Geothermal power has the potential to make an enormous contribution to a rapid transition to a low-emissions economy. The University of Utah estimates that heat from global geothermal resources is equivalent to 42 million megawatts of power. To give you an idea on what that means in practice, one megawatt can meet the power needs of about 1,000 homes. So here we are talking about the potential of 42 million megawatts – million! – that’s millions of homes powered by geothermal. That’s the scale we need!
But you can't assume that geothermal is always a clean energy source. When we convened our expert committee to set out criteria for geothermal we found not all geothermal is low emission. In fact, some geothermal plants can generate higher direct greenhouse gas (GHG) emissions than fossil fuel equivalents - for example, drilling down through some rock types can lead to fugitive greenhouse gas emissions. Robust criteria for geothermal need to exclude those geothermal projects that have high emissions whilst supporting low emission geothermal.
Earlier this year the Climate Bonds Standard convened two groups to draft criteria for what geothermal power assets would be eligible for Climate Bonds Certification: a Technical Working Group and a Geothermal Expert Advisory Committee.
Geothermal Technical Working group
Akira Tanabe, Senior E&S Specialist, International Finance Corporation (IFC)
Magnus Gehringer, Senior Consultant Geothermal Specialist, IFC
Tom Harding-Newman, Energy Specialist, leading IFC’s geothermal advisory services in Turkey (developing best practices for geothermal exploration)
Kevin McCray, Executive Director, National Groundwater Association (NGWA)
Geothermal Expert Advisory Committee - provided input as technical advisors, however they do not formally endorse the criteria that have been developed
Roland Roesch, Senior Programme Officer, Renewable Energy Markets and Technology Dialogue, International Renewable Energy Agency, IRENA
Ausilio Bauen, Director, E4tech
Adam Chase, Co-Director, E4tech
Eligibility criteria developed by the working group have now been released for a 30-day public consultation period.
The overarching criteria for all eligible geothermal projects is a near zero GHG emissions operating profile.
The objectives of the geothermal eligibility criteria are to:
- Distinguish low-emitting from high-emitting geothermal projects
- Avoid certifying projects which displace other renewables, given that geothermal operational emissions can be far from negligible
- Exclude projects where emissions are poorly understood
- Exclude projects which do not meet acceptable standards in terms of environmental impact, health,safety and induced seismicity (i.e. generating earthquakes)
Following these objectives, eligibility criteria has been developed into a consultation document providing clear guidance.
Eligible projects include:
- New or existing geothermal projects where estimated emissions performances are negligible. The estimation must use a GHG accounting methodology and result in an emissions profile no greater than zero gCO2/kWh (carbon emissions/power generated)
- Technology upgrades to a binary cycle power plant to address fugitive GHG emissions by implementing a closed loop system that returns GHG gases to the existing reservoir.
- Clean Development Mechanism approved project (meaning it is compliant to CDM) and therefore is expected to have negligible emissions (meeting the zero gCO2/kWh threshold).
- All eligible geothermal projects must be compliant with the environmental regulations at the national and local level.
- Projects are also required to comply with one of the international guidelines and standards on environment, health and safety for geothermal power generation (e.g.IFC, World Bank – more details in the consultation document).
The standard also strongly recommends adherence to one of the following Performance Standards on Environmental and Social Sustainability:
- IFC PS5 Land Acquisition and involuntary Resettlement
- IFC PS6 Biodiversity Conservation and Sustainable Management of Living Natural Resources
More details on all the above criteria is available in the full standard consultation document.
After a 30-day consultation period the criteria will be reviewed in the light of feedback received, and the amended criteria, subject to amendments only being minor, will be submitted to the Climate Bond Standards Advisory Board* for confirmation.
The Working Group and Advisory Committee will next examine geothermal heat pumps.
*Disclosure: The Climate Bond Standards Advisory Board is an Advisory Committee to the Climate Bonds Board.