Today’s Wonder of the Day was inspired by sohail. sohail Wonders, “How Solar Panel works” Thanks for WONDERing with us, sohail!

Do you look forward to the weekend? If you're like most kids, Saturday beckons with the call of free time to do all sorts of things you don't have time to do during the week. You can sleep in, ride your bike, go for a hike, play games with your friends outside, and stay up later than on weeknights.

All those hopes can be shattered, though, when you wake up on a Saturday to cloudy skies that promise rain. At those times, you may wish that you could head to the pantry and grab a jar of sunshine off the shelf. Wouldn't that be great? All you'd need to do is take your jar of sunshine outside, open it, and let the sunshine fill the skies.

It's too bad that the world doesn't really work that way. We might not be able to bottle rays of sunshine, but clever scientists have found a way of collecting sunlight and storing its energy to use as electricity. Do they use glass jars? Nope! They use solar panels and batteries.

Solar power has become an increasingly popular alternative energy source over the last couple of decades. You can see solar panels on residential homes, schools, office buildings, and even road signs and traffic lights. Solar panels can also power everything from simple calculators to the International Space Station.

A solar panel consists of a group of photovoltaic cells linked together. As their name suggests, these cells convert light ("photo") into electricity ("voltaic").

Each photovoltaic cell is like a sandwich made with two slices of semiconducting material, which is usually silicon. In its pure crystalline form, silicon is not a good conductor of electricity. That's why the silicon layers in a photovoltaic cell have impurities added to them to give each layer a different charge.

Phosphorus gets added to the top layer of silicon to give it a negative charge. Likewise, boron gets added to the bottom layer to give it a positive charge. These opposing charges create an electric field between the layers of silicon.

When arranged together in a solar panel, the photovoltaic cells just need sunlight to work. As small particles of light, known as photons, hit the photovoltaic cells, they knock electrons free, creating a flow of electricity.

Metal plates attached to the sides of the photovoltaic cells transfer the flowing electrons to wires, which direct the flow of electricity like any other source of power. For example, those wires can be connected to a machine that will use the electricity. Alternatively, the wires could be connected to a battery that will store the electricity for use at a later time.

Wonder What's Next?

You might want to bring an umbrella to Wonderopolis tomorrow…and a vase!