The vulnerability of hydropower production in the Zambezi River Basin to the impacts of climate change and irrigation development

Transcription

1 The vulnerability of hydropower production in the Zambezi River Basin to the impacts of climate change and irrigation development Spalding-Fecher R., Chapman A., Yamba F., Walimwipi H., Kling H., Tembo B., Nyambe I., and Cuamba B. 1

2 Presentation of phase I research results Hydropower in the Zambezi River Basin at risk due to changing climate and increased irrigation Background on research project, process and stakeholder input Modelling approach, assumptions and calibration Key results for existing and new hydropower plants Conclusions 2

3 Background on the research project Objective: assessment of how upstream changes in climate and irrigation demand would affect water availability for major downstream Zambezi Basin hydropower plants. Timeline and process Endorsed by SAPP CC in Sep 2011, and by ESC in Feb 2012 Started early 2012, presentations to ESC in Aug 2012, Feb 2013 Main ZRB utilities all contacted, as well as water and climate authorities Review workshop with ESC members and ZRA in Oct 2013 Final report and model complete, and available on UCT website All outputs also circulated to Project Steering Committee (PSC), chaired by SAPP CC, and including ZRA, SADC Energy, ZAMCOM Interim Secretariat, DfID and CDKN Phase 2 to commence in February,

4 Partnership between three universities, two consulting firms and a research organisation Project Steering Committee SAPP, SADC, ZRA, ZAMCOM, DFID, CDKN Project Administration UCT Research Director Pöyry UCT Poyry OW CEEEZ UEM UNZA Energy data SA Energy Model Research Direction Modelling and Scenario development Integration Development Scenarios Climate and water data Climate scenarios Stakeholder links Zambia climate, water, power data Stakeholder links Moz climate, water, power data Work with project owners Stakeholder links Stakeholder engagement & Review SEI parternship for training and support 4 13 February 2013

5 Outline The vulnerability of hydropower production in the Zambezi River Basin to the impacts of climate change and irrigation development Background on research project, process and stakeholder input Modelling approach, assumptions and calibration Key results for existing and new hydropower plants Conclusions 5

6 Modelling approach SEI s Water Evaluation And Planning (WEAP) tool provides a user-friendly interface and scenario management capability intuitive graphic interface for analysis and presenting results Hydropower plants include: major existing plants (i.e. Kariba, Cahora Bassa and Kafue Gorge Upper) extensions to existing plants (i.e. Kariba North and South bank, Cahora Bassa North Bank) major new plants (i.e. Batoka Gorge, Itezhi-tezhi, Mphanda Nkuwa, Kafue Gorge Lower, and to a lesser extent Boroma and Lupata) Model calibrated against historical measured data at key points along the river (e.g. Victoria Falls) and at key reservoirs (e.g. lake levels at Kariba, discharges at Itehi-tezhi) and demonstrated a strong fit with both historical measurements. 6

7 Schematic of WEAP model with rivers, reservoirs and HPPs 7 $ $ $ $ $ Ð Ð Ð Ð Ð Ð Ð $ $ $ $ $ $ $ $ $ $ $

8 Calibration example: modelled vs gauge flows at Vic Falls 8

9 Calibration example: observed vs modelled volume in Kariba 9

10 Alternative climate and development futures => scenarios First look at climate impact on existing plants (A, B) Then look at impact of climate and new hydropower only (C, D) Then add increasing irrigation demand (E, F) Test for sensitivity to relative priorities of HPP and irrigation (G, H) Test for sensitivity to speed of development (I, J) Hydropower development Irrigation development Future climate A Historical Historical Dry B Historical Historical Wet C Business as Usual Historical Dry D Business as Usual Historical Wet E Business as Usual Business as Usual Dry F Business as Usual Business as Usual Wet G Business as Usual BAU with highest demand priority Dry H Business as Usual BAU with highest demand priority Wet I Optimistic BAU with highest demand priority Dry J Optimistic BAU with highest demand priority Wet 10

11 Outline The vulnerability of hydropower production in the Zambezi River Basin to the impacts of climate change and irrigation development Background on research project, process and stakeholder input Modelling approach, assumptions and calibration Key results for existing and new hydropower plants Conclusions 11

12 Key findings Climate change is the most important overall driver of hydropower potential, but increased irrigation demand has negative impact on downstream plants in Mozambique if prioritised over hydropower Kariba is highly vulnerable to potential future changes is climate and the expansion of Kariba is unlikely to deliver the expected increases in production even under a relatively favourable climate Cahora Bassa s expansion is viable under a wetting climate, but less likely to be realised under a drying climate. Prioritising irrigation demand over hydropower could severely compromise output Batoka Gorge may not be able to reach expected production levels, due in part to other changes in regional water demand and the effect of increasing temperatures across the climate futures Mphanda Nkuwa can deliver the expected production levels under most climate and development scenarios, although production is affected by prioritising irrigation over hydropower 12

13 Climate change is key driver of production at almost all plants Decline in mean annual generation from dry vs wet climate with no increase in irrigation ( ) 13

14 Expansion of Kariba may not deliver as well as HCB expansion, but even HCB vulnerable to increased irrigation demand Mean annual generation as a % of target ( ) NB: Target = historical + planned expansion 14

15 Batoka Gorge may not be able to deliver expected output Annual generation at Batoka Gorge vs target 15

16 Prioritising irrigation has major impact on Mphanda Nkuwa, Lupata, and Kafue Lower Mean annual generation as a % of target ( ) 16

17 Outline The vulnerability of hydropower production in the Zambezi River Basin to the impacts of climate change and irrigation development Background on research project, process and stakeholder input Modelling approach, assumptions and calibration Key results for existing and new hydropower plants Conclusions 17

18 Conclusions Must explicitly consider climate and upstream demand in feasibility studies and overall expansion planning Climate change will make coordinated operation and planning of hydropower plants across countries essential Need to know how climate and upstream demand affect national and regional electricity balance, as well as potential for trade Phase II will address impacts on national and regional systems, by linking water modelling with a regional electricity model 18

19 Climate change, power and water in the Zambezi and SAPP: Phase II Mamahloko Senatla Randall Spalding-Fecher SAPP ESC Meeting, Maputo 26 August 2014

20 Objectives Develop integrated water and power scenarios for the Zambezi River Basin in order to engage stakeholders and inform decision makers through an assessment of potential climate change impacts on water availability and energy security in the Zambezi River Basin and the Southern African power Pool Also includes economic assessment (i.e. social and environmental impacts) of Batoka Gorge 20

21 Integrated analysis supported by training and engagement Capacity building and training SAPP Power Supply Development Futures SAPP Power Demand Integrated Power and Water Scenarios Climate Futures Zambezi Water Demand Zambezi Water Supply Impacts on specific investments and power trade Stakeholder engagement 21

22 Benefits to stakeholders Improving decision making on planning of hydro projects, because of analysis and information base Improve risk management for new hydro projects, which will promote the financing to hydro projects that have stalled Avoiding stranded assets for SAPP utilities and other project owners Support engagement between energy sector and water sector in the region Help electricity sector understand how climate change impacts national energy balances and trade 22

23 THANK YOU! 23

24 Additional slides 24

25 Future annual generation at Kariba 25

26 Future generation at Cahora Bassa 26

27 Future annual generation at Mphanda Nkuwa 27