Wind/Tidal/Wave Energy Flashcards
-Describe the types of material that are being used, or that are being considered for use, for the rotor blades on modern wind turbines.
- modern rotor blades are made from glass fibre reinforced plastics
- use of carbo fibre us being considered but it uneconomic for large turbines
- wood, wood-epoxy composites have not entered the market but are under development
- steel and aluminium alloys have problems with weight but are used for very small turbines
-Discuss the potential for generation of renewable energy in an urban environment.
-need to consider wind speed and surface roughness which increases in urban environment
- What are the societal and economic advantages and disadvantages of off-shore wind farms compared with onshore?
- maintenance is a bigger consideration for offshore
- higher capital costs for offshore but higher wind speeds and larger turbines can be used
-List the principal components (or parts) of a wind turbine system.
- The tower
- rotor blades
- rotor hub
- rotor bearings
- main shaft
- main frame
- gear box
- generator
- yaw system
- pitch systems
- power converter
- transformer
- brake system
-With the aid of annotated diagrams, describe the technical options for physically securing an offshore wind turbine in position.
- Mono pile
- gravity
- tripod
List the primary wind turbine types
- Savonius VAWT
- Modern HAWT
- Giromil/Darrieus VAWT
List FOUR different types of concept for wave energy devices
- Point absorber
- attenuator
- oscillating water column
- overtopping device
Briefly describe the operating principle of a “point absorber” wave energy device.
- device based on floater on the surface of the water which is held in place by cables connected to the seabed
- buoys use the rise and fall swells to drive hydraulic pumps and generate energy
- energy removed from the waves may also affect the shoreline, resulting in a recommendation that sites remain a considerable distance from the shore
Briefly describe the operating principle of a “surface attenuator” wave energy device.
- consists of multiple floating segments connected to one another and ae orientated perpendicular to incoming waves
- flexing motion is created by swells that drive hydraulic pumps to generate electricity
- similar environmental concerns to point absorber but more maintenance issues due to a more complex design
Briefly describe the operating principle of an “oscillating water column” wave energy device.
- can be located onshore or in deeper water
- onshore interference of waves may result in lower capacity factor
- device employs an air chamber integrated into the device, swells compress air in the chamber forcing air through an air turbine to create energy
Briefly describe the operating principle of an “overtopping device” wave energy device.
- use a long structure that takes advantage of wave velocity to fill a reservoir to a greater water level than surrounding sea
- potential energy is then captured in low head turbines
- can be used onshore or floating offshore
List the main challenges associated with power production using tidal energy systems
- Water is 800 times denser than air so stresses much higher
- operation in corrosive environment and occurrence of random impact events
- difficult to access
- grid installation requires expensive offshore subsea cables
