Assessing Future Water Demand and Associated Energy Input with Plausible Scenarios for Water Service Providers (WSPs) in Sub-Saharan Africa

Pauline Macharia,Nzula Kitaka,Paul Yillia,Norbert Kreuzinger

doi:10.3390/en14082169

Pauline Macharia, Nzula Kitaka + Show 2 more

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https://doi.org/10.3390/en14082169

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Abstract

This study examined the current state of water demand and associated energy input for water supply against a projected increase in water demand in sub-Saharan Africa. Three plausible scenarios, namely, Current State Extends (CSE), Current State Improves (CSI) and Current State Deteriorates (CSD) were developed and applied using nine quantifiable indicators for water demand projections and the associated impact on energy input for water supply for five Water Service Providers (WSPs) in Kenya to demonstrate the feasibility of the approach based on real data in sub-Saharan Africa. Currently, the daily per capita water-use in the service area of four of the five WSPs was below minimum daily requirement of 50 L/p/d. Further, non-revenue water losses were up to three times higher than the regulated benchmark (range 26–63%). Calculations showed a leakage reduction potential of up to 70% and energy savings of up to 12 MWh/a. The projected water demand is expected to increase by at least twelve times the current demand to achieve universal coverage and an average daily per capita consumption of 120 L/p/d for the urban population by 2030. Consequently, the energy input could increase almost twelve-folds with the CSI scenario or up to fifty-folds with the CSE scenario for WSPs where desalination or additional groundwater abstraction is proposed. The approach used can be applied for other WSPs which are experiencing a similar evolution of their water supply and demand drivers in sub-Saharan Africa. WSPs in the sub-region should explore aggressive strategies to jointly address persistent water losses and associated energy input. This would reduce the current water supply-demand gap and minimize the energy input that will be associated with exploring additional water sources that are typically energy intensive.

Highlights

Energy is a major input and cost factor for water supply
The urban population is expected to accelerate in all Water Service Providers (WSPs), except for WSP5 where about 66% of the population within its service area are projected to live in urban areas compared to WSP3, for example, where over 90% of the population in the service area will be urban
In light of the global and regional efforts to accelerate universal water service coverage in sufficient amounts to meet the daily per capita water needs within this decade, there is a need for WSPs to plan well for the projected increase in water demand to address the anticipated increase in the water supply-demand gap and the energy input associated with water supply amidst unpredictable energy prices

Summary

Introduction

Energy is a major input and cost factor for water supply. It effects the operational costs recovery of water supply and the ability of Water Services Providers (WSPs) to extend and deliver quality water services [1]. Energy requirement for water supply is influenced mainly by the operational efficiency of water supply infrastructure, type of raw water input, climate, topographical features, and water consumption patterns [3]. Undertaking energy efficiency measures provides opportunities for WSPs to manage operational costs and enhance operational sustainability through a systematic reduction in energy costs without compromising on the quality of service delivered [4]

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