Energy from the Sun

Think about your day — you woke up in a warm house, ate food from the kitchen, looked outside at a bright sky, and the wind might have been blowing. Every one of those things connects back to energy from the sun. The sun is the primary energy source for almost everything that happens on Earth.

Two types of solar energy

• Light energy — the sun's light travels 93 million miles through space and reaches Earth in about 8 minutes.
• Heat energy — the sun's rays warm the ground, the oceans, and the air around us.

Use 1 — Photosynthesis (plants making food)

• Plants capture sunlight with their leaves using a green chemical called chlorophyll.
• They combine light energy + water + carbon dioxide → sugar (food) + oxygen.
• This is called photosynthesis. It feeds almost every living thing on Earth — including us — because animals eat plants or eat animals that ate plants.

Use 2 — Solar panels (making electricity)

• Solar panels are devices that capture sunlight and convert it directly into electricity.
• They are placed on rooftops, in solar farms, and even on spacecraft.
• Solar energy is renewable — the sun will not run out for billions of years.

Use 3 — Warming the Earth

• The sun's heat warms the ground and oceans. The ground then warms the air above it.
• Without this warmth, Earth's average temperature would be far below freezing and life could not exist.

Use 4 — Driving weather and the water cycle

• Sun heats water → evaporation → clouds → rain (the water cycle).
• Sun heats the ground unevenly → warm air rises, cool air rushes in → wind.
• The sun is the engine that powers all of Earth's weather.