Production Factor

From OGame Wiki

Production Factor is the output of your resource producing structures. A production factor of 1 means your buildings are at 100% efficiency, meaning you have enough power to power all of your buildings.

If you don't have enough energy output, then the production factor overall will be reduced. Each building will operate at reduced efficiency. For example, if your energy is negative, your production factor will be less than 1 and instead of producing x number of a certain resource, it will produce x times the production factor.

Get the production factor back up by upgrading your power plants, or, reduce the production at one of the buildings if you want to keep a high priority building running at full capacity by going to the resources page, reducing the production from 100% for one or more of the buildings then hit calculate.