OCEAN ENERGY

Renewable Energies

• Solar

• Wind

• Hydropower

• Ocean

The Outlook

• Energy demand will continue to grow strongly;

• Alternatives to “Business as Usual” (BAU) can limit emissions to acceptable levels;

• Strong environmental policies will be required;

• Expanding the use of renewable;

• Alternatives to present sources will be challenging to implement at the needed scale.

Ocean Energy What is it?

• The oceans cover 75% of the world surface

• It is the largest renewable energy source available to contribute to the security of energy supply and reduce greenhouse gases emissions.

• Generation of electricity from the waves, the tides, the currents, the salinity gradient, and the thermal gradient.

Two types of categories: thermal energy from the sun's heat, and mechanical energy from the tides and waves.

• It is a predictable source of renewable energy with potential to satisfy (eg. meteorology).

Waves• First patent on wave energy conversion was issued early in 1799, and, already in 1909.

• Take advantage of wave’s energy (their movement) so the turbine could be put in action.

• Wave energy conversion is being investigated in a number of EU countries, major activity is also ongoing outside Europe, mainly in Canada, China, India, Japan, Russia, and the USA.

Wave energy systems

Shore line divices:• Easier installation and maintenance;• Not require long lengths of underwater electrical cable.

Offshore divices:• More powerfull wave regimes• Recent designs for offshore; devices concentrate on small, modular devices.

Tides• Exploit the natural rise and fall of the level principally by the interaction of the gravitational fields in the Earth-Sun-Moon system;

• Very similar to the technology used in traditional hydroelectric power plants.

Tidal range energy (the potential energy from the difference in height between high and low tides)

Tidal current energy (the horizontal movement, i.e. the kinetic energy of the water).

In PortugalPico Island (Azores)

Pelamis System (Aguçadoura)

Thermal Gradient• Due to solar heating, the top layer of the water is much warmer than deep ocean water;

• This difference has to be at least 3,5ºC so it could be an advantage for the thermal machine.

Advantages and Disadvantages

• In general all of them depends on the season, geographic location and weather condition;

• When the algae attatched on the system, it may produce methane and increases his concentration in the water;

• In case of thermal gradient energy, the cost of construction is low, has good efficiency (40-70 kW /m of wave) although the cost of inland transport is big.

• Ocean/tidal/wave resources are immense yet diffuse and expensive to exploit;

• Its an energy that have big potential to be more developed;

• In future this could represent another solution in renewables sources of energy so that the management in this area could be a more sustainable business.

Conclusions

References

•www.renewableenergyworld.com

•http://www.eu-oea.com/index.asp?sid=74

•Biomarine Nantes – St. Nazaire Business Convention (http://www.biomarine.org/index.php/component/content/article/3-newsflash/362-ocean-energy)

Thanks for your attention!

Authors:

Pedro Ribeiro

Dimitra Poumplaki

Maciej Cichocki

Evangelia Androna

Kiriakos Tsilavis

Silvia Infante González