Wave Power

A Developing Solution

Basic Premise

• The transport of energy by ocean surface waves, and the capturing of that energy to do useful work

• Industrial and small scale technologies are being developed to best capture and convert that kinetic energy into electrical energy.

• COMPLETELY CARBON FREE

Sources of Power

• Wave Power is determined by the following factors– Wave Height• In turn determined by fetch, duration of wind, wind

speed, and water depth

– Wave Speed (the faster the better)– Wavelength (the longer the better)– Water Density (the denser the better)

Types of Device

• Wave power devices come in two traditional forms: surface or submerged.

• ‘Surface’ includes floating or shoreline applications.

• ‘Submerged’ refers to devices anchored on the sea bed, most likely a permanent fixture.

Existing Technologies

• Pelamis Wave Power- Long, cylindrical, semi-submerged sections connected by hinged joints. As waves pass under the sections, they move independently, and that movement is resisted by hydraulic cylinders. These cylinders pump oil through motors, which in turn drive electric generators. All power is fed to one cable located on the sea bed.

• Here is a diagram

Existing Technologies

• Wave Dragon- a floating, slack-moored energy converter that utilizes ‘overtopping’ methods of energy generation. Waves are focused by large “arms” that propel the water onto a large platform. The water then returns to the ocean via gravity, passing through hydroelectric generators.

Basic Schematic

Developing Technologies

• CETO- Submerged buoys move up and down due to ocean (wave generated) swell. The buoys pressure seawater, and send it ashore to drive hydroelectric generators.

• Will finish development in 2009.

Basic Schematic

Compared/Contrasted

• Pelamis- 750 kW of electricity, faces into waves so bears minimal damage.

• Wave Dragon- 4 to 11 MW, only one moving part (turbines).

• CETO- 100 kW of electricity, totally submerged for aesthetic benefits/protection from damage.

• NOTE– 1kW is roughly equivalent to 1 house.

Possible Problems

• Inconsistency of waves• Devices have to withstand constant punishment

from the waves themselves• Noise/ aesthetically unappealing• Site dependent, not every bit of ocean has

suitable waves• Rarely, diminishment of waves (ecological/surfing

detriments) due to obstruction• Only for coastal areas

Sources

• Wikipedia• http://www.rise.org.au/info/Tech/wave/index.

html• For more ideas/technologies, visit the above

site.

Discussion

• Is it worth devoting time, effort, and (limited) money into a program that might only benefit coastal areas/ countries?

• Are the given aesthetic detriments worth the completely carbon-free source of power?

• In your opinion, how does this technology stack up against more household ideas like solar or wind energy?

• Which do you prefer, submerged or surface wave power technologies?

Discussion Contd.

• Should the federal government require tax money from areas that would not benefit from wave power for programs that would only benefit coastal areas? Also, should green energy (and especially wave power) be approached at a state or federal level?