ISSUE NO 3: Solar Energy

Solar Energy

Nowadays our environment confronts climate change and dangerous pollution, for this reason world leaders are concentrating on how to use solar energy because this energy is the last resort to be away from climate change and its consequences. Solar Energy is a radiation produced by nuclear fusion reactions deep in the Sun’s core. The Sun provides almost all the heat and light Earth receives and therefore sustains every living being. Solar energy travels to Earth through space in discrete packets of energy called photons.
On the side of Earth facing the Sun, a square kilometer at the outer edge of our atmosphere receives 1,400 megawatts of solar power every minute, which is about the capacity of the largest electric-generating plant in Nevada. Only half of that amount, however, reaches Earth’s surface. The atmosphere and clouds absorb or scatter the other half of the incoming sunlight. The amount of light that reaches any particular point on the ground depends on the time of day, the day of the year, the amount of cloud cover, and the latitude at that point.
The solar intensity varies with the time of day, peaking at solar noon and declining to a minimum at sunset. The total radiation power (1.4 kilowatts per square meter, called the solar constant) varies only slightly, about 0.2 percent every 30 years. Any substantial change would alter or end life on Earth.
People have devised two main types of artificial collectors to directly capture and utilize solar energy: flat plate collectors and concentrating collectors. Both require large surface areas exposed to the Sun since so little of the Sun’s energy reaches Earth’s surface. Even in areas of the United States that receive a lot of sunshine, a collector surface as big as a two-car garage floor is needed to gather the energy that one person typically uses during a single day.

Prepared by:
Ibrahim Al-Bayati