Successful tests of capturing and reinjecting geothermal CO2, NZ

Successful tests of capturing and reinjecting geothermal CO2, NZ Ngatamariki geothermal power plant by Mercury, Taupo/ NZ (source: ThinkGeoEnergy)
Alexander Richter 14 Aug 2022

New Zealand's Mercury Energy is successfully testing capturing and reinjecting CO2 emissions from geothermal operations at Ngatamariki.

New Zealand is making steps towards removing carbon emissions from its geothermal operations, as reported today locally.

Despite lower carbon emissions than fossil fuel based power generation, some of the geothermal plants in New Zealand have been targeted for closing, based on the country’s Climate Change Commission in its draft climate roadmap.

There are though now tests ongoing on capturing emissions and reinject them back into the ground.  Mercury Energy is testing it at its Ngaatamariki geothermal power station north of Taupo on the North Island of New Zealand. The plant is now not only producing reliable, green electricity it is doing it without emissions.

There is though also natural de-gassing of geothermal fields, according to Isabelle Chambefort of GNS. Capturing and reinjecting both carbon dioxide and hydrogen sulphide is rather complex.

The trial at Ngatamariki at one of its four operating units, has been running “successfully” for seven months capturing very close to 100% of the greenhouse gases for the unit, according to Vince Hawksworth, CEO of Mercury.

Icelandic company CarbFix, a startup of Icelandic geothermal energy company Reykjavik Energy and a pioneer in this sector, is already working with air capture technology by Swiss company Climeworks in at the Hellisheidi geothermal power plant inIceland. The company is reinjecting CO2 into the basalt and mineralises CO2 in the basalt rock f0und underneath.  On site at in Iceland, there have also been similar efforts on reinject hydrogen sulphide into the ground. Learn more here.