Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
In cooperation with
Industry partners
Small-scale Solar-driven Desalination in Namibia
4 Pilot Plants in the villages Amarika and Akutsima
2
Implementation Sites
•Groundwater desalination•Subsurface water storage
•Sanitation & reuse •Rainwater harvesting
3
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
4
Saline Groundwater
Processing and cartography: Mendelsohn 2011
Data source: Bittner Water Consult, Windhoek
5
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
6
Benefitsbefore after
7
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
8
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
9
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
10
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
11
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
12
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
13
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
14
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
15
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)