Climate

High-temperature geothermal areas in Iceland are all closely linked to active volcanoes, most of which are located along the tectonic plate boundaries that run through Iceland. The heat that rises to the surface comes from shallow magma intrusions or magma chambers. As these intrusions cool, volcanic gases are released, most of which rise towards the surface as they are lighter than water. Some of these gases react with the geothermal water in the system or with the surrounding rock, precipitating as mineral deposits. 

The volcanic gases are mostly carbon dioxide (CO2) or hydrogen sulfide (H2S), but also include small amounts of hydrogen (H2), nitrogen (N2), and methane (CH4). A large portion of these gases are greenhouse gases, including CO2. CO2 partially dissolves when it comes into contact with geothermal water; if the water is supersaturated with carbonate minerals, CO2 tends to react with minerals from the rock and can form calcite deposits (CaCO3). It can also be carried out of the geothermal system with runoff (e.g., groundwater) or rise to the surface through fractures or soil where the rock is porous, as is often the case in Icelandic geothermal areas. A conceptual model for the origin and ascent of CO2 through volcanic high-temperature systems can be seen in Figure 1. 

The emission of gases in geothermal areas, especially CO2, varies depending on the activity of the areas and their tectonic structure. For example, the seismic activity that has occurred on the Reykjanes Peninsula in recent years has affected the tectonic structure of HS Orka’s production areas, where a large number of new fractures have formed, providing an easy path for gases to reach the surface. 

Measurements of gas emissions at the surface of geothermal areas have changed little over the past 20 years. External factors can skew these measurements, such as weather conditions, making it important to take measurements under appropriate weather conditions. Another factor that can skew measurements is the location of the emissions, as it is difficult to estimate where on the geothermal area the emissions occur. In geothermal areas with significant seismic activity, fractures can form, creating easier paths for gases to reach the surface, potentially releasing a substantial amount of gases in a short period. This makes it difficult to measure these emissions. 

Geothermal production involves the release of greenhouse gases already present in the system, as described above. Boreholes penetrate various depths into the system, releasing steam and water along with the gases present in the system. The volcanic gases travel through the production system of geothermal power plants and into the atmosphere.  

The published emission intensity of HS Orka (i.e., the emission of greenhouse gases per unit of energy produced) assumes that all direct emissions from the company’s geothermal power plants are anthropogenic, at least until research indicates otherwise. The company assesses the emission intensity of its operations based on the annual emission of greenhouse gases in scopes 1, 2, and 3, and the produced electricity and sold heat. 

HS Orka has committed to reduce the company's emissions intensity by 40% by 2030 (compared to 2014). It amounts to a goal of reducing emissions to 26 g of CO2 per kilowatt-hour of electricity produced and heat sold. In 2023 HS Orka’s emissions intensity was 25 gCO2eq/kWh. 

Additionally, HS Orka completed life cycle assessments for the Svartsengi and Reykjanes power plants in 2023, the results of which show the emission intensity over the decades-long lifespan of these plants. The emission intensity of Svartsengi was estimated at 43.5 gCO2eq/kWh, while that of Reykjanes was 17.1 gCO2eq/kWh. 

In the classification regulation of the European Union (EU Taxonomy), emissions must not exceed 100 gCO2eq/kWh for an investment in energy to be considered a sustainable investment. 

HS Orka is working to integrate its commitment to carbon neutrality in 2040 with development projects aimed at utilizing the company's CO2 emissions. The biggest projects concern the production of electric fuel. Alongside the development of those projects HS Orka will continue to explore the feasibility of other options to ensure that the goal of carbon neutrality is achieved. 

Various regulations have been implemented in recent years with the aim of achieving real progress in climate issues. Most regulations are developed in collaboration with European countries, but their implementation in Iceland is the responsibility of Icelandic authorities. Geothermal energy is little known in most parts of Europe and nowhere as significant as in Iceland. Thus, a unique situation and discrepancy regarding CO2 from geothermal energy have gradually emerged: 

• Iceland is the only European country known to classify CO2 from geothermal energy as entirely anthropogenic in its national carbon accounting (ESR). 
• Additionally, the EU last year adopted a regulation on renewable fuels of non-biological origin, stating that carbon dioxide from geothermal power plants is not deductible in their emission accounting if it is utilized in the production of renewable fuels, unless it can be shown that the carbon dioxide was previously released naturally. As described above, proving this is challenging. 

This also creates contradictions within and between regulations: