Figure 5.6: Solar panels like these can turn the sun’s energy into electricity to provide power
to homes. ( 2 )
Solar power plants are in the works for southeastern California, near the California-Nevada
border.
Solar energy is used to heat homes, to heat water, and to make electricity. Solar energy can
be used to heat the water in your pool or to heat tile floors in your home. In recent years,
scientists and engineers have found new ways to get more and more energy from this resource
(Figure below). Because there are many different uses for solar energy, there are also many
different ways of turning the sun’s energy into useful forms. One of the most common ways
is by using solar cells. Solar cells are devices that can turn sunlight directly into electricity.
You may have seen solar panels on roof tops. Lots of solar cells make up an individual solar
panel.
Solar power plants turn sunlight into electricity using a large group of mirrors to focus
sunlight on one place, called a receiver (Figure5.8). When a liquid, such as oil or water
flowsthroughthisreceiver, thefocusedsunlightheatstheliquidtoahightemperature. Then,
this heated liquid transfers its heat byconduction. In conduction, energy moves between
two objects that are in contact with one another. The object that is at a higher temperature
transfers energy as heat to the object that is at a lower temperature. For example, when
you heat a pot of water on a stove top, conduction causes energy to move from the pot to its
metal handle, and the handle gets very hot. In the case of the solar power plant, the energy
conducted by the heated liquid is used to make electricity.
Solar energy has many benefits. It does not produce any pollution. Also, there is plenty
of it available. In fact, the amount of energy that reaches Earth from the sun every day is