Additionality principle

Overview of the status and impact of the innovation



Green hydrogen needs to be produced with renewable electricity. The additional demand from green hydrogen production might reduce renewable energy available for other sectors, delaying the overall decarbonisation of the energy sector. “Additionality” for grid-connected green hydrogen means that the production is accompanied by an additional source of renewable energy capacity, and implies that there is a degree to which this additional capacity needs to be matched in space (geographical correlation) and time (temporal correlation).


The additionality principle is very important to ensure that increasing renewable electricity demand for renewable hydrogen production will not compete with the renewable electricity that should go into the direct electrification of other processes across the economy. This principle aims to ensure that the generation of renewable hydrogen incentivises an increase in the volume of renewable energy available to the grid compared to what exists already. In this way, hydrogen production will be supporting decarbonisation and complementing electrification efforts, while avoiding pressure on power generation.

BOX 9.6 The European Commission’s Delegated Act on renewable hydrogen, February 2023

The European Commission has proposed detailed rules to define what constitutes renewable hydrogen in the European Union, with the adoption of two Delegated Acts required under the Renewable Energy Directive. The first Delegated Act defines under which conditions hydrogen can be considered green. The Act clarifies the principle of “additionality” for hydrogen. Electrolysers to produce hydrogen will have to be connected to new renewable electricity production.

While initial electricity demand for hydrogen production will be negligible, it will increase towards 2030 with the massive roll-out of large-scale electrolysers. The European Commission estimates that around 500 TWh of renewable electricity is needed to meet the 2030 ambition, which corresponds to 14% of total EU electricity consumption in 2030. This ambition is reflected in the Commission’s proposal to increase the 2030 target for renewables to 45%.

The Delegated Act sets out different ways in which producers can demonstrate that the renewable electricity used for hydrogen production complies with additionality rules. The primary requirement is that the hydrogen production unit must be directly connected to a renewable generating asset that did not come into operation more than 36 months before the hydrogen plant.

If an electrolyser is connected to the main grid, it has three options for considering the hydrogen produced as green:

  • If the proportion of renewable power exceeds 90% over the previous calendar year in the bidding zone where the electrolyser is operating.
  • Hydrogen production takes place in a bidding zone where the carbon intensity of the grid is lower than 18 grams of carbon dioxide per megajoule (gCO2/MJ). The electrolyser must acquire a renewable power purchase agreement, with temporal and geographical consideration.
  • Power supply can be considered renewable if taken from the grid during an imbalance period (when there is downward re-dispatchment of renewables).
  • A renewable power purchase agreement where the principles of additionality, temporal and geographical correlation apply. Temporal correlation is considered to be always met if the hydrogen production occurs within the one-hour period when the clearing price for power resulting from the day-ahead market is lower than or equal to EUR 20/MWh, or lower than 0.36 times the EU Emissions Trading System.
Source: (European Commission, 2023; Stones, 2023).