Trace electricity with an hourly time step, so that green energy offers accelerate decarbonization

A guarantee of origin is a certificate attesting that a quantity of green electricity has been produced and injected into the European Union grid. These guarantees are very popular in France: their volume has risen from 42 TWh in 2019 to 79 TWh in 2023, representing growth of over 17% per year, and is set to continue. However, this system is based on matching certificates (guarantees of origin) on a monthly basis. In other words, it is possible to link a guarantee of origin to any consumption in the same month, without ensuring that production and consumption took place at the same time. Moreover, the current system also allows production and consumption to be matched at either end of the continent, without any limitations. Therefore, by maximizing these spatial and temporal inconsistencies, it is possible to construct 100% green offers very easily and without nuance. However, without reflecting the physical reality of the power grid, they cannot contribute to the decarbonization of the grid. We recommend that the French system of matching guarantees of origin and consumption be moved as soon as possible to an hourly (or sub-hourly) time step, and that limits be imposed on the location of generation and consumption. To this end, the progressive changes we recommend, in order of importance but also ease of implementation, to make France a leader in this field, are as follows: 1: Give producers the option of issuing guarantees of origin on an hourly basis. Having hourly certificates does not mean imposing hourly matching, and this choice - which does not require any legislative change - will have no impact on most consumers, but will provide those who so wish with an instrument to prove their hourly matching; - 2: take advantage of the transposition of the European RED III directive to change the unit of a guarantee of origin in France to kWh or Wh; - 3: Encourage hourly and geographical matching on a voluntary basis, in particular through voluntary initiatives promoting hourly or sub-hourly matching such as Ademe's VertVolt label or Carbone 4's Net Zero Initiative; - 4: Encourage other European Union member states to step up their efforts in this area, and encourage the inclusion of physical limits on trade between European Union countries; - 5: impose hourly matching for all consumption in order to benefit fully from the advantages mentioned above