In principle, wind power is easy to understand. A turbine is powered by the wind. It’s easy to operate and maintain – at least on dry land. But how do we go about exploiting the wind that blows out at sea?
Video: Offshore wind
Offshore wind offers a clear advantage: Out here it blows more and more often. But that is also its drawback. And we need people out here. Working at sea can be quite challenging.
Norway is looking to develop large volumes of offshore wind energy. If we are to achieve our goals safely, we mus take the demanding conditions on our continental shelf into account.
Fixed and floating
Most offshore wind turbines in operation in the world today are fixed to the seabed. Fixed turbines have many types of substructures. Common to all is that they can only operate in water depths of about 70 metres or less. But 80 percent of the world’s offshore wind resources are located in deeper waters. The Norwegian Continental shelf is very deep in places. So, it’s here that the potential for floating turbines is greatest.
Many technologies are available, and more are under development. All floating turbines must have substructures that are sufficiently stable to withstand high waves, heavy storms and challenging wind conditions.
The energy produces by a turbine depends on how strongly the wind blows. Greater rotor area also contributes to increased production capacity, expressed in megawatts. An average offshore wind turbine can generate up to eight megawatts, which is enough to supply 2 500 Norwegian households.
Before the electricity can be used it has to be transported onshore. Transformer platforms receive alternating current from the turbines and convert it into direct current. This minimises output losses during transport over long distances. Once onshore, it is converted back to alternating current.
Why are we writing about offshore wind?
Regulatory responsibility for offshore wind power was delegated to the Norwegian Ocean Industry Authority (Havtil) in 2020. This authorises it to develop regulations for and conduct supervision of the development and operation of offshore wind farms.
A new regulatory framework for renewable energy production is now being prepared.