Marine renewable energy Flashcards
What are the main categories of marine or ocean renewable energies?
- Wave Energy
- Tidal Energy (Tidal Range vs Tidal Stream)
- Offshore Wind Energy
- Ocean Thermal Energy
Why are marine renewables successful?
Reduction of their Levelised Cost of Energy
Which renewable energy source has high technological maturity and market potential with low innovation risk?
Tidal Energy
Which renewable energy technology has low technological maturity and market potential, requiring significant innovation effort?
Ocean Thermal Energy Conversion (OTEC)
What types of energy can be extracted from waves?
- Kinetic
- Potential
- Mechanical
- Electrical
- Thermal
What is the primary source of ocean wave energy?
Ocean waves are a concentrated form of solar energy
Which two factors determine the characteristics of ocean waves?
The fetch and the duration of wind action
What is “fetch” in the context of wave energy?
Fetch is the distance over water that the wind blows in a single direction
What is typical value of wave power for deep water?
6 – 70kW/m
What is the minimum wave energy flux required for economical wave energy extraction?
20-25 kW/m is required for it to be economically viable
Whats is the gross potential of wave energy?
18500 TWh/year
What is the technical potential of wave energy?
2000 TWh/year
What is a wave energy converter?
A device that absorbs part of the ambient incident wave energy
How does a WEC transform mech energy to electricity?
A mechanical system commonly called Power Take-Off
How is wave energy absorption described in terms of wave interaction?
It’s a wave interference process where waves generated by the motion of the WEC cancel out incident waves
What design consideration is crucial in civil engineering to prevent structural failures like the Tacoma Narrows bridge collapse?
Avoiding a match between the natural frequency of the structure and the frequency of external loads
How is wave energy absorption maximized in wave energy converters (WECs)?
When the WEC operates at resonance with the waves
Has technological convergence been observed in wave energy converters?
No
What are the three common criteria for classifying wave energy converter (WEC) technologies?
- The working principle
- The dimension/configuration
- The location (offshore, nearshore, shoreline)
What are the three main categories of WECs based on their working principle?
- Oscillating water columns
- Oscillating bodies
- Overtopping devices
What is an example of a floating oscillating water column?
Buoy
What are the two categories in oscillating bodies?
- Heaving wave energy converters
- Pitching wave energy converters
Examples of pitching wave energy converters (submerged)?
Wave Roller
What are the two categories in oscillating Water Column?
- Fixed - Isolated/Breakwater
- Floating
