Energy From the Sun
What is 109 times the diameter of the Earth, weighs 330,000 times the weight of the Earth, and has 98% of its composition as hydrogen and helium? That bright mass in the sky (during the day) is the sun. It is the source of energy for growth, for warmth, and increasingly is being used to provide electrical energy.
News You Can Use
- The sun is a gigantic nuclear fusion process. Laboratories on Earth have been trying to produce sustained nuclear fusion reactions for quite some time.
- Major problems in getting energy from nuclear fusion include the extremely high temperatures needed to start the fusion process and the lack of materials that can contain the reaction once it has started.
- The process looks simple on paper – collide hydrogen nuclei to form helium nuclei and release photons (light energy). The sun can do this since the internal temperature is about 15 million K.
- Although we can’t reproduce the fusion reaction that the sun carries out, we can take advantage of the energy released by the sun. Since the photons (light) have some properties of particles, we use the photoelectric effect explained by Einstein to generate electricity.
- First developed to provide power for space vessel electronic systems in the late 1950s, solar panels are now common features in a variety of business and residential buildings. Many pocket calculators are solar-powered, needing only a small amount of light to operate. Some solar panels have been integrated into roofing materials, leading to lower cost and easier installation. Solar cells (smaller than a grain of rice) in windows allow generation of electricity without affecting visibility. The energy produced by this “simple” fusion reaction has many uses, and more applications will be developed in the future.
- Watch the video at the link below to see the sun in action:
Show What You Know
With the links below, learn more about energy from the sun. Then answer the following questions.
- How is energy produced in the sun’s fusion reaction?
- Where is the sun’s energy produced?
- What is one way solar energy could be stored as electricity?
- What is a typical power output we could expect from the sun on one square meter of the Earth’s surface?