FREE ESSAY ON ENERGY

ENERGY

Energy is the ability to do work. The two different types of energy are kinetic and
potential. Kinetic energy is energy in motion and potential energy is energy that is
stored. Energy is measured in units which are BTU (British thermal unit) and a joule. The
Law of Conservation of Energy states that energy can't be created or destroyed, but it
can be changed in form. Heat is a form of energy that comes in different forms such as
conduction, convection, and radiation. Conduction is when energy is passed directly from
one item to another. Metals are excellent conductors of energy. Plastics or other
materials aren't. These are called insulators. Convection is the movement of gases or
liquids from a cooler spot to a warmer spot. Radiation is the final form of movement of
heat energy.
Electricity is the flow of energy from one place to another. Atoms have electrons
circling them. Some are loosely attached. When electrons move among the atoms of matter,
a current of electricity is created. Electricity flows through some objects better than
others. Copper is a good conductor of electricity. The electric force that pushes
electrons is measured in volts. Batteries store chemical energy. An electric circuit
connects the positive and negative poles of the battery and allows an electrical current
to happen. Static electricity doesn't move. It is the energy that can stick a balloon to
a wall if you rub the balloon across a sweater. Lightning is another form of static
electricity.
Fuels are used to heat water in a boiler to make steam. That steam turns a turbine. The
spinning shaft of the turbine drives the generator. Many types of fuels are used in the
boiler to heat the water. When a wire or any electrically conductive material moves
across a magnetic field an electric current is produced in that wire.
The inside of the earth has a core, a hot liquid mantle, and a crust. The earth and an
egg have layers that look alike. The upper portion of the mantle is hot liquid rock
called magma. In some areas of the earth water seeps below ground and is heated by the
hot rock. This hot water or steam can be used to turn a turbine that drives the generator
to make electricity in a geothermal power plant. Geothermal means earth-heat. California
generates one-half of the world's geothermal electricity. 
Fossil fuels were formed during the time of dinosaurs when plants and animals died. Their
decomposed remains gradually changed over the years to make coal, oil, and natural gas.
Fossil fuels are usually found below ground and must be either dug out or pumped from
below the ground. California produces about one-half of the oil it uses. The rest comes
from Alaska and other countries. Oil is transported in huge pipelines and tanker ships to
places where it is made into other products. Many products like plastic and fertilizer
come from oil. Natural gas is found near oil. Natural gas runs through a series of pipes
until it comes to our homes, schools, and businesses. Fossil fuels are not renewable.
They can't be remade.
Hydro power uses the kinetic energy of moving water. The moving water can be used to turn
wheels to grind grains or in a hydro electric power plant, to make electricity. Moving
water goes through a turbine spinning the shaft, which turns a generator to make
electricity. California's hydroelectric power plants are found along dams on rivers, and
in the mountains. 
Nuclear fission means splitting an atom apart. Splitting an atom releases heat and light
energy. In a nuclear power plant, an atomic chain reaction is controlled to produce heat
to boil water. That water boils water in pipes to make steam to turn a turbine and a
generator to make electricity. Nuclear fission means combining atomic nuclei to make a
larger nucleus. The sun uses nuclear fusion of hydrogen into helium to make light and
heat energy. Scientists are trying to create nuclear fusion to make a cleaner source of
power.
The oceans energy can be used in three basic ways. Wave energy systems use the up and
down motion of waves to turn a turbine or a generator. Tide energy systems traps high
tides in a reservoir. When the tide drops, the water behind the reservoir can flow
through a power plant, just like a regular hydroelectric plant. Ocean thermal energy
conversion uses the difference in temperature between warm surface water and cold deep
ocean water to make electricity.
Sunlight has always been a source of energy for plants, animals, and humans. We use
sunlight and heat from the sun to dry clothes outside. The sun's heat can be used to heat
water flowing through pipes on a roof. More than 500,000 solar water heating systems are
used in California. Sunlight can also be focused in a thermal system to heat water or
other fluids to make steam. The steam can be used to turn turbines to make electricity.
Sunlight can be used directly in solar cells or PV cells to make electricity.
Wind energy can be used to do work. Wind has been used for many years to drive boats and
windmills to grind grains or pump water. Wind turbines are being used today to make
electricity. Wind spins the large blades which turn generators inside the turbine to make
electricity. California's nearly 13,500 wind turbines can supply enough electricity to
power an entire city.
Electricity from power plants is sent through a transformer and boosted to a very high
voltage. The high voltage power lines carry electricity into cities and towns to
substations and to transformers to reduce the voltage. That lower voltage power then goes
to a smaller transformer near our homes, where power is reduced further. The lines can go
underground into our houses. At our homes, the power goes through a meter so the
electricity company can bill us for the power that we buy from them. Electrical wires are
not to be touched because they can cause injury or even death.
Natural gas is sent to us from the fields where it is found through a series of
pipelines. The pipelines carry the gas to factories, businesses, schools, and our homes.
The gas passes through a meter so the natural company can bill us for the natural gas
that we buy from them just like the electrical power. Natural gas burns very cleanly with
very little pollution. 
One-half of California's energy goes into powering vehicles. Oil made into gasoline and
diesel fuels are the main source of energy for cars, trucks, busses, and other vehicles.
Gasoline and diesel are transported to service stations in large tanker trucks. Fuels
other than gasoline and diesel are being used in alternative fuel vehicles.