“Guarantees of Origin (GO) are electronic certificates that are intended to prove to the final consumer the share or amount of energy from a certain source through a certain technology, present in the energy mix of a given supplier.
In particular, variants of these certificates are considered in Portugal for:
- electrical energy produced from renewable energy sources;
- energy for heating or cooling produced from renewable energy sources;
- electrical energy produced in cogeneration installations operating under the high efficiency or efficient regime.
Note that there is no place for double counting as the GOs for renewable energy sources are intended to reveal to the consumer the origin of the energy consumed while the cogeneration GOs are used essentially to prove the existence of primary energy savings in a certain installation cogeneration and as a result it can benefit from a subsidized remuneration regime.” Source: http://www.dgeg.gov.pt/pagina.aspx?js=0&codigono=63638824AAAAAAAAAAAAAAAA