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CDM’s Executive Board approves revision of methodology for geothermal projects

BONN, 16 May 2016 - CDM’s Executive Board has approved a revision of CDM methodology ACM0002 for renewable energy projects. The revision, which had been proposed by MidSEFF consultants, will allow geothermal energy projects with binary or closed-loop heat exchange systems to be credited with more carbon credits. The Babadere Geothermal Power Plant (GEPP), a project financed and supported under MidSEFF, is applying such technology.

Without the revision, Babadere GEPP would not be credited for all the greenhouse gas emission reduction from their investment. The old methodology is applicable for those geothermal plants that use open cycle (i.e. dry steam or flash steam) systems for their heat exchange between underground geothermal heat source and the plant’s power generation facility. With open cycle systems you will need to account for greenhouse gas emissions from the steam. However, in a closed loop or binary geothermal technologies, the underground fluid is re-injected back to the heat source without any exposure to the atmosphere. In this case, non-condensable and other gases within the geothermal fluid are kept within the outgoing geothermal fluid and sent back into the heat source. Project emissions in this case are near to zero and negligible.

In most cases the amount of CO2 in the steam is typically low. However, in the case of Turkey the amount of CO2 in the steam can be high, in some cases equal to or even higher than CO2 emissions from electricity generated by a coal fired power plant. See the approved methodology here.