In consultation with ADB and the project engineers, a rapid climate change assessment for the proposed investment program has been carried out so that the findings of the assessment can be integrated in the project design. The climate assessment focuses on the following issues: (i) screening of natural hazards in the project sites; (ii) simple climate projections focusing on expected temperature increases, extreme precipitations and floods, and extreme heat events; (iii) recommendations for climate change adaptation measures for the electricity distribution system design and operation.
The Asian Development Bank (ADB) is committed to supporting the Uzbekistan Government’s integrated rural economic development initiative that can revitalize the rural economy and help build modern infrastructure and government services in the rural areas. ADB has included targeted programs to provide modern and highly efficient rural infrastructure for power distribution. On these projects, ADB will support the Government’s initiative by means of a result-based lending (RBL) program. One of the key envisioned outputs of the program is to modernize and augment the electricity distribution system. The goal is to start in three provinces: Bukhara, Samarkand and Jizzakh. The proposed project will help Uzbekistan address high technical losses in the power distribution system and improve the electricity supply reliability in the remote areas.
Electricity Transmission and Distribution (T&D) projects are sensitive to climate conditions. Temperature, wind and other variables are typically integrated and considered in the design, as also for this particular project. Thus, changes in these variables due to climate change may affect the performance of the system. Based on these sensitivities, an analysis of climate change projections in the project area (three provinces) was performed, focusing on climate means & extremes (temperature and rainfall) and wind speed trends based on reanalysis (historic) datasets. Overall, the climate model analysis yields following conclusions for the project area:
- Temperature increases by about 2.1 °C (RCP4.5) to 2.7 °C (RCP8.5) are to be expected.
- Extremes related to temperatures (e.g. warm spells, extremely warm days) are likely to increase in frequency and intensity.
- Precipitation totals are likely to stay reasonably constant but the GCMs show a large range of uncertainty under both the RCP 4.5 and RCP 8.5
- Precipitation extremes are likely to increase in frequency and intensity. Maximum 1-day precipitation volumes are expected to increase by about 15% and dry spells are expected to last longer.
Historic trends of wind speed were analyzed for Uzbekistan based on reanalysis data. Based on data over more than a century the data suggests that higher wind speeds (more frequent and/or more intense storms) can be expected in the future.
Considering the type of climate hazards and risks in the project area, and the area-specific climate change projections, overall the most serious threat comes from the expected increase in temperature extremes. Heat related stresses may put significant strain on the electricity system, leading to system faults, reduced power supply and power outages. Dust storms may also occur more frequently due to increased drought conditions, causing transmission losses to overhead power lines and damage transformers and distribution substations. In addition, while the hazard exposure is constricted to smaller parts of the project area, the expected increase in extreme precipitation events may lead to more frequent and powerful flooding events. Flooding and inundation of electricity network infrastructure have major impacts, often causing partial or complete power outages. Higher extreme discharges can also lead to more frequent landslides and more powerful mudflows, posing serious risk of damaging transmission towers which may lead to power outages.
2019 - FutureWater Report 191
TA-9656 UZB: Sustainable Energy Access – Distribution Network Modernization Program – Climate Risk and Vulnerability Assessment