MORE ABOUT ELECTRIC POWER: High Voltage

Remember how you had to blow on the peas to make them move through a straw? To move the peas through a short straw, it doesn't take much blowing. But what if you had a straw that went clear across your town or your state? That's pretty far. You are going to have to blow very hard.

The power company faces the same problem. It needs to create enough voltage to push the electric current all the way through the power lines to your home or school and back again. AC was invented so that power plants could produce current at high voltages, send it across long distances, and transform it to lower voltages when it reaches its destination.

The power plant produces alternating current at about 400,000 volts. Compared to the breath you push through a straw, 400,000 volts is like a hurricane.

When the transmission lines from the power plant reach your neighborhood, they go through a series of transformers that change the very high voltage electricity back into lower voltage electricity. In the United States, the voltage coming into a house is reduced to 220 volts for larger appliances, like stoves and clothes dryers, and 110 volts for lights, TVs and other smaller appliances. Some countries use 220 volts for all of their appliances and electric devices.

NEXT: Journey inside a photovoltaic system!