Subject: Comments to Draft Specifications for Application of UNFC-2009 to Geothermal Energy Resources: from the Expert Group on Resource Classification (EGRC) Solar Working Group
4 August 2016
The Solar Working Group wants to congratulate the Geothermal Working Group for the great work it has done and for leading the way when it comes to preparing specifications for specific types of renewable energy. The Solar Working Group reviewed the Geothermal Specifications: in solidarity with a fellow Group under the Task Force; to better understand what is to be included in such specifications; and, to help ensure there is consistency in the application and description of the EFG axes, as well as presentation of case studies. While reviewing the Geothermal Specifications several ideas, observations and questions occurred to the Group, hence we have drafted the text below as feedback.
We found the document to be well constructed, clearly setting out how to classify geothermal resource estimates. In particular, we found the case studies to be very useful and nicely illustrated how the guidelines could be applied to actual projects.
The introduction noted that the Geothermal Specifications were to be used in conjunction with the Renewables Specifications and the UNFC-2009. However, the Geothermal Specifications seem adequate for use as a standalone document. How do you envisage people classifying geothermal energy using the Geothermal Specifications in conjunction with the Renewables Specifications and UNFC-2009?
There is a question as to whether direct use of geothermal heat was counted. For example, in New Zealand some geothermal energy is used directly to heat treat wood. In the Netherlands some low heat geothermal energy is used to keep greenhouses warm. The direct use of heat may be important in solar as well, as it can substitute other forms of energy used for heating.
The definitions and concepts provided were very useful and are very helpful for the Solar Working Group and its work on Solar Specifications.
Whilst the E and F axis have some explanation that can guide the user, it was felt that the G axis has limited description for the geothermal energy. As in oil and gas, there is some uncertainty in the geothermal resource quantification however clear guidelines (such as PRMS from the SPE) and acceptable approaches are available in oil and gas so that the quantification and classification of resources is not user dependent and subjectivity is taken out of the process.
There is a question as to whether geological guidelines are widely used in the geothermal industry. There are classifications available in Australia* and the United States**. However, it might be useful to have additional information within this document on how to apply the G axis, allowing users to make good use of this classification process. It might also be useful for bridging documents to be prepared, showing how the Australian* and United States standards** correlate to the UNFC and the Geothermal Specifications.
The case studies definitely will help users to understand how to classify the resources in G1, G2, and G3 however not all of the examples are as detailed as others. Additional information for some of the case studies could be beneficial.
On the question of applying the Geothermal Specifications, it might be possible to apply the Specifications to the US geothermal resource assessments from 1975^, 1978^^ and 2008^^^. While these are not projects specific assessments, they are of public policy interest and would demonstrate the applicability of the Geothermal Specifications to official statistics and resource assessments coming out of government. Furthermore, it would demonstrate the applicability of UNFC within the System of Environmental Economic Accounting (SEEA), which includes national physical stocks.
Thank you again for the opportunity to review the Geothermal Specification. The Solar Working Group will be grateful for any response to the feedback above.
Comments from EGRC Solar Working Group to Draft Specifications for Application of UNFC-2009 to Geothermal Energy Resources.
4 August 2016
The Solar Working Group wants to congratulate the Geothermal Working Group for the great work it has done and for leading the way when it comes to preparing specifications for specific types of renewable energy. The Solar Working Group reviewed the Geothermal Specifications: in solidarity with a fellow Group under the Task Force; to better understand what is to be included in such specifications; and, to help ensure there is consistency in the application and description of the EFG axes, as well as presentation of case studies. While reviewing the Geothermal Specifications several ideas, observations and questions occurred to the Group, hence we have drafted the text below as feedback.
We found the document to be well constructed, clearly setting out how to classify geothermal resource estimates. In particular, we found the case studies to be very useful and nicely illustrated how the guidelines could be applied to actual projects.
The introduction noted that the Geothermal Specifications were to be used in conjunction with the Renewables Specifications and the UNFC-2009. However, the Geothermal Specifications seem adequate for use as a standalone document. How do you envisage people classifying geothermal energy using the Geothermal Specifications in conjunction with the Renewables Specifications and UNFC-2009?
There is a question as to whether direct use of geothermal heat was counted. For example, in New Zealand some geothermal energy is used directly to heat treat wood. In the Netherlands some low heat geothermal energy is used to keep greenhouses warm. The direct use of heat may be important in solar as well, as it can substitute other forms of energy used for heating.
The definitions and concepts provided were very useful and are very helpful for the Solar Working Group and its work on Solar Specifications.
Whilst the E and F axis have some explanation that can guide the user, it was felt that the G axis has limited description for the geothermal energy. As in oil and gas, there is some uncertainty in the geothermal resource quantification however clear guidelines (such as PRMS from the SPE) and acceptable approaches are available in oil and gas so that the quantification and classification of resources is not user dependent and subjectivity is taken out of the process.
There is a question as to whether geological guidelines are widely used in the geothermal industry. There are classifications available in Australia* and the United States**. However, it might be useful to have additional information within this document on how to apply the G axis, allowing users to make good use of this classification process. It might also be useful for bridging documents to be prepared, showing how the Australian* and United States standards** correlate to the UNFC and the Geothermal Specifications.
The case studies definitely will help users to understand how to classify the resources in G1, G2, and G3 however not all of the examples are as detailed as others. Additional information for some of the case studies could be beneficial.
On the question of applying the Geothermal Specifications, it might be possible to apply the Specifications to the US geothermal resource assessments from 1975^, 1978^^ and 2008^^^. While these are not projects specific assessments, they are of public policy interest and would demonstrate the applicability of the Geothermal Specifications to official statistics and resource assessments coming out of government. Furthermore, it would demonstrate the applicability of UNFC within the System of Environmental Economic Accounting (SEEA), which includes national physical stocks.
^ White, D.E. and Williams, D.L., 1975. Assessment of geothermal resources of the United States—1975 (No. USGS-75-726). Geological Survey Circular, Arlington, VA. Online: 04/08/2016: http://pubs.usgs.gov/circ/1975/0726/report.pdf
^^Muffler, L.P., 1979. Assessment of geothermal resources of the United States, 1978 (No. USGS-CIRC-790). Geological Survey, Reston, VA (USA). Geologic Div. Online 04/08/2016: http://pubs.usgs.gov/circ/1979/0790/report.pdf
^^ Williams, C.F., Reed, M.J., Mariner, R.H., DeAngelo, J. and Galanis, S.P., 2008. Assessment of moderate-and high-temperature geothermal resources of the United States (No. 2008-3082). Geological Survey (US). Online 04/08/2016: http://pubs.usgs.gov/fs/2008/3082/pdf/fs2008-3082.pdf
Thank you again for the opportunity to review the Geothermal Specification. The Solar Working Group will be grateful for any response to the feedback above.
Comments from EGRC Solar Working Group to Draft Specifications for Application of UNFC-2009 to Geothermal Energy Resources.