Knowledge Base

Electricity 101 0

transmission-lines

This is a introduction to some of the fundamental concepts of electricity.

Think of electricity like water flowing through a pipe that’s pitched on a hill.  Gravity is the force that pushes the water down the pipe- this would be your voltage.  The amount of water that moves through the pipe would be your current, or amperage.

A volt is a unit that measures the force of electrical pressure that moves electrons.  An amp is measurement of the current flowing through a wire.

One amp of current moving with the force of one volt is equal to one Watt.  Naturally, multiplying the volts by the amps will give you your total power in Watts.

Volts (V) x Amps (A) = Watts (W)

We’re all familiar with Watts, as they’re used to rate household appliances.  One thousand Watts is equal to one kilowatt.

1000 Watts (W) = 1 kilowatt (kW)

When electricity is being used, we typically refer to it as “energy,” which is expressed is watt-hours (or kilowatt-hours).   A watt-hour is when an appliances draws electricity at a rate of one Watt for one hour.   Your electric bill will show you how many kWh your home uses.

Watt-hours (Wh) = Watts x Hours

1000 Watt-hours (Wh) = 1 kilowatt-hour (kWh)

Back to the actual flow of electrons- current.  There are a couple kinds of electrical current:  Direct Current (DC) and Alternative Current (AC).
 
Direct Current (DC) only moves in one direction, just like in that pipe metaphor we used earlier.  DC current is the kind of electricity that solar panels produce or the kind of electricity that’s stored in batteries.
Alternative Current (AC) is the kind of current that’s constantly moving back and forth.  This kind of electrical current is the same kind you use on a daily basis because it’s what the utility company provides.  Virtually all electronics you use are going to run on AC.  This is why a solar system usually requires a a solar inverter:  the DC electricity that comes out of your solar panels has to be turned into AC before you can use it to power all your lights, appliances, etc.

An electrical circuit is a “circular” path of electrons from a voltage source through a conductor (i.e. wire) to the load and then back again.

When this pathway is opened and continuity is broken, the electrons can’t flow through and in this example, the light will turn off.  When you flip the light switch, you’re opening an electrical circuit.  Kind of cool, huh?

More on circuits next time.

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Tom Jackson

www.gogreensolar.com

Original Article on Go Green Solar

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