How Does the Sun Produce Heat & Light?

The sun does not burn. Most of the fires that we see in everyday life is a chemical reaction between substances, usually including oxygen giving of heat and light. This process is also known as combustion. The belief that the sun does burn is a misconception.


The Sun is a hot ball of gas made up mostly of Hydrogen. The Sun is so hot that most of the gas is actually plasma, the fourth state of matter.

We all know that water in the form of ice is a solid. As we heat up ice it becomes water, a liquid which is the second state of matter.  As we heat up water, it becomes steam, a gas which is the third state of matter.

As we heat up the gas, atoms break apart. The negatively charged electrons in atoms are completely separated from the positively charged atomic nuclei (or ions) turning the gas into plasma.

In the very innermost part of the Sun, called its core, the temperature is about 15 million Kelvins, the density is 150 times that of water, and the pressure is over 250 billion times greater than atmospheric pressure here on Earth.

At such high temperatures and pressure, hydrogen nuclei smash into each other. They overcome the natural electrostatic repulsion that exists between the positive charges and fuse to form the heavier helium nuclei, releasing tremendous amounts of energy. This is called nuclear fusion.

Nuclear Fusion and Energy

Four hydrogen nuclei are fused to form one helium nucleus via a series of reactions called the proton-proton chain. Comparing the mass of the final helium nucleus with the masses of the four protons reveals that 0.7% of the mass of the original protons has been lost. This mass has been converted into energy. The amount of energy created is given by Einstein’s equation E=mc2, or, in words, energy equals mass times the square of the velocity of light. Because the velocity of light is a very large number (roughly 3 x 108 Km per second), even a small amount of matter can get converted into a huge amount of energy.

The energy produced by fusion is then transported to the solar surface and emitted as heat and light. Nuclear fusion also produces an elusive, minuscule particle known as a neutrino. These neutrinos have been used by physicists to know what’s going on inside the sun and what it is made of.

Scientists also study the vibrations of Sun tell us about interior structure, which is quite similar to using ultrasound to know about the interior of the human body. This study of the vibrations of Sun is known as Helioseismology.

The intensity of solar energy that reaches the top of Earth’s atmosphere (directly facing the sun) is 1,360 W/m². Even on a cloudless day not all this radiation reaches the ground. About 31% of the sunlight is reflected back by clouds, air molecules and the earth’s surface. Of the 69% that does not get reflected back, 23% gets adsorbed by dust, ozone and water vapor in the upper atmosphere, and clouds located in the troposphere.

The solar energy that we receive on earth is clean. The solar technology equipment, once constructed and put in place, uses this clean solar energy and does not need any other fuel to work. It also does not emit greenhouse gases or toxic materials. Using solar energy can drastically reduce the impact we have on the environment.

We are looking for Minnesota Residents that want to do their part to save our planet by going solar.  Contact us today and we will answer all of your questions, see what solar rebates you qualify for, and help you to make a difference and your own energy!

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