 3: Grid projects in the North Sea, in progress or in operation5
Source: Sia Partners
The above tables present some examples of projects aiming at developing that offshore grid. Since the construction of such a grid is expensive, the main issue remains the amount of aid granted by the European Union. Initially set at 9.1 billion euros, the total budget for all the energy projects will finally be reduced at 5.2 billion euros. But sharing the budget between the several projects remains a complex issue until now6.
Wind electricity storage in the North Sea, a full-scale test
Beside its undeniable assets for wind power development, the North Sea also focuses on new technologies that would enable to store the electricity produced by offshore farms. Therefore, and thanks to the success of the current collaborations between bordering countries, new experimental projects are emerging.
One of the main ambitions of the North Sea is to develop the P2G technology. This process consists in converting electrical power into a gas such as hydrogen or methane. Then, this gas is injected into the gas transmission grid for domestic or industrial use. Thus, P2G allows to use the surplus of wind energy produced in the North Sea and to alleviate the problem of intermittency.
As a matter of fact, 11 European enterprises that are leading players in the sector - among which Fluxys, the Belgian gas transmission system operator (TSO), National Grid in the United Kingdom, or Open Grid Europe, the first gas TSO in Germany - have decided to join forces and study the feasibility and viability of P2G in the North Sea. Therefore, they formed the "North Sea Power-to-Gas Platform", an industrial platform dedicated to the promotion and development of the P2G technology in Northern Europe7.
Another electricity storage project was highly publicized in the North Sea: it consists in an energy atoll located off the Belgian coast, i.e. a circular artificial island installed on a sand bar which would contain a large well in its centre. Its working is based on the simple mechanism of pumped storage power stations (PSP). When wind electricity production will exceed demand, pumps will empty the well by using the surplus electricity. In periods of underproduction, the well will get filled, driving electric turbines which will generate electricity. This electricity will then be injected into the grid.
The atoll will be located at 3km of the Belgian coast and will extend over a diameter of 2.5km at the centre of wind farms. It will peak at 10m above sea level and its well will be 30m deep. Theoretically, the island could store the consumption of a large city during 24 hours8.
Currently, only the agreement of principle has been given to the creation of that energy atoll. Although its first operation is announced for 2016, its yet unknown costs might seriously hamper its construction.
Sia Partners - S. Fleischmann
(1) BP, BP Statistical Review of World Energy, June 2013
(2) The North Seas countries' offshore grid initiative - Memorandum of Understanding, 2010
(3) European Wind Energye Association, The European offshore wind industry - key trends and statistics, 2012
(4) Friends of the SuperGrid, Position paper on the EC Communication for a European Infrastructure Package, December 2010
(5) Those projects were not always launched to enable a better exploitation of wind resources in the North Sea, but still they could be a major asset to reach fixed goals.
(6) European Parliament, Connecting Europe: Trans-European Networks, November 2013
(7) Fuel Cells Bulletin, Euro cooperation for North Sea Power to Gas energy storage, May 2013
(8) Le Monde, La Belgique veut créer une île pour stocker l'énergie éolienne, January 2013