How can water make electricity?
This wonderful story begins with a great English scientist who lived in the last century He was Michael Faraday, born a poor boy and apprenticed to a book binder, At 22, he went to work in a laboratory and his scientific gifts were soon recognized Faradays work did much to help along the Age of Science, Andy loves him especially because every Christmas the great man took time to give a series of lectures on the wonders of science especially for children
As a young man, Faraday studied the simple electric cell in which chemicals were made to drive a current through a loop of popper wire He wanted to find a simpler way, a mechanical way to make this happen He found it with a magnet and a copper disk, A magnet is surrounded by invisible lines of magnetic force and so is an electric current Faraday knew of this relationship
He fixed the two ends of a hopper wire to his little dynamo and placed his copper disk where it could be rotated through the magnetic field surrounding the magnet and he cranked a handle to turn the disk It worked A current of electricity flowed through the copper wire circuit He had used the mechanical energy of turning the disk to make electricity and he knew at once that this mechanical work could be done by steam, by blowing winds or tumbling water
The great electric generators are bigger and better than Faraday s first dynamo • but they work on the same principle Electricity is generated in a wire circuit when coils of copper are rotated through a magnetic field or when the magnetic field is rotated around the copper The mechanical rotation is done by a round, spinning turbine And, as Faraday predicted, our turbines are made to work either by steam or by falling water
A turbine driven by water has a rim fitted with little buckets It is set where the water tumbles down into the buckets along one edge of the wheel This pushes the wheel around and around The wheel turns, a shaft and the shaft turns the moving parts of the generator, In place of Faraday’s copper disk, the modern generator has an armature, a massive wad of coils using maybe 30 miles of copper wire The magnetic field comes from an electromagnet, maybe two miles of copper wire wound around iron cores The wires of the electromagnet carry an electric current which, like a magnet, are surrounded by the invisible lines of force which make a magnetic field
The armature or the magnetic structure is rotated by the whirling turbine which may be turned by steam or wader tumbling over a dam or a natural waterfall The mechanical force of the water depends upon the amount or weight of the water and the height from which it falls The greater the wader power, the faster the turbine and the generator can be made to turn Some generators whirl around 3,600 times a minute
Electricity is induced, or generated, in the copper circuit as the lines of magnetic force are sliced from all directions The dolt which makes the electric current is called voltage and a big generator can produce 345,000 volts, or almost half a million kilowatts, This is enough electricity to supply about half a million homes,