1800Houses were the main consumer of energy.

1850-1980 The use of energy per person is increased dramatically.

1979-1982Although the industry in U.S.A decreased its consumption by 20 percent, but the consumption of commercial sector and houses remained unchanged.

1950   Over 30 percent of houses used coal for heating and 22 percent used oil and 25 percent gas for the same purpose, but only 0.6 percent of houses used electricity for heating.

19788 percent of the houses used micro – wave ovens.

1990Use of personal computers are increased to 16 percent. In this period use of coal decreased to 0.2 percent, while use of fuel oil for heating increased to 11 percent.

1997In this year more than 80 percent of houses used microwaves and 30 percent electricity and 30 percent natural gas for the heating. 35 percent of households had personal computers.

85 percent of houses in U.S.A had a refrigerator and 15 percent had two or more.

Did you know?

The Federal Energy Administration invented a symbol namely an ant to show that how this little creature uses energy efficiently. This creature then became the trademark for U.S.A Department of Energy. The department then used ant costume, which was worn by an employee to give some information to students about the energy and science at school events.

Btu (British thermal unit) is a unit to measure the energy, which may be generated from different sources. One BTU is equal to an energy emitted from burning a wooden match.

What these things are made of,ink, pencil, bubble gum, dishwashing liquids, deodorant, eyeglasses, tires and heart valves. They are made from fossil fuels. They are called synthetic products.