Description of a Hydroelectric Turbine GeneratorBy: Billy DelGiorno

Introduction

Non-renewable resources, in today’s day and age, are the most common way of producing energy to be converted into a usable power source. Recently, however, clean energy production from natural, renewable resources such as wind, water, and the sun have been rapidly increasing due to the growing costs of non-renewable energy sources. An example of a renewable energy resource is a hydroelectric turbine generator. A hydroelectric turbine generator is a device that converts the mechanical energy of the moving water into usable electrical energy. This electrical energy can be used to power any standard object that runs off of electricity. This type of power generation is extremely cheap and environmentally friendly. For these reasons, hydroelectric power is desired for all applications.

The purpose of this product description is to inform prospective hydroelectric energy users the process of how this energy is created using a hydroelectric turbine generator. All readers, no matter their prior knowledge of energy generation, can read this description and all unfamiliar terms will be defined. There are two main parts to the turbine generator: the turbine, and the electric motor. See the figure below for a basic model of the turbine generator.

Exploded view of mini hydroelectric turbine generator

Electric MotorTurbine

Water flow in

Water flow out

The Turbine

Aforementioned, the turbine generator takes the energy of the water and translates it into electrical energy. The turbine comes into play by acting as a type of water wheel. The water flows into the generator (as shown above) and is caught by the “cups” that are located on every spindle of the turbine. The flowing water produces a force on each spindle causing the turbine to rotate around its central axis.

As you can see in the image to the right, the water is shot through a nozzle and hits each spindle of the turbine, causing rotation. Once the spindles holding the water rotate a certain distance, the water simply falls off and is expelled through a separate exit hole.

What is basically happening is the linear motion of the water is being translated to rotationalenergy of the turbine. There is a torque (a twisting force that causes rotation quantitatively found by multiplying the force of the water on the turbine and the radius of the turbine) developed around the central axis of the turbine. The central axis of the turbine has a rigidly attached shaft that goes through it. As you can see in the bottom picture on the right, this shaft is also connected to the electrical generator. This is also rigidly attached to the motor causing the inner workings of the motor to rotate at the same angular velocity (rotations per minute) and torque as the turbine.

The Electric Motor

The electric motor consists of three main parts: the internal magnets, the electromagnetic coil wire, and the battery. As you can see in the picture below, the shaft from the turbine is connected to the electromagnetic coil wire and passes through the motor.

Image of water hitting turbine spindleImage from

http://www.hydrogenappliances.com/hydro.html

Image of turbine-generator couplingImage from http://en.wikipedia.org/wiki/Water_turbine

What cannot physically be seen are the magnetic fields, which is the primary reason that the generator works. A magnetic field is a region around magnetic material within which a magnetic force acts. So in the picture above, the invisible magnetic field is traveling from the north magnet to the south magnet. Think about how standard magnets on your refrigerator work. The refrigerator is the south end and the magnet is the north end. The magnetic field is what draws these two ends together so that they stick.

Electromagnetic coils are basically electrical wire wrapped around a straight electrical wire. Electrons (a subatomic particle with a negative electrical charge found on atoms) travel through these wires creating a current. A current is basically a bunch of electrons traveling through a wire close to the speed of light.

Now an electrical motor can be used in two ways: to generate electricity (i.e. turbine) or produce rotational energy (i.e. electric fan). I will explain the latter of the two first because it will help to understand how the motor can produce electricity. So electric motor above is connected to the battery, which is the power source. This power source provides a current, which travels through the electromagnetic coils. A law called Ampere’s Law states that when a current is passed through a magnetic field (north magnet to south magnet) a magnetic force is developed which is perpendicular to both the magnetic field and the current. For instance, in the picture above, the magnetic field is moving from left to right and the current is flowing from outside the picture into the picture. This causes a magnetic force to point straight up in the air perpendicular to both components. This is the force that causes the rotation of the shaft. On the other hand, the current flowing through the right side of the electromagnetic coils is flowing from in the picture to out of the picture. This causes a magnetic force to point directly downwards and the shaft will the rotate that way. So now the coil is spinning counter clockwise all because a current is supplied from the battery.

Internal Magnet

Internal Magnet

Shaft

Battery

Electromagnetic coils

Now the electric motor generates electricity in the exact opposite way. This time there is no power source. The torque from the shaft, developed from the flowing water, spins these electromagnetic coils. When these coils are spinning in a magnetic field, it produces a current, which start flowing through the electromagnetic coils. This current then travels straight to the battery where it is stored for later use.

Conclusion

A quick simplification of the process is as follows:1. Water hits turbine spinning shaft2. Shaft spins coils in motor3. Spinning coils in magnetic field produce current through coils4. Current travels to battery and is stored

Although that may have sounded complicated, the principle of turbine-generator couplings is very simple. It is super efficient, safe for the environment, and can save plenty of money on electricity.