Energy from the ocean

Over 70% of the surface of the Earth is covered by water. The ocean is subject to the impact of wind, tides and ocean currents and thus carries with it large quantities of energy.

Researchers, inventors and engineers worldwide are working to develop technology that can transform the energy in the ocean into electrical energy that we can use.

Wave power

When the wind blows over the ocean, waves are created. The energy in the wind creates the waves by the wind setting the water into motion. In a wave power plant, the waves' energy is captured and transformed into electricity.

In many countries, people are working to develop wave power plants that harness the forces of the ocean, for example in a storm, and are able to transform wave energy into electricity in an efficient manner.

The future

In principle, none of the electricity in the grid today is generated by wave power. However, this may change in the future, and wave power could become an important supplementary source of renewable energy.

Tidal power

The tide is the name of the regular rises and falls of the water in the oceans twice a day on account of the force of attraction of the moon on the enormous mass of ocean water. When the water in the ocean rises and falls, tidal currents are produced. A tidal power plant transforms the energy in the difference in level or in the currents into electricity.

The future

At present there are only a few tidal power plants in the world. However, this may change as tidal power plant technology is developed and there is a greater need for renewable energy generation.

Osmotic power

The ocean consists of salt water, while rivers and lakes consist of fresh water that does not contain anywhere near as much salt. When a river flows into the ocean, salt water and fresh water mix. If a membrane is placed between the salt water and the fresh water, a phenomenon called osmosis occurs; the fresh water flows through the membrane to the salt water side. Increased pressure is produced on the salt water side that can be used to drive a turbine that in turn drives a generator. This is called osmotic power.

The future

Osmotic power is a new energy source that is still at the research stage. There are no osmotic power plants generating large quantities of energy today. However, tests are taking place so this could become an interesting renewable energy source in the future.

Ocean energy and the environment

Wave power, tidal power and osmotic power are renewable energy sources that are estimated to have relatively little impact on the environment compared with many other energy sources as the energy transformation itself does not produce any emissions.