The company, based in Reno, Nevada, estimated the project will offset 83,000 tonnes of carbon dioxide emissions a year. Ormat said it has a long-term contract to sell all project CERs to a buyer in Europe, which it did not name.

The UN calls its registration a Clean Development Mechanism, or CDM. The Amatitlan project is Ormat's first registered CDM project and one of the few geothermal projects worldwide registered by the UN.

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