To accelerate the deployment of sustainable energy, phase out fossil energy smoothly and, at the same time, cut energy consumption while maintaining a secure, available and affordable energy supply. This is the ambition that prompted ECN and TNO to cluster strengths. ECN part of TNO has eight innovation programmes. One of the programmes is 'Towards large-scale generation of wind power' - five questions and answers.
In order to achieve the Paris climate targets, it is necessary to speed up the energy transition. This requires technical, social and policy innovations. ECN part of TNO is taking up the challenge by implementing eight innovation programmes in the coming years, together with Dutch industry, research institutions and the government. Peter Eecen, Programme Developer Wind Energy at ECN part of TNO, answers five questions about the programme 'Towards large-scale wind power generation'.
1. What is the aim of the programme 'Towards large-scale wind power generation'?
"We are developing technology to generating 50 gigawatts of offshore wind energy in the Dutch part of the North Sea, at low cost and with the participation of the entire Dutch industry. 50 Gigawatts of offshore wind power can provide the energy for 50 million households. That is much more than Dutch households demand, but we also need wind energy, for example, to electrify the chemical industry. In addition, we will continue to work on cost reduction as additional costs are incurred for energy system integration, hydrogen conversion, energy storage and longer transportation lines."
"We are developing technology for generating 50 gigawatts of offshore wind power"
2. How can ECN part of TNO make wind energy cheaper?
"Larger turbines are one of the main drivers to reduce costs. We develop knowledge to make this possible: from anchoring on the seabed to the aerodynamics of the blades and from maintenance of turbines to the connection to the electricity grid. For example, we support developers of wind farms in determining the amount of wind power at the North Sea. There will also be a time when we will have to connect the parks to a grid of high-voltage direct current (HVDC). In this context, we are working on the design of future grids and the synergy with existing infrastructure in the North Sea."
3. What are the challenges involved in the design?
"As the turbines grow larger, the foundation piles become larger and heavier. Think of 20 metres in the sand, 20 metres under water and 10 to 15 metres above the water level. The diameter is even heading towards 10 metres. The piles are made entirely of steel. For this reason, only specially adapted vessels can lift and install them. The turbines are subjected to turbulent winds, which means that all components are continuously handling dynamic loads. Our models enable them to be designed as light and cheap as possible, while enabling them to keep operating as long as possible."
"We see opportunities to combine seaweed cultivation with offshore wind farms"
4. How do you reduce maintenance costs?
"Together with the Dutch offshore industry, wind turbine manufacturers, rotor blade manufacturers and energy companies, we are constantly developing new technology. We also do this with companies in Taiwan and China, where there is a great need for knowledge. Every five years there is a new generation of turbines that is twice as large. They must be made lighter and more efficient, otherwise it will simply be too expensive. We are also developing knowledge to optimise wind farms. By slightly reducing the power of some of the turbines, the entire wind farm has a larger overall yield and maintenance costs can be reduced even more."
5. Do wind farms also do something in return for nature?
"Because trawling is constantly churning over the North Sea bottom, the fauna has no chance to take root. Around oil platforms you can already see that there is more life than away from the platforms. This is because plants can attach themselves to the fixed structure. The stones around the foundation piles of wind turbines also offer excellent solid ground. We are also thinking of developing artificial reefs, where structures are being built, on which even more flora and fauna can grow. In this way, we ensure that a living underwater environment is created that is favourable to nature. Finally, we see opportunities to combine seaweed cultivation with offshore wind farms."
"By adjusting some of the turbines to produce a little less power, the entire wind farm produces more overall and maintenance costs are reduced even more"
Wind turbines larger than 15 megawatts
Don Quixote fought windmills with shafts of 6 to 7 metres high and rectangular blades - nowadays everything revolves around size and aerodynamics. A glass epoxy blade that is twice as big delivers four times as much power. However, by using the same technology means it is eight times as heavy and doubles the price per kWh. For turbines larger than 15 megawatts, ECN part of TNO is therefore developing innovations that keep the blade light as it gets longer. The researchers develop and validate their computer models in the wind tunnel and perform field tests on research turbines in the Wieringermeer in the Netherlands. In doing so, they are entering completely new areas of aerodynamics, with large aerodynamic profiles at relatively low speeds, something the aircraft industry has never had to deal with.