Wind Energy Flashcards
(21 cards)
What is the (1) minimum speed required to rotate most wind turbines, and (2) the maximum cut-out speed?
8 kph, 90 kph
What wind speed range does a typical turbine generate maximum power?
36 kph to 54 kph
What are the two common complaints from local people when wind turbines are installed?
Visual impact, noise
Wind is an intermittent power source. Why is this an issue?
The grid has little storage capacity, so if the wind drops there could be a blackout.
How does the law of large numbers apply to wind power generation?
The aggregate power generation of all the power stations will be less volatile than the power generation of a single station.
Why is a pitch system an important component of a wind turbine?
Controls rotor speed, preventing them from turning at too high or low speeds to generate electricity.
What does a gear box do in a wind turbine?
Connects the low speed shaft to the high speed shaft
(1) What rpm does a low speed shaft run at? (2) What rpm does a high speed shaft run at?
(1) 30-60 rpm, (2) 1000-1800 rpm
What does the generator do in a wind turbine?
Produces 60-cycle AC electricity
What is the role of a yaw drive in an upwind turbine?
Orients upwind turbines towards the direction of the wind.
Offshore wind speeds tend to be slightly faster than on land. (1) Explain why this is, and (2) Why is this such a big issue for power generation?
(1) Less low-altitude wind disruption. (2) Small increases in wind speed corresponds to large increases in power generation.
List 4 cons of wind power generation.
Any 4 of: noise, visual impact, electromagnetic interference, lower property values, high installation costs, can kill birds
How does the NIMBY phenomenon apply to wind turbines?
People support wind power generation but don’t like local wind turbines.
In a wind turbine, why does the pitch system prevent the rotors from spinning at low wind speeds?
Insufficient power generation at low speeds,, so the rotors spinning causes pointless wear to the wind turbine
In what environment does a wind turbine need to be placed for maximum power generation?
Usually in rural areas with a naturally high amount of wind, with no obstacles nearby (e.g. houses, hills, forests)
Why do wind farms tend to be placed in rural areas? (Give two reasons)
Fewer obstacles to wind flow, less residents to complain about visual/noise impact
Why are taller wind turbines attractive?
They are more likely to access higher speed winds
What is the basic physical principal behind an electric generator?
Copper coils move relative to stationary magnets and induce a potential difference
The O-wind turbine design is particularly innovative because …
It ensures the shaft spins at a constant rate regardless of wind direction.
Managing the use, development and protection of natural and physical resources in a way, or at a rate which enables people and communities to provide for their social, economic, and cultural well-being and for their health and safety is handled in New Zealand by the ______ ________ ___.
Resource Management Act
How often does the price of electricity change in New Zealand’s wholesale market?
Every 30 mins