|
Components of a Wind Turbine:
The
main components of of a wind turbine are:
Components of a wind turbine
(source: United States Coast Guard : SFO Southwest Harbour)
Nacelle:
- The large head of the wind turbine (the outer
shell). Inside the Nacelle are the following:
Rotor:
- Fitted with 3 blades to catch the wind and make the rotor
turn.
Main
Shaft: - Connects the rotor to the Gear Box
Gear Box:- Connected to rotor by the
main shaft, Used to step up the rotating speed of the rotor. The
rotor rotates at about 20 rpm (where rpm = revolutions per minute).
This rotating speed is increased to 150 rpm (speed required
for the efficient functioning of the generator.
Generator:
- Uses electromagnets to induce electricity which is
transmitted through electrical cable to areas of need.
Radiator
- cools down the Generator.
Small
shaft - connects Gear Box to the
Generator
Controller:
- A computer that directs the different
components of the turbine
Yaw
Gear: - This gear is mounted on the tower and its a track
that enables the nacelle to turn to face into the wind in the event
that the wind changes direction.
Yaw
Motor:- This motor turns he nacelle so that the turbine
faces into the wind when the wind direction changes.
Brake:
- Stops the turbine when the wind is getting too
strong (i.e. > 25-26 m/s)
Anenometer:
- Measures the speed of wind and relate the information to
the controller which then stops the turbine.
Wind
Vane: - Measures the wind direction and passes on this
information on to the controller which then cause the turning of the
nacelle towards the new wind direction.
Sizes
of Wind Turbines
There are various sizes of wind
turbines for the different levels of needs: Large (over 300 Kilowatts
(KW)), Medium (30 to 300 KW) and small (below 30 KW) sizes. Large wind
turbines can be used to supplement national electricity supply by
combining the turbines to the national grid. Small scale uses like
supply to homes and farms can be met with smaller turbines either
connected to electricity grid or powered locally.
Is Wind Energy Renewable?
Wind energy is a
renewable resource. A renewable resource is a resource that is able to
be replaced or replenished, either by the earth's natural processes or
by human action within a lifespan. Wind energy is available at varying
proportions almost everywhere on earth. It cannot be depleted unlike
the conventional fossil fuel based energy resources.
Wind energy is a
“clean” energy resource, compared to fossil
fuels (coal, crude oil and natural gas). It does not emit
Green House Gases (GHGs) that are believed to be responsible for the
worsening global warming of our planet, Earth. It is believed that each
megawatt-hour (MWh) of electricity that is generated by wind energy
helps to reduce the 0.8 to 0.9 tonnes of greenhouse gas emissions that
are produced by coal or diesel fuel generation each year.
Setbacks
of Wind Power (Wind Turbines):
Wind
power has some setbacks. Some of these setbacks and their possible
mitigations are:
-
Obstruction
of human activities - Wind farm could obstruct human activities if
placed in low altitudes. The mitigation for this setback is to erect
turbines at high altitudes.
-
Obstruction
of Bird's path - Birds and other flying objects get killed if they fly
past a wind turbine farm; birds migratory path are altered in the long
run. This can possibly be mitigated by studying the pattern and path of
birds' migration prior to erecting a wind farm.
-
As
mentioned earlier, wind turbines can only operate effectively within a
certain range of wind speed usually between 3-4 metres/second
and 25-26 metres/s. The graph of power output by a wind turbine
relative to the speed of the wind is as shown below. A power system
that solely relies on wind will lack power when the wind isn't flowing
at all and when the speed is excessive. The mitigation for this is to
have energy storage (e.g. in batteries) during times of optimum wind
flow and put away for use during the periods of "too slow" and "too
fast" wind and/or have other sources of energy to compliment wind
during the down times.
Other Resources for Wind Energy:
Wind Power - Wikipedia, the free encyclopedia
Canadian Wind Energy Association (CanWEA)
Wind energy and other renewable energy information at Re-Energy.ca.
EIA Energy Kids - Wind
American Wind
Energy Association
Danish Wind
Industry Association
Energy Source: Wind Energy - Pembina Institute
Community
Wind Across America - Windustry |
