In cooperation with

Industry partners

Small-scale Solar-driven Desalination in Namibia

4 Pilot Plants in the villages Amarika and Akutsima

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Implementation Sites

•Groundwater desalination•Subsurface water storage

•Sanitation & reuse •Rainwater harvesting

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adaptedsanitation &waste watertreatment

multi-resource mix

•gardening •health•water re-use•job creation

•gardening

•Improve livelihoods of the people through innovative water supply andwaste water treatment technologies adapted to regional conditions

(economic, ecological, social)

support and framing

knowledgemanagement

empiricalstudies

participation governance & institutions

capacitydevelopment

rainwaterharvesting

decentralisedgroundwaterdesalination

subsurfacewater storage

Project Approach

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Saline Groundwater

Processing and cartography: Mendelsohn 2011

Data source: Bittner Water Consult, Windhoek

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Why Solar-driven Desalination?

only saline groundwater available

produce fresh water with high quality for drinking water purposes

high solar radiation in northern Namibia (> 6 kWh/(m²d))

remote areas and therefore restricted availability of other(conventional) energy sources like diesel or gas

reduce environmental impacts (no greenhouse gas (CO2) emitted), since desalination has always a high energy demand

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Benefitsbefore after

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Benefits

traditional water sources (hand dug wells)

are contaminated by algae, faeces and parasites

the salinity increases during the dry period

available water quantity depends on the last rainy season

desalination

produces fresh water with high chemical quality (class A for destillate, class B for permeate) and low bacteriological contents

fresh water quality is constant throughout the year

fresh water quantity is independent from seasonal fluctuations

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O&M Concept

local caretakers and guards from the villagesprotect and take care of the plants on a dailybasis

a service provider (Aqua Services & Engineering, ASE) visits the plants regularly(~every two months) for maintenance, repairsand water analysis

via data transmission (satellite connection) themanufacturer of the plants can monitor theplants from Germany. This helps to detectmalfunctions early and to plan service trips

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O&M Concept

a Water Point Committee(WPC) is elected fromthe village people

the WPC is responsiblefor the plant especiallydistribution and waterselling (accounting)

the WPC needs muchsupport from DWSSC

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Challenge: O&M in remote areas

no tarred roads or gravelroads to the sites(difficult especially duringthe rainy season)

no network

low education level oflocal caretakers

no highly qualified staffpermanent on site

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Technologies

pro|aqua

reverse osmosis

electro-chemicalpretreatment, no additional chemicals used

average production: 3.3 m³/d(max reached: 4.7 m³/d)

average salinity: 980 µS/cm

start of operation: July 2010

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Technologies

Fraunhofer ISE

Membrane distillation(ambient pressure, watervapor passes a membraneand condensates)

design production: 5 m³/d design salinity: <100 µS/cm

start of operation: July 2010

System in R&D stage

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Technologies

Terrawater

evaporation with bypasstechnology

chemical free operation

average production: 1.4 m³/d (max reached: 2.1 m³/d)

average salinity: 6 µS/cm

start of operation: July 2010

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Technologies

Solar-Institute Jülich/IBEU

multi stage desalination

runs without electrical power, chemical free, self-regulated

average production: 0.5 m³/d (~85 L/d per module max reached: 0.6 m³/d)

average salinity: 5-10 µS/cm

start of operation: December2010

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Type of Investment

investment into desalination plant

depending on the type of plant ranging from 4-10 EUR/m³ (only investment of desalination plant)

further cost factors

– natural site conditions

– existence of infrastructure such as roads, electricity, network, wells

– Use of conventional or renewable energy

operation and maintenance costs

users of desalination technology (individually sized)

lodges, farms, industries (→ private investments)

population in rural areas (→ public investment)

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Questions?

Contact:Marian Brendam.brenda@iwar.tu‐darmstadt.de+49 6151 16 3658