ENAC has set up an accreditation scheme that includes requirements for inspecting facilities according to the different types of inspection to be carried out. At the request of and in collaboration with Enagás

Renewable gases (biogas and hydrogen, among others) can contribute to decarbonising the economy when using electrification presents greater technical or economic difficulties. One of the main promotion mechanisms for deploying renewable gases is determining a guarantee of origin system that accredits using renewable sources in their production.

Guarantees of origin for renewable gases (GoO) therefore becomes a key tool for promoting clean energy source development and reducing the carbon footprint, as they prove the renewable nature of gas and provide detailed information on its production.

A guarantee of origin is an electronic certificate that certifies the renewable nature of 1 MWh of gas and provides information on its production, such as the date of the energy's production, the type of installation or the place and source of energy used, its main function being to be able to demonstrate to the end consumer that a certain quota or quantity of energy has been obtained from renewable sources.

In Spain, guarantees of origin for renewable gases are regulated by Royal Decree 376/2022, of 17 May, "which regulates the criteria for sustainability and reduction of greenhouse gas emissions from biofuels, bioliquids and biomass fuels, as well as the system of guarantees of origin for renewable gases",  subsequently developed by Order TED/1026/2022, of 28 October, "approving the procedure for managing the system of guarantees of origin for gas from renewable sources.

A key element in developing this system of guarantees is the "auditing companies" regulated in the aforementioned TED order, and whose mission it is to carry out periodic controls on system compliance by the renewable gas production facilities registered in the system. In order to be sufficiently confident in how these companies perform, Enagás, as Technical System Manager and body responsible for the guarantees of origin system for gas from renewable sources, has set out the need for companies wanting to act as "auditing companies" to have the corresponding ENAC accreditation.

For this reason, Enagás and ENAC have collaborated in putting together the document defining the accreditation scheme based on the UNE-EN ISO/IEC 17020 standard. This document is already available on the Enagás website, so ENAC is already available to receive applications for accreditation and initiate the corresponding assessment processes.