The Energy Payback Time is often used as a measure of the climate friendliness of an energy source. This is the time required to recover the energy that is consumed during production.
The figure below shows the Energy Payback Time of multicrystalline solar panels in Europe. In Belgium, it takes an average of one year and ten months before the energy needed to make a solar panel is recovered with that solar panel.
In countries with more sunshine this is sometimes the case after just one year, while the Energy Payback Time for solar panels in some less sunny countries sometimes amounts to 2 to 3 years.
If you know that the average lifespan of a solar panel is about 25 years, a solar panel is very quickly ‘earned back’ on an energetic level.