We take stock of the system of guarantees of origin for renewable gases in Spain with Cecilia Pérez Mazuela, Business Analyst of Enagás GTS, invited as speaker to II Día del Biometano last May, in Seville. Cecilia explains that last year’s developments were very positive, and that almost 180,000 guarantees of origin have been issued. The GO system is fundamental for the development of the biomethane/RNG sector in Spain. Let's find out more in this interview.