Enhancing the Climate Resilience of African Hydropower and Irrigation Infrastructureawra.org/meetings/Denver2015/doc/PP/powerpoint/Sessi… · · 2015-12-11Resilience of African

Slide 1

Enhancing the Climate Resilience of African

Hydropower and Irrigation Infrastructure

David Groves Zhimin Mao

Robert Lempert

2015 AWRA Annual Meeting Denver, CO

Water and Climate Resilience Center

Slide 2

Work a Part of Recently Completed World Bank Funded Study

1. Continent-wide evaluation of water and energy sectors

2. Water and energy facility scale case studies

Slide 3

Huge Water and Energy Infrastructure Needs Now and Into the Future

• Annual infrastructure investment needs around $80 billion per year

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Large investment projects likely to meet much of the need

Program for Infrastructure Development in Africa (PIDA)

• Hydropower generation (>54 GW)

• Water storage (20,000 km3)

• Irrigation canals

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How Might Climate Change Affect Africa’s Needs and the PIDA Strategy?

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How Might Climate Change Affect Africa’s Needs and the PIDA Strategy?

Potential Change Risk Opportunity Increasing temperatures • Water stress;

higher irrigation needs

Increasing precipitation trends

• Flooding • Higher hydropower production

• Lower irrigation needs

Decreasing precipitation trends

• Lower hydropower production

Increased hydrologic variability

• More severe droughts/flooding

• Lower returns on infrastructure investments

• Higher returns on infrastructure investments

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Developed Integrated Modeling System to Evaluate Climate Impacts on Water and Energy Infrastructure

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Used Robust Decision Making to Structure Vulnerability and Adaptation Analyses

1. Decision Structuring

2. Case Generation

3. Vulnerability Analysis

4. Tradeoff Analysis

Descriptions of key vulnerabilities

Robust Designs

Alternative Designs

www.rand.org/rdmlab

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Applied Framework Across Africa

River Basins Power Pools

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Iterative Analysis Considered Multiple Cases to Isolate Potential Climate Effects

• Investments: PIDA+ •Historical climate Reference Case

• Investments: PIDA+ •Wide range of climate futures (121)

Climate Change, No Adaptation

• Investments: PIDA+ w/ perfect foresight •Representative set of climate futures (6)

Climate Change, Perfect Foresight

• Investments: PIDA+ w/ robust adaptation •Representative set of climate futures (6)

Climate Change, Robust Adaptation

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Wide Range of Climate Effects for Southern Africa Power Pool Basins

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Wide Range of Climate Effects for West African Power Pool Basins

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Significant Negative Impacts Without Adaptation in the South African Power Pool

Hydropower

Irrigation

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Wide Range of Impacts (positive and negative) Without Adaptation in the West African Power Pool

WAPP

Hydropower

Irrigation

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Developed Perfect Foresight Strategies for Specific Climate Futures

• Basin level infrastructure adaptations – Planned turbine capacity – Reservoir storage – Mean conveyance irrigation efficiency

• Farm level adaptations – Planned irrigation area – Use of deficit irrigation – Field-level irrigation efficiency

Adaptation limited to adjustments to planned infrastructure

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Perfect Foresight Adaptation Can Provide Modest Performance Improvement

Zambezi Hydropower

Economic Benefit from Baseline Projects

Economic Benefit from Adaptation

Scaled Net Revenues

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Effects of Adapting in the Wrong Way Are Large

Picking the wrong adaptation Not adapting at all

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By Exploring “Regret” Across Futures, Robust Strategies Are Identified

(PIDA+ or Perfect Foresight)

Strategies with low regret • Range of regret for PIDA+

across futures is always positive

• Implies that PIDA+ is not optimal for any future (including historical conditions)

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By Exploring “Regret” Across Futures, Robust Strategies Are Identified

(PIDA+ or Perfect Foresight)

Strategies with low regret

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Savings from Robust Adaptation Could be Significant In Some Basins

(SAPP) (SAPP) (WAPP) (WAPP) (WAPP) (EAPP)

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Costs of Adaptation Are Generally Modest

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Summary of Key Findings

• Africa-wide study identified significant potential climate change impacts to the water and power sectors

• Adjusting infrastructure plans can improve performance in climate change futures

• Uncertainty about future climate makes potential regret significant

• Identified robust adaptations can reduce regret and improve outcomes

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Limitations and Possible Extensions

• Analysis focuses on large infrastructure

• Small and distributed infrastructure may be: – Less vulnerable to climate – More adaptable and thus have lower

regrets

• Plausible climate futures derived from downscaled global climate models only – May underestimate effects of variability

Water and Climate Resilience Center www.rand.org/jie/centers/water-climate-resilience.html Project Report: http://goo.gl/2iAX4C David Groves [email protected]

http://www.rand.org/jie/centers/water-climate-resilience.html

http://goo.gl/2iAX4C

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Study Evaluated Five Diverse Water and Energy Projects Across Africa

1. Lower Fufu Hydropower Project (Zambezi River Basin, Malawi)

2. Batoka Gorge (Zambezi River Basin, Zambia)

3. Mwache Dam (Kwale District, Kenya)

4. Polihali (Orange River Basin, Lesotho)

5. Pwalugu (Volta River Basin, Ghana)

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Case Study Projects Face Different Possible Future Climate Conditions

Annual cycle of precipitation

Interannual variability of precipitation

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Case Studies Used DMUU Methods to Evaluate Vulnerabilities and Design Robust Alternatives


2. Case Generation




Robust Designs

Robust Decision Making (RDM)

Alternative Designs

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Case Studies Demonstrate Approach That Could Be Applied in Feasibility Design Stage

• Case Studies: – Use data from pre-feasibility reports – Based on limited interaction with host country – Use models that were externally validated only

• Results are illustrative

Methodology can be applied by feasibility study team to ensure climate

resilience of final project

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This Talk Focuses on the Batoka Gorge Case Study

• Zambezi River

• 181 meter-high dam; 1,680 million m3 storage

• Two power stations – Eight turbines – 1600 MW capacity

• Baseload and peaking capacity benefits – Zambia – Zimbabwe

Does Considering Climate Change Suggest an Alternative Project Design?

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Each Case Study Focused on Key Uncertainties, Adaptation Options, and Performance Metrics


2. Case Generation




Robust Designs

Alternative Designs

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How Would Each Project Perform Under Different Plausible Futures?

• Climate change

Batoka

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• Irrigation and urban demands

Pwalugu

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• Project Benefit Factors – Power purchase agreements – Price for delivered water

• Project Costs – Penalties for under-production or delivery – Irrigation area expansion

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Alternative Infrastructure Designs

Considered

• Facility size (dam height and storage capacity)

• Facility capacity (turbines, transfer volumes)

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Alternative Designs Compared by Net Present Value

• Benefits – Hydropower production – Irrigation water supply – Volumes of water transferred

• Costs – Capital and O&M costs – Under-performance penalties

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Analyses Use DMUU Methods to Evaluate Vulnerabilities and Design Robust Projects


2. Case Generation




Robust Designs

Alternative Designs

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Alternative Batoka Gorge Designs Proposed and Costed

35 alternative designs

– 5 dam heights /reservoir storage sizes

– 7 turbine flow capacities

Design cost tool – Estimate capital

and O&M costs for alternative project designs

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Alternative Designs Simulated Across Hundreds of Plausible Futures

• Water management model (WEAP) – Estimate runoff from

climate data – Simulate operations of

alternative project designs

– Capture other system constraints (inflow requirements, other demands)

Slide 39

Analyses Use DMUU Methods to Evaluate Vulnerabilities of Alternative Designs


2. Case Generation




Robust Designs

Alternative Designs

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We First Identified the Historical Optimal Batoka Design for Reference…

• Highest NPV for historical climate conditions

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Then We Evaluated the Vulnerability of this Design to Other Futures

• 145 different climate futures

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Tradeoff Analysis Helps Compare and Identify Robust Designs


2. Case Generation




Robust Designs

Alternatives Designs

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Different Criteria Used to Measure Robustness

1. Minimize maximum regret

2. Satisfice or a wide range of future conditions

3. Satisfice over a wide range of likelihoods for future conditions

Net Present Value Regret: • Difference between NPV for a particular

design and the best performing design

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Batoka Design Minimizing Maximum Regret Depends Upon the Power Purchase Agreement

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Satisficing Batoka Design Depends on the Expected Flow and Power Purchase Agreement

Historical Optimal Design

Increased Capacity

Smaller Size & Decreased Capacity

Decreased Capacity


$1 billion regret threshold

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Satisficing Batoka Design Depends on the Expected Flow and Power Purchase Agreement


Increased Capacity

Smaller Size & Decreased Capacity

Decreased Capacity

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What Next?

• Use visualizations to support stakeholder and decision maker deliberation over tradeoffs

OR

• Develop new approaches to mitigate residual uncertainty

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In Conclusion: Across All Case Studies We Find…

• Performance of project designs can be sensitive to future climate

• Adaptation can reduce maximum regrets

Improvements in the most favorable futures

Improvements in the least favorable futures

Slide 49

… and Robust Infrastructure Designs

• Are often smaller than the best design for the historical climate

• May be robust over a wide range of climate futures if paired with flexibility in the choice of water or power contracts

Look for the Final Report to be released in the coming months by the World Bank…..

Enhancing the Climate Resilience of African Hydropower and Irrigation Infrastructureawra.org/meetings/Denver2015/doc/PP/powerpoint/Sessi… · · 2015-12-11Resilience of African

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