3 Amazing Ways to Harvest Clean Energy From Oceans

As the climate change problem comes more and more to the forefront of public consciousness, politicians and scientists are increasingly looking to renewable energy as the solution. The big three in terms of green energy are wind, solar and water power. Although, due to the difficulties involved, the latter has not been developed nearly as much on a large-scale format as the others.

However, the ocean as a source of clean, renewable energy has incredible potential. Let’s not forget that more than two-thirds of the world’s surface is covered by water, and that it is a constant and consistent form of energy with no pollutants or adverse effects from its harvesting.

The energy from the ocean can be harvested in three ways:

• Wave Power
• Tidal Power
• Thermal Power

If we can put in place large-scale and long-term facilities for harvesting the energy from these three, we can begin to wave goodbye to our chronic energy crisis.

1) Wave Power

Wave energy depends on the relationship between the water and the wind; i.e. the power found on top of the waves. If you’ve ever tried your hand at surfing, body-surfing or even just swimming in the ocean, you’ll be well aware of the power in those waves.

There are several ways of harnessing this power, though the most common is a stationary piston-based system. The up-down motion of the water operates the piston, which powers a generator. There are also buoyant devices which have motion-operated generators – the same motion of the waves pushes these buoys up and down and activates the generator. Alternatively, another device uses an empty chamber filled with air. The waves rushing in push the air out, which is forced through a turbine.

Just last year, a British company named Sea Wave Energy Ltd made significant advances in the field, which can be read more about in this article: New Wave Energy Device Delivers Breakthrough Results in Terms of High Efficiency and Low Cost.

2) Tidal Power

In contrast to wave power, tidal energy relies on the relationship between the ocean and the moon, not the wind. The relentless and eternal fluctuations of the tide can be harnessed in the form of tidal fences, tidal turbines or tidal barrages. Though these all work in different ways, they achieve the same end - using the kinetic energy in the waves to operate a turbine or electromechanical generator.

Late last year, developers in Swansea, Wales, announced plans for the world’s first tidal lagoon, which will produce 240mega-watts of clean, renewable energy and will be sufficient to power the entire city. This story, Specialist Planning Advice Offered to World's First Tidal Lagoon Scheme, discusses this exciting new opportunity in more detail.

3) Thermal Power

Formally known as ocean thermal energy conversion (OTEC), this method differs from the previous two by focusing on the heat in waves, rather than their motion. With the sun beating down on the ocean all day, every day, it unsurprisingly retains a lot of energy.

Although the temperature of this water is far from boiling, it can be used to bring substances like ammonia, which have a low boiling point, to vaporisation. Alternatively, it can be introduced into a low-pressure environment, which causes it to boil more quickly. Either way, the vaporised liquid turns into steam, which can be used to power a turbine.