An electricity supply offer is said to be “green” if the supplier can guarantee that a quantity of electricity of renewable origin equivalent to the consumption of the customers of this offer has been injected into the network. To prove this, only the Guarantees of Origin (GO) have certification value.
Guarantees of Origin ensure, at the European level, the administrative traceability of green electricity. These are electronic certificates issued to producers in proportion to the quantity of electricity produced from renewable energy sources.
Our electricity comes mainly from hydraulic energy. This energy includes the energy provided by the movement of water in all its forms: waterfalls, rivers, ocean currents, tides, waves. Hydraulic (mechanical) energy is converted into electrical energy in hydroelectric power plants. This renewable electricity is used not only to light the terminals, runway and aprons, but also to recharge the site’s electric vehicles and to supply energy to the aircraft in transit.
Depending on the supplier and the year, electrical energy is produced in countries that have a surplus of electricity production:
Iceland: at Búrfellsstöð (2019), Fljótdalsstöð (2020, 2018), Sultartangastöð (2021). These power plants use the force of water movement from dams and the force of the water movement of several lakes and rivers.
Norway: at Nes (2021), Kvænangsbotn (2019), Sagefossen (2017), Svelgen (2017), Øksenelvane (2017, 2016), Leirdøla (2016), Makkoren (2016), Åskåra (2016), Mageli (2016), Oksla (2015). Tokke (2015), Jostedal (2015), Aurland (2015), Svorkmo (2015), Mår (2014) and Nore (2014). These power plants use the force of water movement from several lakes and rivers.
The release of greenhouse gases (GHG) into the atmosphere depends mainly on the activity and the process of electricity production. Depending on the different production methods, to estimate the GHG emissions per unit of electrical energy (kWh), there are internationally and European recognized factors called emission factors (EF).
An emission factor is a coefficient used to convert activity data into GHG emissions, which corresponds to the average emission rate of a given source expressed in kg of CO2 per kWh. For any production of electrical energy using renewable primary energy (wind, solar, wood, geothermal, etc.), this factor is 0. As an example, this rate is 0.215 kg CO2 /kWh for the electric mix in Luxembourg and it increases to 2.58 kg CO2 /kWh for the diesel used in cars. This rate increases to 0.461 kg CO2 /kWh in Germany because of the use of fossil fuels to produce electricity.
Emissions related to the manufacture and maintenance of the generating device are accounted for in the energy producer’s carbon footprint. The use of renewable electrical energy is therefore considered emission-free.
A human activity emits different types of greenhouse gases (GHG). Their global warming potential (GWP), which is a physical characteristic of GHGs, represents their impact on the greenhouse effect and allows us to convert 1 kg of GHG into X kg of CO2 equivalent, noted CO2eq. In this way, the emissions of different gases can be compared.