Through Endesa Carbono, the subsidiary for the development and execution of initiatives in the carbon market and a pioneering enterprise in this sector, Endesa has 5% of the total carbon credits issued by the UNFCCC, the United Nations agency for climate change.

AENOR has been accredited by the UNFCCC as a Designated Operational Entity (DOE) to validate, verify and certify projects aimed at reducing greenhouse gas emissions. At the present time, AENOR carries out these activities in all geographical areas where such projects are found.

Among Endesa Carbono's projects is the Callahuanca hydro plant in Peru, the first project approved as a CDM by the Spanish regulating body, which has allowed the re-powering of the plant from 75MW to 82.5MW, with a resulting cut of 240,000 metric tons in CO2 emissions.