Video transcription

Hi, I'm Steve Jones and I'm going to tell you something about solar energy. As you can see, we've got a list of renewable energies here of which solar is one and fossil fuels which solar is not. So solar energy is a renewable energy. The question is where does it come from? Well it comes from this, which is called a silicon chip. Now a silicon chip isn't a simple thing, although silicon itself is very, very common. All rocks contain silicon, silicon dioxide. So silicon is a very, very common material. The problem is to create this chip, you need a pure crystal of silicon and this is very expensive to grow and then to cut. So silicon chips are quite expensive, particularly in the sizes that you need for a solar panel and what we've got then is a process where radiation comes from the sun and it lands on the silicon chip and the result is a small electric current comes out of it. Now the electric current to come out of one silicon chip is minute and therefore we have to put lots and lots of these silicon chips together and we call that an array. And usually you will see arrays of silicon chips in the solar panels. You can see them, they're kind of a set of squares. And those can be placed for example on the roof of a house and if they're all connected together, each one from a separate piece of wire, then you will find that the current out is quite large. You can get a large current up to 10 amps for a common household unit. This is enough to drive a heater, drive lights in a house. So solar energy requires a large array, each producing a tiny current and these can put together produce a current which is good enough to drive your home. The only problem is, when it goes dark.