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Article - 10/07/2020

GHG Abatement Facilities in GPPs Worldwide

In a project commissioned by Enel Green Power (EGP); Mannvit and EGP conducted a worldwide mapping where information for geothermal power plants (GPPs), was gathered and inserted into a database for all geothermal fields with installed capacity over 200 MW.

A paper named Overview of Global Existence of Pollutant and GHG Abatement Facilities in GPPs on the subject was submitted to the World Geothermal Congress (WGC) which will take place in Reykjavik in May 2021. The authors of the paper are Alessandro Lenzi, Marco Paci from Enel, and from Mannvit the authors are Lilja Tryggvadottir, Teitur Gunnarsson, Katrin Ragnarsdottir.

The database
The list of GPPs was then extended to fields with installed capacity less than 200 MW, by including some plants that showed to be of particular interest due to installed abatement systems, the history of installed abatement systems or the type of fluid. The resulting list of geothermal areas comprises 30 geothermal areas with approximately 125 GPPs (over 265 units). The gathered available information consisted mainly of basic plant description, year of construction, owner, installed capacity and information on a few parameters of environmental interest. Despite the conscious addition of plants with abatement systems to the list the abatement of pollutant or GHG was noted in only 63 GPPs within 13 geothermal areas of the investigated 125 GPPs in 30 geothermal areas.

Italy had most GPPs with operating treatment facilities. This is not surprising since Italy has strict regulations for emission limits and air quality and H2S/Hg abatement systems have been installed in all Italian GPPs. Of the total 63 GPPs with treatment facilities, 35 of them are in Italy, 19 are in the USA, and further 15 of those 19 are in the Geyser geothermal area. Nevada and California in the USA have strict ambient air quality standards and most of the GPPs there have H2S abatement systems. The Philippines has no operating treatment facilities even though some abatement systems have been tested or implemented there, they were however deemed unnecessary and therefore shut down.

Treatment Facilities
The scarcity of treatment facilities in operation in connection to environmental enhancement of the plants is intriguing. To investigate the reason why, the incentive for implementation of abatement systems was studied. Regulations for air emissions and wastewater do not require treatment from most of the GPPs in the countries studied. The countries studied represent the largest geothermal producers and countries with longest history of geothermal energy utilization such as USA, Mexico, Philippines, Iceland, Indonesia, Italy, Kenya, New Zealand, Turkey and Japan.

The paper itself will be shared on after the WGC 2021 and we look forward to meeting the delegates at the WGC2021 in Reykjavik.