Vågkraft

Vågkraft, or wave power, is a form of renewable energy that converts the kinetic and potential energy of ocean surface waves into electricity. It has a high energy density and a broad geographic potential along coastlines with strong wave climates, offering a complement to wind and solar power. Development aims to provide predictable, low-carbon electricity and to diversify the energy mix in coastal regions.

Technology for harvesting wave energy includes several approaches. Attenuators are long, floating structures that lie perpendicular to the wave direction and flex with the waves, driving hydraulic or mechanical power take-off systems. Point absorbers are compact buoyant devices that move with the waves, often vertically, relative to a fixed base, and convert this motion to electricity. Oscillating water columns enclose a chamber where wave motion pushes and pulls air through a turbine, while overtopping devices collect seawater in a reservoir and release it through a turbine to generate power.

Benefits include high energy density and localization near demand centers, and its potential to complement other renewables. However, the technology faces challenges such as high capital and operation costs, harsh marine conditions that stress equipment, corrosion and biofouling, maintenance in difficult sea states, and the need for reliable grid connections and power take-off reliability.

As of the early 2020s, wave energy is predominantly at pilot or demonstrator scale, with several projects tested in Europe, North America, and Asia. While no wave power device had achieved widespread commercial deployment, steady research continues into survivable designs, modular systems, and hybrid platforms to reduce costs and improve reliability.