The overall power output of your solar panels depends on several factors, including their efficiency.
A solar panel is made up of solar cells, usually in a 6 x 10 formation. Scientifically speaking, the efficiency of a solar cell is worked out by looking at the amount of solar energy the cell is exposed to and how much of this is converted into electrical energy. This is then expressed as a percentage.
The average solar panel efficiency is around 11-15%, which may sound very low, but currently the world record for efficiency is approximately 20%. And even with an efficiency rating of 11-15%, most people can easily create enough power for all their needs using solar panels that take up just a portion of their roof space.