A mini water wheel generator is a machine for converting the energy of flowing or falling water into useful forms of power, often in a watermill. A water wheel consists of a wheel (usually constructed from wood or metal), with a number of blades or buckets arranged on the outside rim forming the driving car.
Water wheels were still in commercial use well into the 20th century but they are no longer in common use. Uses included milling flour in gristmills, grinding wood into pulp for papermaking, hammering wrought iron, machining, ore crushing and pounding fiber for use in the manufacture of cloth.
Some water wheels are fed by water from a mill pond, which is formed when a flowing stream is dammed. A channel for the water flowing to or from a water wheel is called a mill race. The race bringing water from the mill pond to the water wheel is a headrace; the one carrying water after it has left the wheel is commonly referred to as a tailrace.
In the mid to late 18th century John Smeaton’s scientific investigation of the water wheel led to significant increases in efficiency supplying much needed power for the Industrial Revolution.
How To Build a mini water wheel generator
Mainly a water wheel electric generator has two major components: the wheels and the dynamo. These components can be made both at home, but I recommend buying the dynamo because it’s not easy to make (not a very efficient one).
The largest wheel is the one which holds the water and the first to spin. When building the wheel you have to take into consideration the scale and the materials. For the overshot wheel the optimal diameter of the wheel is the largest possible (the drop) and the optimal rotational speed of is approximately: 21/ √D where D is the diameter of the wheel (meters).
You can build it from any material but the lighter, the better. Most water wheels are built from wood.
First we have to build the wooden wheels. You can do it by using the top and bottom of the barrel or you can build it from scratch. Here is a video tutorial (3 parts):
In order to produce more electric power you have to connect the wooden wheel to a smaller wheel thru a chain or by using a cogwheel in order to generate more rotations even if you lose some physical power over the rotation. Usually a dynamo doesn’t need much force to work optimal but rather a high rotation speed.
If you don’t want to use a dynamo to generate electricity you can use an electric DC motor. Most DC motors can operate as generators.
This video will better explain how to interconnect the wheels and maximize the output:
The pipe has to be as large as possible to minimize the friction and maximize the flow. The higher the drop and the larger the flow the more electricity your water wheel generator will produce. You may also take into consideration a capacity to store electricity and use it when in need. For example a solar energy storage battery will work just fine.
If you don’t need electricity you may adapt the water wheel to grind grain, to cut wood, strengthen iron or to sharpen tools. Anyway you choose to use it, a water wheel is an important installation when living off the grid or when SHTF.
If you still find it complicated building a water wheel electric generator by yourself, you may use a step by step guide with more specific measurements.
Another very efficient use of a water wheel electric generator is for aquaponic systems. If you already have an aquaponic system think about maximizing the outcome by producing free electricity to light a neon bulb (for example) to help plants grow even faster. Usually the water is pumped from the fish tank up to the plants. Where water is directed back to the fish tanks place a mini water wheel generator. If you are interested in building an aquaponic system you might find this video very helpful.