On 7 December 2009, ministers of the North Sea Countries (Germany, United Kingdom, France, Denmark, Sweden, the Netherlands, Belgium, Ireland and Luxembourg) announced that they would develop an offshore grid to enhance the integration of renewable energies such as offshore wind farms. The North Sea Offshore Grid will be one of the first steps toward a European super grid.
To this end, the OffshoreGrid consortium made up of eight organisations (3E, German Energy Agency, Institute for Renewable Energy/EC BREC IEO, Senergy Econnect, SINTEF Energy Research, National Technical University of Athens, European Wind Energy Association, Forwind - Centre for Wind Energy Research - University of Oldenburg) was established to perform a techno-economic study within the Intelligent Energy Europe programme aimed at developing a scientifically based view on such a grid along with a suited regulatory framework considering technical, economic, policy and regulatory aspects.
At the beginning of March, the OffshoreGrid consortium published a report saying that an offshore North and Baltic Sea electricity grid could be in place within 10-15 years.
Engineer, Dr. Achim Woyte, is Project Coordinator for OffshoreGrid. He joined 3E (a leading independent authority in renewable energy, energy efficiency and energy strategy) in 2004, where he manages 3E’s expert team for Renewables in Power Systems and Markets. Dr. Woyte is also a member of the European Technology Platform Wind Energy (TP Wind) and has authored and co-authored more than 50 scientific publications.
Interview date: April, 2010
Interviewer: Toby Price
To kick off the interview, could you explain why an offshore grid in the North Sea is needed?
An offshore grid is needed to bring offshore wind power to the centres of demand and to further integrate the power markets of Central-West and Northern Europe, and the British Isles. The main drivers for such a project go hand in hand: Europe wants a common power market with converging electricity prices and this requires sufficient transmission infrastructure to bring power to where it is scarce. Since a large share of new power generation will be from on- and offshore wind power plants in and around the North Sea, where resources are more widely available, this is where the large grid upgrades are needed. Therefore, all in all, the question is not whether we need an offshore grid but what it should look like.
This year will see the publication of the ‘Blueprint for a North Sea Grid'. Could you give us an indication of what this blueprint will involve?
The offshore grid will be modular and built in phases. In order to avoid stranded investments, a long term strategy is essential for the European Union to define effective incentives. I expect that the EC in its communication on the Blueprint will develop such a strategy.
For the next few years, the offshore grid design will, in my view, primarily be influenced by trade or commercial demand rather than offshore wind power development. Therefore, I first expect to see a recommendation for point-to-point connections, in line with the Ten Year Network Development Plan that was recently published for consultation by the European Transmission System Operators. For the years towards 2020 and beyond, we expect the establishment of large wind farms far from shore, e.g. on the Dogger Bank and in the German Bight. These wind farms will need electrical connection lines to shore that will be much larger than the interconnectors we will see till then. The need for grid connection of offshore wind will therefore evolve and become the main driver for offshore grid development.
In my view, the question lies in how far we should establish offshore nodes, possibly with connected wind farms. There is a trade-off between savings in joint infrastructure for grid connection and trade, the competition of different end purposes and the technical and financial risk associated with the installation of large transmission assets at sea. The OffshoreGrid project will answer where this trade-off happens and, of course, I hope the Blueprint will base its recommendations on our results.
What are the key challenges faced to get such a grid established?
For a grid where wind farms are connected at offshore nodes I see three main challenges:
- Compatibility of support schemes for offshore wind: who will pay the support for wind power generated in one sector and fed into another onshore grid?
- Regulatory treatment: can a wind farm connection be sized larger than needed for its grid connection in order to allow for trade?
- Cable allocation: does wind receive priority access to these cables, what if the wind generation deviates from the forecast?
The offshore grid in the North Sea is the first step to a larger Europe-wide super grid. What form will this super grid take?
If you like, the continental European transmission grid is already a supergrid: its physical extensions, the connected generation capacity and its reliability is unique in the world. But it was built for transporting power from bulk power plants to loads and it has not been upgraded much recently. Today, we need a grid that can interconnect generators and loads all over Europe and its neighbours and where we can control the flows more actively. High-voltage DC overlay grids as proposed by the Desertec consortium or by the Friends of the Supergrid organization will probably play a role here. However, the high-voltage AC grid will also need to be reinforced and enhanced for better control. We should not have the illusion that the overlay grid will one day solve everything. Transmission developments at the different levels go together and, frankly, the extent to which this will be high-voltage AC or DC is not yet my primary concern.
The word “offshore” is on everybody’s lips at the moment and Northern European countries, especially, are forging ahead to develop offshore energy. Which offshore energy projects are most attracting your attention and why?
The most interesting projects driving offshore grid developments are the ones far from shore. This is because generators situated more than 50 to 90 km from a high-voltage substation onshore cannot be connected with classical high-voltage AC cables. Moreover, such offshore wind farms will be quite large. We expect that these wind farms will be clustered at sea and connected to high-voltage offshore collector stations. At these stations, we will see large electrical equipment of several gigawatts in capacity, required to bring power to shore. This is why we consider these investment decisions as the triggering events for the development of offshore nodes.
In practice, these will be the British Round 3 wind farms and the later projects in the German Bight.
I also expect that floating wind farms and wave and tidal energy projects will influence the offshore grid once we see large commercial projects.
How important will offshore wind be to achieving the European Commission's 2020 targets and what more needs to be done to drive offshore wind growth?
In 2020, offshore wind power could contribute up to 5% of the European electricity consumption with a total installed capacity of 40 to 55 GW. More than 100 GW may be expected by 2030.
The European Renewable Energy Centres Agency (EUREC), the Europe Renewable Energy Council (EREC), and a host of European renewables associations are working tirelessly to ramp up Europe’s renewables industry, but do you believe the sector would benefit from the creation of a European Renewable Energy Agency (along the lines of the International Energy Agency or the recently created International Renewable Energy Agency), especially as cross-border renewables projects become more commonplace? If so, why? If not, why not?
I have no opinion on whether such an agency would be needed. This depends on its actual mission and competences and how it would be positioned in relation to the existing European agencies and interest groups.
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