A BRIEF HISTORY OF ELECTRICITY
The first major use of electricity began in 1879, when Thomas Edison began installing incandescent lighting in notable locations like Wall Street in New York City. Edison wasn’t alone in his pursuit of electricity development, but he was the first to install integrated systems in conspicuous places.
At that time, Americans used various other light sources, like oil lamps, candles, and fires. A candle gives off only around a single watt’s worth of light. Calcium (or lime) lights could provide a lot of light, but it was a harsh light and reserved for conditions like the theater, hence the term in the limelight.
Most lighting was very poor – and often dangerous – in comparison to fluorescent bulbs, and electricity became popular quite quickly. By the turn of the century, other electric devices began to become available, and by the 1920s, Americans could purchase electric refrigerators, dishwashers, and washing machines.
The first electrical systems depended on extremely local power plants, within a few blocks, or even within the building. As time passed, electricity development became a regional responsibility, and today, the United States is split into many different systems of electricity distribution, including both regulated municipalities and for-profit utilities.
WHAT IS ELECTRICITY?
Electricity isn’t merely the existence of electrons but the flow, and it is their flow that provides power. It’s a little bit like gravity and the flow of water downhill. Water will move spontaneously downhill because of gravity. Electrons (like other charged particles) move spontaneously when they are in electric fields. An electric field is generated when there’s a difference in electric potential – called a voltage – just like a hill exists when there’s a difference in altitude.
Electricity is the flow of electrons, which themselves are small charged particles associated with atoms. Under neutral conditions, electrons stay with the atom or group of atoms that make up a compound. However, one electron is indistinguishable from another and can move from one atom to an adjacent one if the atoms make up a conducting material, like various metals.
Voltage can be thought of as the height of the hill. The bigger the voltage, the more electrons want to move, and the more power can be delivered.
Cataract Falls, Mount Tamalpais, California
Electrons moving can be diverted to do work, sort of in the same way that water traveling downhill can be diverted to run a mill or turbine.
The water’s kinetic energy is lost as it is used up in the turbine. Likewise, the electrons’ kinetic energy is lost when they are put to work in a device. The electrons don’t get destroyed in the process of losing energy, just as the water wouldn’t be destroyed.
When you plug in something like a light, electrons flow from the plug, through the light, and back out through the plug. However, it’s not that simple, since we use what’s called alternating current, or AC, which means that the electrons flow one direction and then reverse direction. Alternating current makes it easy to change from a high voltage to a lower voltage. This change is made through a transformer.
ELECTRICITY IN THE HOME
Today, inside the home, electricity powers computers, televisions, telephones, lights, refrigerators, heaters, air conditioning, healthcare-related devices, video games, rechargeable toys, stereos, alarm systems, garage doors, ovens, stovetops, dishwashers, clothes washers, routers, can openers, DVD players, DVRs, and countless rechargeable devices like phones and electronic tablets.
Computers, televisions, and handheld electronic devices have become increasingly popular, while refrigeration, heating, and cooling have become more efficient. These recent trends in home electricity use have shifted the greater part of home energy needs from climate control to electronics.
A FUTURE FOR TELEVISION?
Today, most households have more than two televisions, with 88 percent of homes have two or more televisions in 2009. The average household had 2.5 televisions. In the same year, 79 percent had DVD players, 43 percent had DVRs, and 86 percent of households had one or more computers. Nielson reported in May, 2011 that for the first time in 20 years, television ownership is slightly down, perhaps in part because computers may be replacing the use of televisions, DVDs, VCRs, and video games.
More about home energy in the energy efficiency section.