ENGURI HYDRO POWER PLANT ISSUES AND PRIORITIES FOR ENERGY SECURITY AND RELIABILITY

The project includes one of the highest arch dams in the world, along with underground structures and substantial electro-mechanical works. The plant is owned and managed by LTD "Engurhesi", a state-owned company, and operates the downstream facilities at Vardnili 1, Vardnili 2, 3, and 4. The project operation and maintenance are complicated by the geo-political situation of the Enguri and Vardnili HPP cascade. The Enguri powerhouse and the downstream facilities are located in the Abkhazia Region, which remains an occupied area and is subject to an administrative border. This complicated situation hinders the effective functioning of the dam as well as major maintenance, repairs, and upgrades. Enguri HPP has suffered from construction and equipment issues from the very onset and has seen minor repairs and maintenance in the late 1980s and 1990s. Substantial rehabilitation has been financed by the European Bank for Reconstruction and Development (EBRD) and partner donors as well as the Government of Georgia (GoG). These efforts began in 1997 when studies revealed the need for critical works. Currently, there is a "Phase IV" program, which is considered the final effort of outside financial support by the EBRD. The Phase IV program is underway and will be completed in the 2020-2021 timeframe, depending on the contractors' schedules and remaining subject to a bid. The stakeholders are aware that major works cannot be completed within the Phase IV. The main objective of this evaluation and report is to identify and prioritize the remaining and anticipated works for the Enguri HPP, following the completion of the Phase IV. The evaluation included a site visit, review of relevant materials, interviews, and discussions with Enguri HPP management. During the site visit, the team assembled a list of issues to be addressed post-Phase IV. These topics incorporated vital tasks identified both by the Program and by Enguri HPP management. While the list cannot include all potential repairs needed in the future of a very complex project, it comprised the most crucial tasks identified by the team. The Enguri HPP and Vardnili cascade are complex facilities operating in a complicated environment, and addressing these issues will be essential for ensuring the long-term reliability and security of the plant. The evaluation identified several priorities for further Enguri HPP security and reliability. Priority 1 includes meeting dam safety criteria, flood analysis and planning, and addressing issues related to the powerhouse and switchyard. Priority 2 involves replacing critical equipment, including penstock valves, generator breakers, and circuit breakers. Priority 3 includes addressing interior powerhouse leakage, turbine gate operation servomotors, and replacing circuit breakers and current transformers. Priority 4 involves ongoing sediment removal, and Priority 5 includes reservoir debris removal, unit flow measurement, spillway gate upgrade, and rebuilding Vardnili 2, 3, and 4. The stakeholders are aware that addressing these priorities will require significant investment and resources. However, ensuring the long-term reliability and security of the Enguri HPP is essential for the Georgian Power Grid and the country's energy security. The evaluation and report provide a comprehensive assessment of the issues and priorities for the Enguri HPP, and will serve as a valuable resource for stakeholders and decision-makers.