for hundreds of years. Ships with sails have depended on wind for even longer. Wind can
be used to generate electricity, too. Like the moving water that creates water power, the
moving air can make a turbine spin to make electricity.
To help you understand how moving air can be used to make electricity, you could think
back to what you have learned about energy of motion, called kinetic energy. Any form
of matter that is moving has kinetic energy. Even though you cannot see air, it is matter,
because it takes up space and has mass. So, when wind makes the air move, this air has
kinetic energy. When the moving air hits the blades of a turbine, it makes those blades
move, and the turbine spins. The spinning of the turbine creates electricity.
Windpowerhasmanyadvantages. Itiscleanenergy,meaningthatitdoesnotcausepollution
or release carbon dioxide. Also, wind is plentiful almost everywhere. One problem with wind
energy is that the wind does not blow all of the time. One solution is to find efficient ways to
store energy for later use. Until then, another energy source needs to be available when the
wind is not blowing. Lastly, windmills are expensive and wear out quickly. For the amount
of energy they generate, windmills are more expensive than some other forms of renewable
energy.
California was an early adopter of wind power. Windmills are found in mountain passes,
especially where cooler Pacific ocean air is sucked across the passes and into the warmer
inland valleys. Large fields of windmills can be seen at Altamont pass in the eastern San
Francisco Bay Area, San Gorgonio Pass east of Los Angeles, and Tehachapi Pass at the
southern end of the San Joaquin Valley.
Biomass
Another renewable source of energy is biomass. Biomass is the material that comes from
plants and animals that were recently living. Biomass also includes the waste that plants and
animals produce. People can use biomass directly for heating. For example, many people
burn wood in fireplaces or in wood-burning stoves.
Besides burning biomass directly for heating, people can process biomass to make fuel. This
processingmakeswhatiscalledbiofuel. Biofuelisafairlynewtypeofenergythatisbecoming
more popular. People can use fuels from biomass in many of the same ways that they use
fossil fuels. For example, some mechanics have made changes to car, truck, and bus engines
to allow them to use a fuel called biodiesel. Other engines can run on pure vegetable oil or
even recycled vegetable oil.
If we use fuels made from biomass, we can cut down on the amount of fossil fuel that we
use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can
mean that we will put less of this gas into the air overall. This could help us do something
about the problem of global warming.