Energia

Build Your Own
Micro-hydro Basics

Hydroelectric Generator

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ost machines that make electricity need some form of mechanical energy to get things started. Mechanical energy spins the generator to make the electricity. In the case of hydroelectricity, the mechanical energy comes from large volumes of falling water. For more than 100 years, the simplest way to produce the volumesof falling water needed to make electricity has been to build a dam. A dam stops the natural flow of a river, building up a deep reservoir behind it. However, large dams and reservoirs are not always appropriate, especially in the more ecologically sensitive areas of the planet. For making small amounts of electricity without building a dam, the small-scale hydroelectric generator is often thebest solution, especially where fast-flowing Canada and many other countries depend on large-scale hydro streams on steep developments for electricity. slopes are close by. A small-scale hydro system usually consists of an enclosed water wheel or turbine, which is made to spin by jets of highvelocity water. The water is taken from the stream and moved down slope to the turbine through a long pipecalled a penstock. Water flowing through the penstock picks up speed, and is directed at the blades of the turbine by nozzles. The turbine spins continuously, as long as there is water to drive it. The turbine is connected to an electrical generator, and the electricity is then available for running appliances or charging batteries. The spent water is returned to the stream. This kind of system iscalled

M

Micro-hydro systems can provide clean, environmentally friendly electricity in rural communities.

a “micro-hydro” system, “run-of-stream hydro” or “low-impact hydro.” In this activity, you will use plastic spoons to build a model of a simple micro-hydro system. It generates surprising amounts of electricity, provided you have a supply of pressurized water, such as from a lab sink.This model closely resembles real micro-hydro designs, and can produce enough electricity to light a small light bulb.

The completed micro-hydro turbine.

A Renewable Energy Project Kit

Another internet tool by: The Pembina Institute

Build Your Own

Hydroelectric Generator

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Making electricity We are surrounded by hundreds of appliances that use electricity to do work.But what is electricity? Basically, electricity is a flow of electrons in a metal wire, or some other conductor. Electrons are tiny particles found inside atoms, one of the basic building blocks of all matter. We call the flow of electrons through any conductor a “current of electricity.” Each electron carries a tiny negative charge. When electrons move through a conductor, they produce an invisiblefield of magnetic force, similar to that found around a magnet. The strength of that field depends on how many electrons are in motion. You can concentrate this field by winding the wire in which the electrons move into a tight coil with many turns. This causes many more electrons to be in motion in a small space, resulting in a stronger field. If you then place a piece of iron in the middle of thecoil, the electromagnetic field will turn the iron into a powerful magnet. While it is true that electrons moving through a conductor produce a magnetic field, the reverse is also true. You can make electrons move in a wire by “pushing” them with a moving magnet, which is how an electrical generator works. Electrical generators usually contain powerful magnets that rotate very close to dense coils ofinsulated wire. The coils develop a flow of electrons that becomes an electrical current when the generator is connected to an electric circuit. You will be building an electrical generator as part of this project. It uses moving magnets to create a current of electricity in coils of wire. This generator is technically called an alternator because the electrons move back and forth in the wire,...