On the left: Part of the solar energy is lost in its way through the atmosphere by the effects of reflection and absorption.

On the right: Space-based solar power systems are an attempt to convert in space, outside the atmosphere, to avoid these losses.

 Now we know that solar power relies on energy that filters down from the sun - but imagine how much energy you could collect if you went straight to the sun itself.

Well Europe's biggest space company wants to do just that. They want to send a satellite system into space, where it would collect the Sun's energy and transmit it back to Earth where it could be used as electricity.

It's been talked about for years - but now the company planning the mission reckon they can make it happen.