Anemometer - Wind vane

Theoretical foundations of wind energy:

Taking advantage of the wind to generate energy is as old as civilization, but in recent years it has been growing the fastest in the world. Wind farms begin to proliferate in every corner.

It has been used for more than 2,500 years: navigation sails, grain mills or water pumping, but it began to be used to produce electricity in the 20th century.

Wind turbines have evolved in a few years from a power of 25 kW to 1500 kW and their power is progressively increased.

The wind turbine is the machine used to convert the force of the wind into electricity carrying an electronic orientation mechanism that monitors the direction of the wind by means of a vane.

The anemometer and the vane are used to measure the speed and direction of the wind and connect or stop the wind turbine depending on it, turning and orienting it depending on its direction.

Hence, the need for students to know and appreciate its usefulness, both for this objective and for the same meteorology and daily use.

Didactic objective:

Build an anemometer-vane that allows us to verify its main functions and characteristics, as well as its direct applicability in the generation of wind electric power.
Material:

• Wood veneer 15 x 15 cm.
• 1x2x30cm wooden strip.
• A knitting needle.
• 20 x 20 cm square wooden base.
• Wooden ball approximately 1.5 cm in diameter.
• Ping pong ball.
• Wire.
• Cardboard discs.
• Thread.
• Screws, nuts and washers.

Process:

First:

• Cut the 15 x 15 cm sheet making an arc with a compass, the vertex of the square being the center of the arc.
• Poke two holes at each end of the bow, near the edge.
• Insert into each hole, and in this order: a screw about 2 cm long, two washers suitable for the screw and then two nuts.
• Fasten all of this to the wood veneer with a new nut.
• Link the wire from one screw to another, following the arc of the wood so that it can later be the guide for the anemometer pendulum.

Second:

• Attach the ping pong ball to a string with strong glue.
• Pass the thread between the guide wire and the sheet, tying it to the upper corner of the table.

Third:

• In the 30cm strip, and on its 2cm wide face, make two holes 1cm apart between them and from the edge.
• Make the same holes and making them coincide in the guide plate so that they coincide with those of the strip.
• Screw the slat to the sheet.
• Also make a hole in the strip, on its side 1 cm wide and about 8 cm from the end.
• Insert the knitting needle through this hole, it will be the axis.
• Fit in the axis, a washer and the wooden ball to act as a bearing.
• Place another washer and an insulating tape stopper so that it causes as little friction as possible.

Fourth:

• Place the cardboard with a drawing of the wind rose.
• Fit the axis in the base
• Glue on the 20x20cm wooden base, the wooden block in the center. Make a hole in the block where the shaft (needle) fits, filling it with glue.

Fifth:

• Place a counterweight (Stone for example) at the free end of the batten to balance the vane.

To correctly orient the device, we will use a compass.

To graduate the anemometer we could do it, going in a car on a windy day in a place without circulation.

Hold the anemometer out of the window and with the car running at 5 km/h make a mark on the cardboard. Repeat the operation with speeds of 10, 15, 20 and 25 km/h.