The sun provides sunshine for plants, animals , and people the on Earth.Energy from the sun is called solar energy.It comes in the form of light or heat.Solar energy makes you feel hot.People have used solar energy for thousands of years.Houses were built with windows so that sunlight can get inside and provide heat.The sun's energy can also be used to heat water and even food.
We can also turn the sunlight into electricity.This is done with solar panels（太阳能电池板）.Solar panels are made up of silicon（硅）.When the sunlight reaches the solar panel, the electrons （电子） in the silicon, move and flow through wires in the solar panel.
Using this technology , we can run even cars.But what happens when clouds block the solar panels? The electrons in the silicon will stop moving.But this doesn't mean that solar energy can only be used on bright sunny days.Solar panels can have batteries to store（储存）electricity for a rainy day.When the sun is shining, the electricity flows from the solar panels into the batteries.This stored electricity can be used at night or on cloudy days.
Solar energy is not as expensive as before.The sun produces more energy in one second than people have used since the beginning of time.Just imagine what we could do if we used the sun's energy to power our Earth.
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