Editor's note: this blog was submitted by Nicky Palmer, 7th grader in Foster City, California.
Did you know that if we add up all of the solar energy that is taken in by the Earth’s atmosphere, land and oceans every year, we end up with about 3,850,000 exajoules? To put it in more understandable terms, this amount of energy is equal to 2.7 million earthquakes of the same size as the 2011 earthquake in Japan. That's a lot of energy we can use!
Another cool thing is that NASA has been working on a series of solar powered unmanned aircraft since the 1980’s. Pathfinder, Pathfinder Plus and Helios Prototype, is the result of NASA’s efforts to use solar power for long duration high altitude flights. The Helios Prototype reached a record altitude of 96,863 feet in late 2001, which is the highest altitude reached by an aircraft that is not powered by rockets for sustained horizontal flight.
The main benefit of solar energy is that it does not produce any pollutants and is one of the cleanest sources of energy. It requires low maintenance and is easy to install. Solar energy is a completely free source of energy and it is found in a lot of places. Though the sun is 90 million miles from the earth, it takes less than 10 minutes for light to travel from that much of distance.
The sun has produced energy for billions of years. It is the most important source of energy for life forms. It is a renewable source of energy unlike non-renewable sources such as fossil fuels. Solar energy technologies use the sun's energy to light and heat homes, and produce hot water and electricity.
The reason that solar energy is a renewable energy source is that the electromagnetic radiation emitted from the Sun (also known as sunlight) will be around for us to harness, and will not disappear anytime soon. According to scientists, the Sun was born about 4.57 billion years ago and has another 6-7 billion years before it becomes a white dwarf (a planetary stage where the star begins to die). Fortunately you don’t have to worry about this. When the hydrogen reserves on the Sun are gone, it will expand into a red giant, and will likely swallow the Earth. Luckily we have another 5 billion years before this will happen!