"OWECOP's great advantage is that it can calculate the wind energy potential and perform a quick and clear cost analysis for every square kilometre offshore," explains ECN's Manuel de Noord. "The program combines a mathematical model with a geographical information system. The model gathers geographical information from a data base which contains details such as wind speeds, water depths, measurements of wave height and distance to shore. The model then calculates the investment necessary in material, preparation, management, turbine maintenance and the net energy output."
ECN researchers have applied the program to the Dutch sector of the North Sea, the Exclusive Economic Zone (EEZ). Some 10,500 square kilometres of the EEZ were recently appointed by the government as priority areas for offshore wind energy. Using this entire area could, in principle, supply all the electricity needed by the Dutch, some 110 TWh. Furthermore, between 10 to 15 TWh can be generated in the Dutch North Sea at a production price of EUR 0.10/kWh or under, based on Dutch renewable energy policy and technology that will be state of the art in 2005.
The software program could provide a much-needed boost to investor confidence in an area which is plagued by uncertainty. The Dutch government has given the go-ahead to two offshore projects: the 99 MW near shore wind farm (NSW) pilot to be built some 12 kilometres off the coast by a consortium of Shell, Nuon, NEG Micon, and NoordzeeWind; and a 120 MW truly offshore plant, Q7WP, to be built by a consortium comprising E-Connection, Vestas, Smit Maritime, ABB and Fortis Bank. But some 2.5 GW of further projects applications have been put on hold for three years while a concession system is worked out.
"At the moment it is not clear where we can build wind farms in the preferred areas. Current policy is to build on the first government identified priority area and when that is full you can apply for the second, but there is no agreement about what is full. According to criteria of no-go areas, such as shipping lanes, only one-fifth of the first priority area is actually available for wind development," says De Noord. This amounts to 300 square kilometres. Nevertheless, De Noord believes the government target of 6000 MW by 2020 is possible, "OWECOP shows that the potential of the first and second priority areas alone is in double figures. For 12.5 TWh you would need about 4 GW of installed capacity, around 8% of the total priority area."
Race for licences
As the race for offshore licences heats up -- and the interest is keen -- demand for OWECOP analyses is likely to grow, for not all sites within the priority areas are suitable for commercial wind production, says De Noord. "Within the priority areas there are sections where the water is around thirty metres deep. Obviously the most economically attractive wind energy will be generated in areas nearer to the coast and in shallower waters."
Because the program relies on a fairly complex linkage between an Excel work book program and a geographical information system (GIS), OWECOP will not be made commercially available. Instead interested parties will have to go to ECN for detailed analysis of potential sites. In principle the system will be available for analysing other national waters, "but then we will need detailed geographical information. When this is available the model can easily be adapted to assess costs and potentials in other countries," says De Noord.