海水淡化与回用的治理与经济学第3卷（英）

VOLUME3Evaluating Economic Viability Using About the Global Department for Water The World Bank Group’s Global Department for Water brings together financing,knowledge, and implementation in one platform. By combining the Bank’s global Please visit us atwww.worldbank.org/wateror follow us on X:@WorldBankWater. About GWSP This publication received the support of the Global Water Security & SanitationPartnership (GWSP). GWSP is a multidonor trust fund administered by the World Bank’sGlobal Department for Water and supported by Australia’s Department of ForeignAffairs and Trade; Austria’s Federal Ministry of Finance; Denmark’s Ministry of Foreign Please visit us atwww.worldbank.org/gwspor follow us on X:@TheGwsp. About PPIAF The Public–Private Infrastructure Advisory Facility (PPIAF) helps developing-countrygovernments strengthen policies, regulations, and institutions that enable sustainableinfrastructure with private-sector participation. As part of these efforts, PPIAF promotesknowledge-transfer by capturing lessons while funding research and tools availableon its knowledge platform—the Global Infrastructure Hub; builds capacity to scale Please visit us athttps://www.ppiaf.org/or follow us on X:@PPIAF_PPP. About PROBLUE PROBLUE is a multidonor trust fund housed at the World Bank that supports thedevelopment of integrated, sustainable and healthy marine and coastal resources.PROBLUE contributes to the implementation of Sustainable Development Goal 14 and Please visit us athttps://www.worldbank.org/en/programs/problue. Governance andEconomics of VOLUMEEvaluating Economic Viability UsingModern Portfolio Theory June 2025 © 2025 International Bank for Reconstruction and Development / The World Bank1818 H Street NW, Washington, DC 20433 This work is a product of the staff of The World Bank with external contributions. The findings, interpretations,and conclusions expressed in this work do not necessarily reflect the views of The World Bank, its Board of The World Bank does not guarantee the accuracy, completeness, or currency of the data included in thiswork and does not assume responsibility for any errors, omissions, or discrepancies in the information, orliability with respect to the use of or failure to use the information, methods, processes, or conclusions setforth. The boundaries, colors, denominations, links/footnotes and other information shown in this work do Nothing herein shall constitute or be construed or considered to be a limitation upon or waiver of theprivileges and immunities of The World Bank, all of which are specifically reserved. Rights and Permissions The material in this work is subject to copyright. Because The World Bank encourages dissemination of itsknowledge, this work may be reproduced, in whole or in part, for noncommercial purposes as long as full Please cite the work as follows: World Bank. 2025. “Governance and Economics of Desalination and Reuse:Volume 3. Evaluating Economic Viability Using Modern Portfolio Theory.” World Bank, Washington, DC. Any queries on rights and licenses, including subsidiary rights, should be addressed to World BankPublications, The World Bank Group, 1818 H Street NW, Washington, DC 20433, USA; fax: 202-522-2625; Cover design:Circle Graphics. Cover photos:© Adobe Stock. Used with permission of Adobe Stock. Further permission required for reuse. Contents Acknowledgments Abbreviations 1.About This Volume12.Modern Portfolio Theory: What Is It and How Is It Relevant for Water?53.What Is the Simulation and Portfolio Optimization Tool104.Calculating the Economic Levelized Cost of Water of Alternative Portfolios125.Determining the Volumes of Water to Be Dispatched by the Portfolio146.Analyzing Financial and Economic Costs of Different Bulk Water SupplyAlternatives177.Estimating the Reliability and Correlation of the DifferentComponents of the Portfolio218.Estimating the Economic Value of Water and Determining theAffordability of the Targeted Reliability Level24 9.Simulation and Portfolio Optimization Using SPOT27 9.1.Cover and Guide Spreadsheets279.2.Water Resources Data and January Spreadsheets289.3.LCOW Estimation Spreadsheet299.4.Inputs Spreadsheet309.5.Generate Portfolio One Spreadsheet309.6.Annual Portfolio Assessment Spreadsheet339.7.SPOT Spreadsheet35 37 References BOXES 2.1.Constant-Reliability-Benefit Unit Costs—Sample Illustration6.1.Subsidies and Fiscal Impact of the Water Sector and Desalinated Water Production19 FIGURES 1.1.Development Questions that World Bank’s Desalination and ReuseGovernance Guidelines and Tools Are Trying to Answer2.1.Comparison of Probability Density Functions for MinimumStreamflow in the Tana River3.1.SPOT Analysis Framework3.2.Stylized SPOT Portfolio Plotting5.1.Stylized Demand and Supply Growth Curves7.1.Overview of CLIRUN-II Streamflow Model8.1.Water Valuation Approaches and Methods9.1.Overview of SPOT Model Flow Acknowledgments This series of reports was led by Zael G. Sanz Uriarte