The Mysteries of Life with Tim and Moby:
Wind Energy
That’s a good question! First, some history…
It may seem strange to think of wind as a source of energy, but we’ve been harnessing it for thousands of years. In ancient Egypt, people used wind to power their sailboats along the Nile river. The first windmills were used in Persia - in today’s middle east region - about 1,500 years ago. Primitive windmills looked sort of like egg beaters and they were mainly used for grinding grain and drawing water from wells. Later, people from Western Europe improved on the technology by making propeller-style blades out of sails.
Ancient EgyptPersiaWestern Europe
Today, modern wind turbines are strong, sleek, and well-suited for converting the force of wind into energy.
- - Beep?
Well, the rotor blades are aerodynamically shaped to make them really efficient. The blades convert the wind’s energy into a rotational energy called “torque”.
How much torque is produced depends on three things:
1. Air density,
2. Wind Speed,
3. Length of the Rotor Blades
As each of these factors increases, so does the amountof power produced.
When strong winds blow against a turbine, the force causes the rotors to turn pretty quickly.
Inside the turbine, a generator converts the movement into electricity.
That electricity can be sent through power lines to light up your house! - - Beep?
Actually, there are lots of places where you can see wind turbines at work, but one of the most dramatic is called a wind farm.
- - Beep!
No, they don’t grow wind in a wind farm, but it’s a place where electricity is made from wind.
Wind farm typically have at least a couple dozen
turbines that are positioned to take advantage of
local wind patterns.
- - Beep!
Good point! Many people think it’s a good idea to invest in renewable energy sources like wind, which is clean, and relatively cheap to generate.
A renewable energy source is a source of energy that for all practical purposes never runs out - like wind or solar energy. That’s in contrast to fossil fuels like coal and oil, which the earth only has finite amounts of.
Right now, only about 1% of all the power we use is America is created by wind. Even so, the United States is the second-highest producer of wind energy in the world. And since North America has more sites suitable for wind farms than any other continent, our wind power output should have no problem growing!
- - Beep?
Yeah, there are a few drawbacks to getting electricity from wind. For one thing, some people think turbines are ugly, and they don’t want to look at them all day. Other people worry that wind turbines are dangerous to flying animals, like birds and bats. Some studies suggest that the numbers of animals hurt by wind turbines is fairly small. But it is a real problem that the wind energy industry is looking into.
-- Beep!!
Nah, it’s windy out here, but it’s not that . . . windy. . .
Wind Power Vocabulary Terms: These are the parts of a Wind Turbine
1. Rotor blades (Turbine) - capture wind's energy and convert it to rotational energy.
2. Hub (outside cover) and 4. Rotor hub (inside) - this is the center of the actual turbine, where the wind shaft and turbine are connected
3. Nacelle -The structure that holds the gearbox and generator, plus the brakes for the system
5. and 8. Brakes - these will keep the speed of rotation within safe limits so the equipment isn’t damaged.
6. Low Speed (“wind”) shaft - connects the turbine and gearbox
7. Gearbox -increases the speed of the wind shaft to make the generator turn faster.
9. High Speed (“generator”) shaft - connects the gearbox and generator
10. Generator - Generates electricity using copper wires and magnets.
11.Tower - supports the turbine and nacelle and lifts entire setup to higher a elevation so the blades can safely spin
12. Transformer: Inside the transformer, the electricity from the turbine is converted to a voltage that we can use for power.
Gear Ratios:
In order to make wind power useful, we use gears. One gear is attached to the TURBINE and so it rotates at WIND SPEED. The other gear is attached to the GENERATOR. It will be smaller than the TURBINE GEAR, so it will be rotating FASTER!
Calculate the speeds for these gear sets…
Ratio = 1:2(Every time A rotates1 time, B rotates2 times) / 1) Example: If Gear A is rotating at 10 miles an hour,
Gear B =10 mphx 2 = 20mph
2) If Gear A is rotating at 18 miles an hour,
Gear B = x =
3)If GEAR B is rotating at 50 miles an hour,
Gear A =÷ =
Ratio = 1:1.5
(Every time A rotates1 time, B rotates1.5 times) / 1) Example: If Gear A is rotating at 10 miles an hour,
Gear B =10 mphx 1.5 = 15 mph
2) If Gear A is rotating at 24 miles an hour,
Gear B = x =
3)If GEAR B is rotating at 75 miles an hour,
Gear A =÷ =
Ratio = 1:5
(Every time A rotates1 time, B rotates 5 times) / 1) Example: If Gear A is rotating at 10 miles an hour,
Gear B = 10 mph x 5 = 50 mph
2) If Gear A is rotating at 45 miles an hour,
Gear B =x =
3)If GEAR B is rotating at 85 miles an hour,
Gear A =÷ =