Build this Unidirectional Wind Turbine: Wells Turbine

In this article I will explain you the full step by step building guide for making one Wells turbine at home, which is intended specially for homemade sea wave electricity system using oscillating air column.

What is Wells Turbine

So first we must understand that wells turbine is a special type of turbine in which the blades are shaped in such a way that they rotate in one fixed direction even when air is flowing from both sides like from front or from back.

That is why this turbine is perfect for sea wave systems where the air is moving up and down continuously inside the air column.

So this turbine can keep rotating in one direction and drive one alternator motor without reversing again and again.

How this Wells Turbine System Works

In the above image we can clearly see that everything is placed inside one long vertical type pipe and that pipe is called pipe enclosure with air column.

This pipe is filled with air and it is placed vertically over the sea water level, just like in the previous wave energy diagram.

How air flow is created

When sea wave rises and falls, that water level inside the lower side of the pipe also goes up and down. So it pushes the air upward when wave rises and pulls the air downward when wave goes down.

That creates oscillating up/down air flow and in the diagram we can see that with blue arrows both at top and bottom of the pipe enclosure.

How air flows through the turbine

Now we can see that the air is moving up and down but there is one turbine placed in the middle portion of the pipe.

That turbine is having one round center part called hub, and from that hub many curved blades are fixed in all directions, forming the wells turbine.

All these blades are shaped like twisted wings, and all are tilted in same direction with respect to airflow.

These blades are made in such way that when air hits them from any side, they will rotate the hub in one same direction only. That magic is happening because of the airfoil shape and blade angle.

How Turbine Rotates

So when air is coming from bottom side (due to wave push), it passes through these blades and creates lift force on them.

This makes the turbine spin in one direction. Then, when wave goes down and air starts coming from upper side (reverse), again it hits the blade in such angle that it still rotates the hub in same direction.

That is the special thing of wells turbine.

We can also see in the diagram how rotation direction is fixed with red arrow even when air is flowing from both sides.

Connection with Alternator

Now on top of the hub we can see one vertical shaft going up and connected to one alternator.

That alternator is nothing but a dc motor or generator which produces electricity when its shaft rotates. Since the wells turbine keeps spinning in same direction, the alternator also keeps generating voltage smoothly.

Why this System is Good

This system is perfect for sea wave electricity because it does not need any electronic circuit to reverse anything.

Even though air is changing direction, the turbine does not change direction. So we can connect alternator directly, and take output using normal wires.

Also there is no need of rectifier in between if we want ac output. But if we want dc output then we can still put a bridge rectifier.

Some Important things to Note

Now we must remember that this kind of turbine works only when the blades are made with correct angle and shape.

If we just put flat fan blades then it will rotate one time in one direction and next time in opposite direction, and that will not generate useful electricity.

So blade shaping is very important. Also the alternator must be low rpm type so that it can generate voltage even with slow turbine rotation due to air flow.

Step by Step Construction of Wells Turbine System

Step 1 – Collect all required materials

First we have to collect all the needed parts. We need one vertical pipe or cylinder for making the pipe enclosure with air column.

We can use pvc pipe of around 6 inch to 8 inch diameter and 2 to 3 feet long. Then we need one hub disc for fixing the blades, it can be round plastic or plywood disc around 6 inch diameter.

Then we need 6 to 8 blades made from plastic or aluminum sheet, each maybe around 5 inch long and 1.5 inch wide.

We also need one shaft rod around 10 mm thick to pass through the hub. Then we need two circular end supports for the pipe. And finally one small dc motor or alternator which will be fixed on top.

Step 2 – Build the blade disc

Now we take the round hub disc and we mark equal positions around the edge where blades will be fixed. So if we are using 6 blades, we mark 6 positions at 60 degree gap.

Then we drill small slots or holes at those positions. Now we take the blade pieces and bend them slightly in curved shape, like airplane wing.

Then we fix these blades into the slots of the hub disc at around 35 degree angle with respect to the tangent. All blades must be tilted in same direction. We can use super glue and small screws to hold them tightly.

Step 3 – Fix shaft to the hub

Then we drill the center of the hub and insert one strong straight metal rod through it.

This rod becomes our main shaft. We must keep the blade disc exactly at the center and balance it properly so that it can spin smoothly. We can lock the hub to the shaft using epoxy or nut bolt.

Step 4 – Prepare the pipe enclosure

Now we take the vertical pipe which is our air column enclosure. We cut two round discs same size as the pipe, one for bottom and one for top.

These discs can be made from plywood or acrylic sheet. We make one hole at the center of each disc so that the shaft can pass through it. We also drill small holes around the edge of the discs so we can screw them tightly on both ends of the pipe.

Step 5 – Insert turbine inside pipe

Now we pass the turbine shaft through the pipe vertically from bottom to top, and we fix the two support discs at the ends of the pipe.

The shaft must pass through center holes of both discs and we must use ball bearings or plastic bushings at both ends so that shaft can rotate freely. Now the turbine is inside the pipe and it can spin when air flows.

Step 6 – Mount alternator on top

Now we fix the small alternator or dc motor on the top disc. The shaft of the alternator must be aligned with the turbine shaft.

We can couple the turbine shaft and alternator shaft using rubber pipe or flexible tube. So now when turbine rotates, the alternator also rotates.

Step 7 – Seal and support everything

Now we seal the pipe joints, screw all parts tightly and mount the whole unit on one base or frame. We must make sure that the air can enter from bottom and exit from top without leakage and the turbine is spinning freely.

Step 8 – Install in wave column or test setup

Now we place this full unit on top of sea water wave pipe column, where air is moving up and down due to sea wave action.

Or if we want to test at home, we can use a small fan or piston at bottom to push and pull air artificially to simulate the wave effect.

Step 9 – Connect output wires

Now we take two wires from the alternator output and connect it to a bridge rectifier if we want dc or directly to ac load like small led if we want AC. We can also connect capacitor and battery if needed.

Step 10 – Test and observe

Finally we push air from bottom and pull it from top alternately and observe the turbine rotation. It must rotate always only in one direction even though air is changing direction, right.

That will show the wells turbine is working. We can check the voltage at output wires using multimeter.

Final thoughts

So by seeing the image we understood very clearly how wells turbine is installed inside pipe with air column, how the sea wave creates oscillating air pressure, how the blades are rotated in one single direction, and how alternator is connected at top to generate power.

So this is very smart and clean method for using natural sea wave power to make electricity without touching water or using big moving parts.

After this, by following the full step by step method, we can build one complete working wells turbine unit just like shown in the diagram. It can be placed on top of sea wave column pipe and used to generate electricity using only air flow created by ocean waves. This method is simple, diy friendly, and useful for understanding real renewable energy.

Video Showing the Real Prototype Working of a Wells Turbine