Solar Energy

What is Solar Energy?

Every day, the sun radiates (sends out) an enormous amount of energy—called solar energy. It radiates more energy in one second than the world has used since time began. This energy comes from within the sun itself. 

Like most stars, the sun is a big gas ball made up mostly of hydrogen and helium gas. The sun makes energy in its inner core in a process called nuclear fusion. It takes the sun’s energy just a little over eight minutes to travel the 93 million miles to Earth. Solar energy travels at a speed of 186,000 miles per second, the speed of light.

Only a small part of the radiant energy that the sun emits into space ever reaches the Earth, but that is more than enough to supply all our energy needs. Every day enough solar energy reaches the Earth to supply our nation’s energy needs for a year! Solar energy is considered a renewable energy source. 

Today, people use solar energy to heat buildings and water and to generate electricity.

Energy from the sun can be used in three main ways, and when talking about solar energy, it is important to distinguish between these three types:

• Passive heat: This is heat which we receive from the sun naturally. This can be taken into account in the design of buildings so that less additional heating is required
• Solar thermal: Uses the sun’s heat to provide hot water for homes or swimming pools (also heating systems)
• Photovoltaic energy (PV): Uses energy from the sun to create electricity to run appliances and lighting. A photovoltaic system requires only daylight - not direct sunlight - to generate electricity.