What is solar energy and how does solar energy create electricity? Lets first have a look at the sun, because to understand What solar energy is we first have to know a little bit about the sun. The sun is actually a star, it's the same as the many millions of stars that you see every night, burning in the sky. Just out of interest I saw a scientist being interviewed on TV. And he was asked how many stars there were. He said they were uncountable, he said look at it like this. There are more stars than all the grains of sand, on the whole of this planet. I guess that's why he said they are uncountable.
Let's get back to the question of What is solar energy. Our sun is really just a continuous nuclear reaction. The whole of that yellow ball you see every day is nuclear fusion. The heat you feel is from that nuclear reaction. This whole process releases particles that are called protons. Some of these protons are millions of years old and have been held within the suns core. However every second some of these protons are released from the suns core by the violent nuclear reactions within the core of the sun. These violent explosions cause some of the suns energy to be shot into space. This includes protons.
The speed of Light and protons What is solar energy?
These protons that are expelled from the sun are travelling at the speed of light, Learn more about the speed of light here. It would take a proton approx 8 minutes and 20 seconds to reach the earth if nothing gets in its way. Now the interesting stuff happens, our proton that just minutes ago was a part of the sun, or let's call it a bit of a star sounds more romantic reaches us. Normally that's it we would feel a little heat and see the light, and that's about it. However, when our friendly proton hits a photovoltaic cell, it creates electricity.
How does that make electricity?
Good question, the photovoltaic cell is explained in a blog post we wrote here. But here is a slimmed-down and quick version. When the photon hits a solar panel, it knocks over an electron. It's this process that creates electricity within the solar panels. The Power generated Is then either used or stored.
And here we come to one of the big problems with solar power, to store it in your house is quite easy. I use old car batteries that have been re-energised. That is more than enough for me to store solar power for later use. I can easily store enough for use at night.
Batteries and storage.
Although there have been huge leaps in storage technology, there is still a very long way to go. That's why billions are being invested in this technology, its a race to find the ultimate storage solution. Whoever wins is going to be very rich, as this storage technology will be used in cars as well as homes and factories. One working solution is in Morocco. The Noor Project (Noor Means Light in Arabic) is currently producing power at night from energy saved from the solar panels through sunshine.
The Noor project has opened the first part of its solar field and can supply a part of the Moroccan electrical grid through the day. However more importantly it can supply three hours of stored power at night, it uses molten salt to store this solar energy. You can read more here.
This project when it is finished will be able to produce electricity 24 hours a day from clean unlimited solar energy. Morocco will become a big provider of energy to Europe. Via the undersea cables running from Tangieries to Europe under the Gibraltar straights.
Summary What is solar energy?
As you can see the ability we have to produce solar energy is huge. The problems come when we have to store the electricity on a large scale for later use. We hope this post has answered some of your questions about What is solar energy. If you have more questions please leave a comment.