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Electricity 101

The basics of how we make electricity and send it your way.

Electricity 101
Electricity is fundamental to a whole lot of things that we do at home and at work. Despite its importance, it is something we rarely think about. It is certainly something we never see, hear or smell. Few of us can adequately define exactly what it is. So, that's exactly what we'll do here:

Electricity is the flow of small particles known as electrons. The transmission of those electrons releases energy.

Electrons are found in atoms. Atoms are the smallest part of an element that cannot be broken down by chemical means. Electrons in the atoms of metal, such as copper and aluminum, are easily moved along a wire.

How we make the electricity that turns the lights on
It seems so simple. At that level, it is. But when it comes to creating that electricity and transmitting it to you cleanly and efficiently, things start to get a lot more complicated. We'll keep from getting ahead of ourselves, though, and start right at the beginning.

The production of electricity is called generation. Generation facilities, better known as power plants, are the first step in providing electricity to customers. Using some form of energy to turn a turbine, like the sun, moving water, or burning fuel, creates electricity. Water provides one of the simplest examples. At a hydroelectric site, water typically falls downhill through a large tube, called a penstock. The force of the water, which increases with height, spins a turbine at the bottom of the tube, which moves electrons along a wire. The flow of electrons along the wire makes an electric current. This current is what powers our lives.

Power producers measure the output generation in kilowatts or megawatts. One kilowatt is equal to 1,000 watts – enough energy to light 10, 100-watt light bulbs (or 50 energy-efficient 20-watt bulbs). One megawatt is equal to 1,000 kilowatts. Typically, one megawatt is enough energy to meet the instantaneous demand of about 1,000 Vermont homes.

The electricity generated by a power plant is sold in units called kilowatt-hours or megawatt-hours. A kilowatt-hour is the unit of electricity consumed if your demand is consistently one kilowatt over the course of an hour. If you used 10, 100-watt light bulbs for one hour, you would use one kilowatt-hour of electricity.

How we get that electricity to your light bulbs
Different kinds of power cables transport electricity from the power plant to your home or business. High-voltage electricity is moved through transmission lines, which carry the current over long distances from the power plant to the substation. Large transformers at substations reduce, or step down, the intensity of the electricity so that it can be moved safely along to the smaller distribution system.

The distribution lines that make up the system are the wires you see running pole-to-pole along the street. These lines are also the ones that run from the pole to your home, connecting you to the grid and delivering your electricity. This distribution system is made up of three-phase (or three-wire) line and single-phase (or one-wire) line. Three-phase lines are generally used for large commercial customers. Single-phase lines serve residential customers.

Just before the current reaches your home, a distribution transformer steps down the voltage of the electricity again. This transformer can usually be found on the pole outside of your house or in your neighborhood. From this transformer, power travels down the line, through your meter and into your home's network of electrical wires and outlets, powering everything from your refrigerator to your TV.

Probably the most impressive thing about all of this is that it happens in an instant. At almost the exact moment you're turning on the light, we're generating the electricity to power the bulb.

If you were a CVPS customer before the merger and want to learn more about how we transmit power to your home, click here. Legacy GMP customers can click here.