Green House Gas Emissions Modeling Workshop Summary Report

Abstract

The workshop’s first day of activities involved presentations covering a wide array of topics and concerns. Initial discourse focused on the role of GHG emissions in hydropower and recent reports and publicity concerning the topic. These background discussions set the stage for targeted discussion on the current state of hydro GHG emissions modeling, including representation in international forums (International Energy Agency Annex XII and Intergovernmental Panel on Climate Change) modeling efforts by various organizations Oak Ridge National Laboratory (ORNL), Centro de Pesquisas de Energia Elétrica (CEPEL), and Électricité de France (EDF) and methods for effective policy and implementation (Finnish Forest Research Institute, International Hydropower Association, and Electric Power Research Institute). Further presentations and discussions focused on current and future monitoring programs and considerations for GHG emissions modeling. Later discussion focused on the approach to Volume II of the guidelines document and specific considerations that need to be agreed upon and implemented. The second day of the workshop focused on refining the scope of the guidelines based on the specific sessions covered the previous day. The backbone of GHG emissions modeling should be to implement the net GHG emissions approach, that is, the change in GHG balances of the catchment in post minus pre impoundment conditions. The net emissions approach has been described in detail in the IEA Guidelines Volume I. Issues related to the new guidelines’ clarity, complexity, and audiences were discussed, as were site screening, model quality assurance/quality control, and guidelines dissemination. Additional exchange was held regarding modeling net GHG emissions at reservoirs, estimating pre-impoundment emissions, and modeling post-impoundment emissions. The third day of activities involved a site visit to Norris Dam, one of TVA’s first operating hydropower facilities in the East Tennessee area. The site visit was divided into two sessions: a morning visit to the dam site and an afternoon visit to TVA headquarters, which included presentations on TVA’s integrated system and a visit to the river operations scheduling center. Based on comments received during the workshop, the workshop was largely seen as productive, with major issues being dealt with, model credibility held paramount, and the path forward viewed with confidence. From a “big picture” view, the GHG modeling process should not be so lengthy as to unnecessarily delay reservoir construction. The GHG issue is considered insignificant at a majority of reservoir sites such that proper screening can prove beneficial. Screening tools are under development in an IHA and IEA cooperation, and further collaboration at this workshop provided a clearer path toward effective implementation. Given the future of energy demand, hydrologic variability, climate change, and policy enforcement, the work conducted through this workshop was timely and helps expedite the process of guidelines development. Under the guidance of the technical coordinator and operating agent from CEPEL, Dr. Jorge Machao Damazio, a small team of authors will develop volume II of the guidelines, with Dr. Alm Jukka as the designated lead editor of the Greenhouse Gas (GHG) Emissions Modeling Volume II Guidelines Report.