Green Energy from Ocean Waves

 

 

Why wave energy? Technology Applications News About us

Why wave energy?

An existential threat

Anyone who understands the implications of this curve, the Keeling curve, should be frightened. It points to a disaster.

The latest UN report states that total greenhouse gas emissions must be reduced by 40% by 2030. And must cease by 2050. If not, severe and unpredictable climate change will cause irreparable damage to life and society.

The culprit is fossil fuel

 

Renewable energy needs space

Most of us tend to underestimate what is required of space if coal, oil and gas is to be replaced by wind and solar energy, the leading forms of renewable energy today.


Windmills in Norway. Credit: Hordaland Turlag

Windmills in Scotland. Credit: REUTERS/David Moir
Habitat destruction and loss, from agriculture, urban sprawl, logging, roads and mining, threatens wildlife across the globe and is the main reason for the rapid extinction of species we see today. Land-based wind power adds to this. Wind power, therefore, solves one problem by aggravating another. This has led to increasing popular resistance.

Offshore wind is limited to the continental shelves

Offshore winds, both fixed and floating, can only be used on shallow marine areas on the continental shelf. In addition, there must be a lot of wind. Suitable areas for offshore wind are therefore limited globally. In addition, there will often be conflicts with fishing interests. Negative environmental impact on birds and marine life can also be problematic in some areas.

Source: Improved Offshore Wind Resource Assessment in Global Climate Stabilization Scenarios, National Renewable Energy Laboratory, U.S. Department of Energy, Technical Report 2012.

Solar energy also needs space

Solar cells are also area-demanding. This is acceptable if they can be integrated into buildings, but more problematic where they displace forest or arable land. Besides, they produce energy only during the day. Solar cells combined with battery or grid connection are therefore suitable for decentralized energy production, but less suitable for centralized energy production in highly developed, densely populated areas.

A growing population needs more energy

1 billion 2 billion 3 billion 4 billion 5 billion 6 billion 7 billion 8 billion 9 billion 10 billion
1804 1930 1960 1974 1987 1999 2011 2023 2037 2057

    Source: https://www.worldometers.info/world-population

Replacing fossil fuels with renewable energy is a huge task. Solar and wind energy has limitations and cannot do the job alone. In addition, natural gas with carbon capture and storage will certainly be important in the future.

But will this be enough?

72% of Earth's surface is covered by the ocean

Tidal energy

Some places on earth have great tidal differences and currents. A number of companies have come a long way in developing solutions to harness this energy. But this still represents a small proportion of the energy mix in the regions concerned.

Wave energy

The west-wind belts in the northern and southern hemisphere cover vast areas. Persistent westerly winds over large stretches of sea lead to a wave climate with high energy content. Here, the energy density is greater than in any other kind of renewable energy. This is especially the case in the roaring forties of the South Sea.

Source: Encyclopedia Britannica, Inc. (https://www.britannica.com/science/Ferrel-cell)

The roaring forties


Wave heights November 27, 2019, southern spring, measured from satellites.
Source: https://earth.nullschool.net/

With wave heights of between 3 and 10 meters, year-round, and with its vast areas, the south-west wind belt is a formidable energy resource. So far, it has been ignored because the energy is considered impossible, or at least, too difficult, and therefore too expensive, to extract.

But is it possible? With today's robotic technology, it is easy to envision solutions that will work in practice. And unmanned operation will, paradoxically, simplify the operation and make it cheaper. And thus make away with the cost argument.

But this requires large investments that should rather go to this research, instead of maintaining a doomed fossil industry.

 

Home