UNIMAGINABLE ENERGY RESERVES
The solar energy striking Earth’s atmosphere each year is an
unimaginable 1,500,000,000,000,000,000 kilowatt hours.
This corresponds to about 10,000 times the energy
consumption of all of humanity (as of 2010).
By comparison: A 3-person household in a single-family
home consumes 4000 kilowatt hours of power each year on
average, which is but a tiny fraction of the incident solar
energy.
However, a large portion of the solar energy is lost in the
atmosphere, since it is “swallowed up” there or reflected
back. The rest of it is enough, though, to give us sunlight that
we can make use of technically.
INDIRECT USE
By the way, solar radiation is also
responsible for the differences in air pressure
in the atmosphere that cause wind. Earth’s
water cycle is also “driven” by solar energy.
That’s why it’s also possible to use solar
energy indirectly to produce energy:
• The plants and plant wastes that we
process into useful liquids such as cooking
oil and biogas — with which automobiles
can be powered — depend on sunlight to grow. Even the petroleum and
natural gas that we use to make fuels, lubricants and plastics, could not have formed wit
energy radiating from the sun. They are vast underground storehouses of solar energy.
• power stations generate electric current.Wind and water
• So-called passive solar energy heats houses, thus reducing the energy required for heating.
ENERGY FROM THE SUN
“Solar energy” and “solar power” refer to the energy of the that we are able to exploit solar radiation
technically.
The sun is a star that is 150 million kilometers from our Earth, on average. But despite this immense distance,
solar energy has an enormous impact on our life. More precisely, life is not possible without the sun!
You can feel how strong solar energy is on any sunny day. Just lay out for a bit in the sun in the middle of
summer. But be careful — you need to protect yourself adequately against sunburn. The sun emits so much
energy because it is a gigantic nuclear reactor. It is so hot on the inside that the atoms, the building blocks of
all matter, fuse together. Even on the sun’s surface, it is still around 5500 degrees Celsius. The nuclear fusion
produces nearly inexhaustible amounts of energy. This is radiated out into space. And some of it strikes the
Earth’s surface as electromagnetic radiation, as light.