There is great potential for hydropower in Georgia, and this natural resource is likely to be increasingly utilised for power generation in the future. With the escalating demand for energy, government authorities are keen to harness renewable energy from the country’s main rivers. Often these projects aim at remote communities for which connecting to the national power grid is expensive. Hence, local hydropower production is an attractive and sometimes viable option. Critical is to conduct accurate feasibility assessments for hydropower generation at the different potential sites of interest considering climate change impacts. This work is a glacio-hydrological assessment of the expected river discharge at the planned hydropower sites in the Mestiachala river, Georgia.

Based on the requirements of the project, the Spatial Processes in Hydrology (SPHY) cryospheric-hydrological model was selected for the assignment. SPHY is a hydrological model that simulates the runoff at any location within the basin at a daily timescale. SHPY is ideal to assess glacier and snow influence in the river discharge and evaluate the impact of climate change. SPHY was used to predict the river discharge for the extended period of record and provide enhanced flow duration curves for hydropower assessment. In addition, total runoff components were quantified such as snow and glacier runoff.

This glacio-hydrological assessment delivered river discharge estimates for intake locations of two planned runoff river hydropower plants near Mestia, Georgia. The assessment included the calibration of a hydrological model, daily river discharge simulation for an extended period of record (1980-2015), climate change scenarios, and the derived flow duration curves to evaluate the flow operation of hydropower turbines. In addition, total runoff components were quantified such as snow and glacier runoff.

The daily river discharge was simulated at the two intake locations for two future periods (for the end of the concession period and for the end of century period) considering two climate change scenarios (RCP4.5 and RCP8.5). Hydrological model simulations were developed using future precipitation and temperature predictions and future glacier extent predictions. The climate change scenarios provide an evaluation of flow operation uncertainty. The daily flow calculations for the two sites can be used in the hydropower calculations, and to assess the overall profitability of the planned investment, taking into account energy prices, demand, etc.

Indonesia is endowed with a full range of both renewable and fossil resources of energy, actively exploited to feed its growing economy. Emphasis has been on fossil, hydroelectric and geothermal resources rather than wind and solar. PLN (Perusahaan Listrik Negara) is the Indonesian State Electricity Company. It is an Indonesian government-owned corporation which has a monopoly on electricity distribution in Indonesia and generates the majority of the country’s electrical power, producing about 175 TWh annually. Only a small fraction of this originates from hydropower.

Indonesia has five large hydropower plants with a capacity over 250 MW: Cirata on Java (1008 MW), Saguling on Java (701 MW), Tangga on Sumatra (317 MW), Sigura-gura on Sumatra (286 MW), and Pamona on Sulawesi (260 MW). The Indonesian government aims to develop more hydropower with quite a strong focus on small and micro hydropower plants.

Capacity of PLN staff to understand the hydrology related to hydropower electricity generation needs to be enhanced. Also, the knowledge of the potential impact of climate change on hydropower requires additional capacity of PLN’s staff. Especially their ability to understand and judge feasibility studies undertaken by external consultants requires upgrading their level of knowledge. Also staffs’ capacity to understand climate risk assessment studies, as today required by most investors, should be further developed.

FutureWater was asked to develop and provide training on those two aspects (hydrology and climate change). Given the huge area of the country and PLN staff working in large distances from each other, it was decided to provide training in a eLearning setting. Initially about 25 staff will be trained and based on lessons learnt the training package will be adjusted to staff needs and further training will be undertaken.

For the two study catchments, satellite imagery and field observations were combined to perform a land degradation assessment and to identify trends. Secondly, baseline hydrological conditions were assessed using a hydrological simulation model. Future changes in hydrology and hydropower generation were evaluated by running the biophysical model for a Business-as-Usual scenario, accounting for land degradation trends, changes in water use, and climate change.

Subsequently, the impacts of three catchment investment portfolios (low, medium, high) containing different catchment activities were quantified with respect to the BaU scenario. Benefits and costs were analysed for the hydropower developers to evaluate whether it makes sense for them to invest in improved catchment activities. For one of the catchments this is clearly the case (Kiwira, Tanzania).

The analysis shows that the impacts of climate change on revenue from hydropower are in the same order of magnitude as the other negative anthropogenic factors: increased domestic water use demand in the catchment and land degradation due to poor conservation of natural areas and poor agricultural practices.

There is interest to develop run-off river hydropower plants in a watershed in southwestern Georgia: a cascade of two projects of around 25 MW each. Before the actual development phase can start, a hydrological assessment is necessary to assess expected flows at the two locations with higher accuracy than currently available from limited flow measurements.

FutureWater was contracted by the developers to undertake an assessment of the expected daily flows at the two site locations , based on satellite data and hydrological modelling. Only very limited streamflow data were available, so the assessment was based mainly on hydrological modelling of the basin upstream of the points of interest. Principally global datasets were used for the input requirements of the hydrological modelling. Validation of the model was done using limited recent streamflow data available and satellite-based snowcover measurements. The principal output of the work are daily flows and a flow duration curve, based on model simulations. The flow duration curve includes confidence bounds based on the uncertainties that can be expected originating from data and model parameters.

From this hydrological assessment, a number of recommendations are put forward that aim at increasing the level of accuracy in the outcomes and narrow the uncertainty range for the following feasibility stage. Recommendations are done for data improvements, model improvements and field validation.Outcomes of this study will be used by the developer to analyse the hydropower potential and evaluate the economic feasibility.

There is so far no accepted general methodology for assessing the significance of climate risks relative to other risks to water resources projects that the World Bank Group supports and invests in. The Independent Evaluation Group (IEG) in its 2012 report entitled “”Adapting to Climate Change: Assessing the World Bank Group Experience””, found that “climate models have been more useful for setting context than for informing investment and policy choices” and “they often have relatively low value-added for many of the applications described” and that “although hydropower has a long tradition of dealing with climate variability, the Bank Group lacks guidance on appropriate methods for incorporating climate change considerations into project design and appraisal.”

The book “”Confronting Climate Uncertainty in Water Resources Planning and Project Design: The Decision Tree Framework”” by Casey Brown and Patrick Ray was published in 2015. Since then, the Decision Tree Framework (DTF) has been applied to Bank projects facing diverse situations in six pilots covering hydropower, water supply, and irrigation with funding from the Water Partnership Program (WPP). This effort is continuing in two additional pilots with financing from the Korea Green Growth Trust Fund (KGGTF) targeting the resilience component of water security of flood protection and irrigation in the Nzoia River basin in Kenya and the application of the Hydropower Sector Climate Resilience Guidelines (which in turn are based on the DTF) to the Kabeli-A hydroelectric project in Nepal.

Together with partners, FutureWater applies the following bottom-up methodology DTF to the Nzoia irrigation project in Kenya and the Nepal’s Kabeli-A run-of-river hydroelectric project study. FutureWater´s main tasks are assessing risks using crop modeling and water allocation modeling of the Nzoia case study, and hydrological modeling of the high-mountain region in Nepal.

The project should turn this renewable energy opportunity into a source of economic empowerment for the region and a sustainable source of electricity for the people living in North Sumatra. A pre-feasibility study is undertaken to the expected flows at the intake of the proposed Tripa hydro-electric power plant to indicate whether a more detailed feasibility study is feasible.

For the analysis of the expected flow at the intake a hydrological model, called HEC-HMS is used. This hydrological model simulates rainfall-runoff at any point within a watershed given physical characteristics of the watershed. The model is freely available, somewhat less data demanding, and easy to apply. The outputs of the model are analysed by means of streamflow hydrographs, and flow duration curves that serves as a basis for economic feasibility studies to the capacity of the proposed power plants. In addition, flood flows with recurrence intervals up to 10.000 years are analysed.

The energy sector is sensitive to changes in seasonal weather patterns and extremes that can affect the supply of energy, harm transmission capacity, disrupt oil and gas production, and impact the integrity of transmission pipelines and power distribution. Most infrastructure has been built to design codes based on historic climate data and will require rehabilitation, upgrade or replacement in the coming years. This poses both a challenge and an opportunity for adaptation. Central Asia is one of the most vulnerable regions in the world. Expected climate impacts range from increased temperature (across the region), changes in precipitation and snow, greater extreme weather events, aridisation and desertification, health, and changes in water resources.

Energy and water are closely interrelated as water is used to generate energy (hydropower, cooling of thermal plants) but energy is also required to fulfil water needs (e.g. pumping, water treatment, desalination). Especially in Central Asia, meeting daily energy needs depends to a large extent on water. Guaranteeing sufficient water resources for energy production, and appropriately allocating the limited supply, is becoming increasingly difficult. As the region’s population keeps on growing, competing demand for water from other sectors is expected to grow, potentially exacerbating the issue.

Amy_Darya_Syr_Darya_map

The World Bank is committed to working with the governments of Central Asia to undertake analysis and to identify priorities in adaptation to climate change, including strengthening regional trade through a rigorous, transparent region-scale study. Therefore it currently undertakes a regional assessment to identify areas of possible coordination and possible transboundary impact. The overall project objective is to contribute to a better understanding of the challenges and opportunities for effective joint management of climate adaptation, contributing to the objective of the World Bank’s Central Asia strategy of energy and water security through enhanced cooperation. The results of this assessment should guide current and future decision-makers on options for investments in and management of power generation and transmission/distribution assets through enhanced cooperation.

The objective of this study is to support the “Central Asia Regional Energy Sector Vulnerability Study” led by Industrial Economics (IEc) and funded by the World Bank, by carrying out an expanded risk assessment for water availability and water related energy sector impacts in the region. The work will build on the existing tools developed previously for Syr Darya and Amu Darya basins. Various necessary extensions and enhancements of the tools will be made to include the latest understanding of climatological and hydrological processes and include the latest planned investments in hydropower facilities and cooling water abstractions of the thermal power plants in the region.

The climate, cryosphere and hydrology of the Hindu-Kush Himalaya (HKH) region have been changing in the past, and will continue to change in the future; warming of the climate system is unequivocal. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. The Himalayan region has the third largest deposit of ice and snow in the world, after Antarctica and the Arctic and might be exceptionally vulnerable. There is good agreement among Global Climate Models (GCM) on future temperature trends in the region, but projections of future precipitation patterns differ widely. As a consequence, the demand for increased knowledge about future climate change is still high. A main focus has been given to temperature increases and changes to the hydrological cycle with the tendency that wetter regions mainly will become wetter and drier regions will become drier. Growing scientific knowledge and recent weather events show that extremes related to hydrological changes can be substantial though and the geographical and time-wise resolution of predicted changes is still low in many areas.

Energy is one of the major drivers of changes in the HKH region. The region has a high potential for hydropower due to abundance of water in conjunction with verticality of landscape. However, the changing climate and hydrological regime might pose a risk to hydropower development in the future. It has become imperative for hydropower developers to have a good understanding about the changes in the hydrological cycle and its uncertainty. Also, changing probabilities and magnitudes of extreme events can put additional risk on hydropower infrastructures.

Hydropower projects in Nepal according to the Department of Electricity as of 16 March 2015. The Tamakoshi basin is indicated by the blue boundary.
Hydropower projects in Nepal according to the Department of Electricity as of 16 March 2015. The Tamakoshi basin is indicated by the blue boundary.

The overall objective of this project is therefore to improve the understanding of the expected impacts of climate change on water availability in the context of potential hydropower development in the Tamakoshi River Basin. Specifically, the project aims to:

  • Understand the current baseline hydrological regime of the Tamakoshi River Basin
  • Develop detailed climate change projections for the 21st century, including factors relevant for hydropower development
  • To understand the future hydrology and its potential impact on the hydropower potential

Warming of the climate system is unequivocal. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased. The Himalayan region (after Antarctica and the Arctic) has the third largest amount of ice and snow in the world, and is exceptionally vulnerable. The various Global Climate Models (GCM) predict very similar future temperature trends for the region, but projections of future precipitation patterns differ widely. As a consequence, the need for increased knowledge about future climate change remains high. The main focus of GCMs thus far was on temperature increases and potential changes to the hydrological cycle. The overall tendency that has emerged is that wetter regions are likely to become wetter and drier regions drier. Increased scientific knowledge, coupled with recent weather events, show that changes in hydrological extreme events can be substantial and the geographical and temporal resolution of predicted changes remains low in many areas.

For Statkraft, as the largest generator of renewable energy in Europe and a leading company in hydropower internationally, an understanding of future changes to the hydrological cycle and its uncertainty is crucial for effective business planning. Investment decisions regarding the business strategy for the next 50 years depend on accurate predictions of climate change impacts on inflow over that period.  In addition, changing probabilities and magnitudes of extreme events can put additional risk on infrastructure (dams and hydropower plants) or on other crucial infrastructure (roads and transmission lines).  Statkraft’s intention to grow in the region makes it necessary to assess short, medium and long-term impacts, risks and opportunities resulting from climate change, to ensure sustainable management of the water resources for all stakeholders. Currently, Statkraft’s main business focus lies with northern India (mainly the state of Himachal Pradesh) and Nepal, while Bhutan and Myanmar might be areas of future business development as well.

Kaligandaki Hydro power located in Nepal.

Through the International Centre for Integrated Mountain Development (ICIMOD), the inter-governmental learning and knowledge sharing Centre serving the eight regional member countries of the Hindu Kush Himalayas (HKH), FutureWater provided a comprehensive review study on climate change and the impacts on cryosphere, hydrological regimes and glacier lakes in the Indus, Ganges, and Brahmaputra river basins. This review study was done in the context of future hydropower development in the region.