CHEE2695 – Lecture 12
Wind energy:
- Wind energy produces energy from wind.
- It is modular and can range from just a few turbines to a whole wind farm.
- Offshore wind farms are quite common in shallow areas.
- Wind energy accounted for around 5.8% of total electricity generation, and
34% of renewable generation in Australia.
- Wind energy is a political issue. Policy decisions and economic factors are the
driving forces of wind farm production.
Types of wind turbines:
- Type 1: aerodynamic drag.
o This is the simplest form of turbine. The velocity of the device cannot
exceed wind velocity.
- Type 2: ‘lifting’ wind turbines.
o These rely on Bernoulli principal lift and are preferred for modern
devices.
- Type 2a: vertical axis lifting turbines.
o These are good for small installations.
- Type 2b: horizontal axis lifting turbines.
o These are very common and have 2 or 3 rotor blades.
Wind power:
- Power output is given by:
1 3
P= ρA V
2
- It is very sensitive to wind velocity.
- Typically, wind velocity is larger at higher altitudes.
- Modern wind turbines are typically around 80 m high.
Gearbox and variable speed:
- The maximum efficiency of a wind turbine is 59.26%, according to the Betz
law.
- Gearboxes introduce more efficiency losses. Larger turbines will often require
gearboxes.
Wind energy:
- Wind energy produces energy from wind.
- It is modular and can range from just a few turbines to a whole wind farm.
- Offshore wind farms are quite common in shallow areas.
- Wind energy accounted for around 5.8% of total electricity generation, and
34% of renewable generation in Australia.
- Wind energy is a political issue. Policy decisions and economic factors are the
driving forces of wind farm production.
Types of wind turbines:
- Type 1: aerodynamic drag.
o This is the simplest form of turbine. The velocity of the device cannot
exceed wind velocity.
- Type 2: ‘lifting’ wind turbines.
o These rely on Bernoulli principal lift and are preferred for modern
devices.
- Type 2a: vertical axis lifting turbines.
o These are good for small installations.
- Type 2b: horizontal axis lifting turbines.
o These are very common and have 2 or 3 rotor blades.
Wind power:
- Power output is given by:
1 3
P= ρA V
2
- It is very sensitive to wind velocity.
- Typically, wind velocity is larger at higher altitudes.
- Modern wind turbines are typically around 80 m high.
Gearbox and variable speed:
- The maximum efficiency of a wind turbine is 59.26%, according to the Betz
law.
- Gearboxes introduce more efficiency losses. Larger turbines will often require
gearboxes.
