Fuel mix disclosure
Your electricity supplier: ewz
Contacts: www.ewz.ch, phone 058 319 41 11
Reference year: 2023
The figures show the composition of ewz’s electricity products based on data for 2023.
Where does my electricity come from?
The European electricity grids are interconnected to form a larger electricity grid. The best way to imagine the entirety of the produced electricity is as a pool of electricity: all electricity producers feed their electricity into this pool and all electricity consumers draw electricity from it. With green electricity, we jointly ensure that the pool is getting cleaner all the time – by producing green electricity for our part as electricity producers, and by purchasing green electricity on your end as consumers. With your demand for natural electricity, you are therefore making an important contribution to replacing fossil and nuclear energy.
What are certificates of origin (HCN)?
Once the electricity has flowed into the pool it is no longer possible to determine from which source it originates. The source of electricity is therefore verified by means of certificates of origin. For every kilowatt-hour produced, the certification body Pronovo (in German) issues a certificate of origin to the electricity producer. It provides information on the electricity quality (e.g. coal, solar, wind, etc.) and on the production plant or in which country or region (Switzerland, EU, etc.) the electricity was produced. In addition, the certificate of origin shows whether the electricity has a sustainability label and, if so, which one (e.g. naturemade star). The certificates of origin are traded as independent certificates. On the one hand, these certificates prove that your electricity product has the desired properties. On the other hand, the certificates allow you as an end user to understand the composition of your electricity products. Information on the composition can be found in the fuel mix disclosure published annually.
How can the origin of electricity be traced?
In order to prove the origin of electricity, the relevant electricity source is confirmed with certificates of origin. For every kilowatt-hour produced, the accredited certification body Pronovo (in German) issues a certificate of origin to the electricity producer. With this certificate, the suppliers guarantee the environmental quality of the produced electricity to end users.
How does the certificate of origin system work and who is responsible for it?
The proof of origin system is an electronic accounting system. In Switzerland, there is both a statutory recording obligation for each kilowatt-hour (kWh) produced and a statutory declaration obligation for each kWh consumed by end customers. Through the certificate of origin system, the certificate of origin is sent from the operators of electricity production plants directly or via intermediary trade to the electricity suppliers, who validate it when their end consumers consume it. In the certificate of origin system, the validation takes place either for the electricity product or for the end customer. A certificate of origin can only be used once – after it has been validated, it is ‘used up’ and no longer available. On behalf of the Swiss Federal Office of Energy, Pronovo (in German) is responsible for the Swiss certificate of origin system as an accredited certification body for the registration and validation of certificates of origin.
Can foreign certificates of origin also be used for the fuel mix disclosure?
The Swiss certificate of origin system is part of the European Energy Certificate System (EECS), which greatly simplifies the tradeability between the currently 30 European certificate of origin registers. ewz, for example, imports certificates of origin produced in its own wind power plants in Norway or France and uses them in the basic supply products that are delivered to market customers. The export of Swiss certificates of origin to European countries has been suspended since 2021 because, from the EU’s point of view, Switzerland is a third country without a framework agreement. Swiss certificates of origin are therefore no longer recognised.
Do the rates for the basic supply include energy from non-renewable sources?
ewz produces renewable energy in its own and in partner power plants. We have been supplying our basic customers (households, SMEs) with 100% renewable energy (green electricity) since 2015 and all customers since 2019. Our electricity products in the basic supply system (ewz.econatur, ewz.natur and ewz.pronatur) do not contain nuclear energy, nor do we have any investments in coal-fired power stations.
