Carbon dioxide emission intensity

Carbon dioxide emission intensity is defined as the level of emissions, relative to each operating unit, e.g. unit of produced energy, income, and other indicators relevant to the operation.

ON Power produces electricity for consumers, as well as hot water, which is sold wholesale to Veitur Utilities. Carbon emissions per unit of electricity and hot water at ON Power Plants have decreased since 2015, and are now 7.4 g of CO₂ equivalents per kWh. Proportionate reinjection of carbon dioxide at the Hellisheidi Geothermal Power Plant was approximately 30% in 2021. Operations at Hellisheidi and Nesjavellir Geothermal Power Plants are carried out under a scheme that aims for a zero carbon footprint in 2025 and 2030, respectively. This means that 95% of the carbon dioxide emitted from the power plants, will either be captured and stored, or utilised.

It should be noted that the emissions uncertainty is +/- 12% compared to the 95% uncertainty range.

Veitur Utilities distribute electricity and hot water to consumers, process and distribute potable water, as well as managing the sewerage systems. Veitur Utilities' water utility, district heating, electricity utility, and sewerage systems have reduced their carbon emissions since 2015.

Reykjavik Fibre Network's data transmission has increased its carbon emissions per unit data transmission due to construction work.

Reykjavik Energy Group's activities do not emit any ozone depleting substances.

*Carbon footprint of low-temperature geothermal fields has been rated as approximately 0 g/kWh.

Hydrogen supphide emission intensity

The hydrogen sulphide emission intensity from one unit of produced electricity per kWh at the Hellisheidi Power Plant has been reduced since 2015, or from 6 g per KWh to approximately 1 g, and at the Nesjavellir Power Plant from 4 g per kWh to approximately 2 g.

The concentration of hydrogen sulphide ( H₂S) in populated areas did not exceed limits 2021. The result of systematic cleaning and reinjection of hydrogen sulphide from the Hellisheidi Geothermal Power Plant in 2021 increased from 2020. Proportionate reinjection of hydrogen sulphide from the plant was approximately 80%, which is a little less than previously planned, as the hydrogen sulphide abatement unit at the plant had to be adjourned for a prolonged period, due to unforeseen malfunctions.

Hydrogen sulphide emissions from Nesjavellir and Hellisheidi Geothermal Power Plants amounted to 8.3 thousand tonnes in 2021. Operation activities at the power plants at Hellisheidi and Nesjavellir are in accordance with the objective of a light carbon footprint by 2025 and 2030, respectively. Thus, almost all hydrogen sulphide from the power plants will be captured and stored in basaltic rock.

It should be noted that the emissions uncertainty is +/- 12% compared to the 95% uncertainty range.

Maximum injection of carbon dioxide and hydrogen sulphide since 2014

In 2021, the combined injection of carbon dioxide and hydrogen sulphide from the Hellisheidi Geothermal Power Plant was 20,800 tons and exceeded the maximum amount injected since 2014.