Refers to normalised gross electricity production, adjusted for (1) weather conditions and including (2) indirect production of electricity from green gas.
Additional explanation to 1: Normalised production in a particular year is defined as the capacity in that year multiplied by the average production per unit of capacity in the past five years (wind) or fifteen years (hydropower). Essentially, the production of solar electricity also depends on weather conditions, but in the EU directive Renewable Energy it was agreed not to apply then normalisation concept on solar electricity.
Additional explanation to 2: Green gas is biogas upgraded to natural gas quality and injected in the gas grid. A (small) part of electricity production can be attributed to green gas. This attribution is included in normalised figures, but not in non-normalised figures.