What is Solar Energy and How Do We Use It
Every day, the sun emits (sends out) a huge amount of energy. It emits more energy in a single day than the world uses in an entire year. Solar energy is a renewable energy source.
The sun’s energy comes from the core of the sun itself. Like most stars, the sun is made primarily of hydrogen and helium atoms in a plasma state. The sun produces energy through a process called nuclear fusion.
During nuclear fusion, the high pressure and temperature in the sun’s core cause nuclei to separate from their electrons. Hydrogen nuclei fuse together to form a helium nucleus. During the fusion process, radiant energy is released. It may take 150,000 years for the energy in the sun’s core to reach the solar surface, and just a little over eight minutes to travel the 93 million miles to Earth. Radiant energy travels to Earth at 186,000 miles per second, the speed of light.
Only a small percentage of the energy the sun emits into space reaches Earth—about one part in two billion. However, that amount of energy is enormous. The sun provides more energy in one hour than the United States can use in a whole year! About 30 percent of the radiant energy that reaches Earth is reflected back into space. About half of the radiant energy is absorbed by land and oceans. The rest is absorbed by the atmosphere and clouds in the greenhouse effect.
In addition to providing a large amount of energy directly, the sun is also the source of many different forms of energy. Solar energy powers the water cycle, allowing us to harness the energy of moving water. Solar energy drives wind formation, enabling us to use wind turbines to convert kinetic energy into electricity. Plants use solar energy in the process of photosynthesis. Biomass can trace its energy source back to the sun. Even fossil fuels originally got their energy from the sun.
How We Use Solar Energy
Humans have harnessed solar energy for centuries. Since the 7th century BC, people used simple magnifying lenses to focus sunlight and start fires. Over a century ago, a scientist in France used a solar collector to produce steam and power a machine. Solar water heaters gained popularity in the early 1900s in the southwestern United States. Today, people use solar energy to heat buildings and water and to generate electricity. More historical facts here
MSc in Environmental Education
Specialization in Educational Robotics and STEM
Specialization in E-learning and Educational Content Production
Certified Adult Educator
