International
Training
Program
1-4 February 2011
Lordos Beach Hotel
Larnaca, Cyprus
Day 2: Reverse Osmosis Desalination
Systems – Design & Costs
15:30-16:30
Desalination Costs
Nikolay Voutchkov, PE, BCEE
Water Globe Consulting
Desalination Project Costs

Key Components and Factors

Construction Costs

O&M Costs

Total Cost of Water Production

Methods to Minimize Costs
Desalination Cost Components

Capital Costs:



Operation & Maintenance Costs:



Construction (Direct or “Hard”) Capital Costs;
Indirect (“Soft”) Capital Costs.
Variable;
Fixed.
Cost of Water:


Annualized Capital Costs;
O&M Costs.
Seawater Desalination Plant –
Construction Costs
Pretreatment –
15% to 20 %
of Construction costs
RO System –
40 % to 60 % of
Construction Costs
Discharge – 5 to 15 %
of Construction Costs
Intake – 5 to 20 %
of Construction Costs
Indirect (Soft) Costs –
15 to 50 % of Total Capital Costs
Cost Item
% of Total Capital Costs
Project Engineering
5.0 – 12.5 %
Project Development
2.0 – 10.0 %
Project Financing
3.0 – 17.5 %
Contingency
5.0 – 10.0 %
Total
15 – 50 %
Indirect Capital Cost Comparison

Conventional Water Treatment Plant:
Indirect Costs - 15 to 25 % of Capital Costs;

Seawater Desalination Plant:
Indirect Costs - 15 to 50 % of Capital Costs.

Where Does the Difference Comes from? – Cost of Project
Related Risks (Intake and Source Water Quality; Permitting;
Technology; Reliability, etc.).
This Difference Helps Understand Why Majority
of the Large SRWO Projects Worldwide are
Mainly Completed Under BOOT Delivery!
Intake Construction Costs –
Key Factors

Very Dependent on Source Water Quality

Usually Between US$50 and 100/m³/day

Beach Well Intakes Usually Less Costly

Horizontal and Slant Wells Comparable to
Open Intakes

Infiltration Galleries Often are More
Expensive than Open Intakes
Open Intakes
Construction Costs
Well Intakes
Construction Costs
Pretreatment
Construction Costs

Very Dependent on Source Water Quality &
Type of Treatment Technologies

Usually Between US$100 and 300/m³/day

High Quality Well Water Sources Require
Only Cartridge Filtration (Low Cost
Pretreatment)

Single-stage Granular Media Filtration
Usually is Less Costly than Membrane
Pretreatment
Seawater Pretreatment
Construction Costs
SWRO Plant
BWRO
Plants
w/ Sallow &
Deep Wells
SWRO System
Construction Costs

Dependent on Source Water Quality & Target
Product Water Quality

Usually Between US$300 and 1,000/m³/day

Single-stage/Single Pass SWRO System is
Least Costly

Additional Costs for Two-Pass/Two-Stage
RO System May Vary Between 15 and 30 %
of the These of Single Pass/Single Stage
SWRO System
Costs of Key RO System
Components
Component
8-inch SWRO Membrane Element
8-inch SWRO Pressure Vessel
RO Train Piping
Construction Cost (US$/item)
US$450 –US$600/element
US$4,000 - US$6,000/vessel
US$200,000 – US$600,000 /RO Train
RO Train Support Frame
US$150,000-US$400,000/RO Train
RO Train Instrumentation &
Controls
US$20,000 – US$90,000/RO Train
High Pressure Pumps
US$150,000 – US$800,000/RO Train
Post-treatment
Construction Costs

Dependent on Target Water Quality:







Hardness
Alkalinity
pH
Need for Addition of Corrosion Inhibitors
Type of Disinfection
Need for Addition of Fluoride & Magnesium in
the Drinking Water
Usually Between US$20 and 50/m³/day
Post-treatment Construction
Costs
Concentrate Disposal
Construction Costs
Disposal Method
New Outfall w/Diffusers
Construction Cost
(US$ Million/ML/d)
0.50 – 1.50
Power Plant Outfall
0.05 – 0.15
Sanitary Sewer
0.03 – 0.10
WWTP Outfall
0.08 – 0.45
Deep Well Injection
0.65 – 1.65
Evaporation Ponds
0.75 – 2.50
Zero-Liquid Discharge
3.50 – 7.50
Key Capital Cost Components –
40,000 m3/day Plant w/
Low-Cost Intake & Outfall
Cost Item
Cost (US$)
% of Total
Intake
2.76 MM
4.8 %
Pretreatment
4.64 MM
8.0 %
RO System Equipment
18.56 MM
32.0 %
Post Treatment
1.16 MM
2.0 %
Concentrate Disposal
1.45 MM
2.5 %
Buildings
1.74 MM
3.0 %
Waste and Solids Handling
0.87 MM
1.5 %
Electrical & Instrumentation
1.30 MM
2.2 %
Other Items
2.90 MM
5.0 %
Total Construction (Direct) Costs
35.38 MM
61 %
Engineering Services
5.80 MM
10.0%
Development, Financing & Contingency
16.82 MM
29 %
$58.0 MM
100 %
TOTAL
Capital Costs and Plant Size
Annual O&M Cost Breakdown
Cost Item
Range
(% of Total O&M Costs)
Variable O&M Costs
50.5 – 85.0%
Fixed O&M Costs
15.0 – 49.5%
Total
100 %
Variable O&M Costs
Cost Item
(% of Total O&M Costs)
35.0 – 58.0 %
Power
Chemicals
5.5 – 9.0 %
Membranes & Cartridges
6.5 – 11.0 %
Waste Stream Disposal
3.5 – 7.0 %
Total
50.5 – 85 %
Fixed O&M Costs
Cost Item
(% of Total O&M Costs)
Labor
4.0 – 11.0 %
Maintenance
Environmental &
Performance Monitoring
3.0 – 13.0 %
Indirect O&M Costs
Total
7.0 – 20.5 %
15.0 – 49.5 %
1.0 – 5.0 %
Indirect O&M Costs – 7 to 20.5 %
of Total Costs

Administrative Costs;

Operations Insurance;

O&M Reserve Funds Required by Investor (Project
Risks);

Contingency;

Staff Training and Professional Development;

Operator Fees.
O&M Costs & Cost of Water
40,000 m3/day Plant w/ Low-Cost Intake & Outfall
Cost Item
Cost (US$/yr)
% of Total
Energy
3.24 MM/yr
55.5 %
Chemicals
0.35 MM/yr
6.0 %
Replacement of RO Membranes & Cartridge Filters
0.62 MM/yr
10.6 %
Waste Stream Disposal
0.26 MM/yr
4.4 %
4.47 MM/yr
76.5 %
Labor
0.33 MM/yr
5.7%
Maintenance
0.38 MM/yr
6.5 %
Environmental & Performance Monitoring
0.09 MM/yr
1.5 %
Other O&M Costs
0.57 MM/yr
9.8 %
1.37 MM/yr
23.5%
$5.84 MM/yr
100 %
Total Variable Costs
Total Fixed Costs
TOTAL ANNUAL O&M COSTS
Annual O&M Costs = US$5.84 MM/(40,000 m³/dayx365 days) = US$0.40/m³
Cost of Water
40,000 m3/day Plant w/ Low-Cost Intake & Outfall



Annual O&M Costs = US$5.84 MM/yr ($0.40/m³)
Capital Costs, Cap = US$58 MM
Capital Cost Recovery Factor,
CRF = [(1+i)ᵐ - 1] / [ix(1+i)ᵐ]
Where: m – period of repayment of capital
expenditures; i – interest rate of capital
For example, for m = 20 years & i = 5%
CRF = [(1+0.05)²º - 1] / [0.05 (1+0.05)²º] = 12.462

Annualized Capital Costs = Cap/(CRF x Qp x 365 d)
= US$58 MM/(12.462 x 40,000m³/d x 365 d) = $0.32/m³

Cost of Water = $0.40 + $0.32 = $0.72/m³
Cost Comparison of 100 ML/d SWRO
Plant with Conventional and
Membrane Pretreatment
Comparison of O&M costs
and Costs of Water Production –
100 ML/d SWRO Plant
Conventional
Pretreatment
Membrane
Pretreatment
Cost of Water Production
Cost of Water of
Recent Desalination Projects
Costs of Recent US SWRO Projects
Project
Status
Capital Cost
(US$)
Annual O&M
Cost (US$/kgal)
Cost of Water
(US$/kgal)
0.6 MGD
Sand City, CA
In Operation
since 2010
US$11.9 MM
US$1.15/kgal
US$2.91/kgal
25 MGD
Tampa Bay, FL
In Operation
since 2008
US$138 MM
US$1.54/kgal
US$3.48/kgal
50 MGD
Carlsbad, CA
In Financing
US$350 MM
US$1.75/kgal
US$4.00/kgal
2.5 MGD
Santa Cruz, CA
In Planning
US$59-64 MM
US$3.94/kgal
US$7.6-8.0/kgal
2.5 MGD
Brownsville Demo
Project, TX
In Planning
US$22.5 MM
US$2.80/kgal
US$4.38/kgal
25 MGD-80 MGD
Coquina Coast, FL
In Planning
US$180 MM US$560 MM
US$1.99/kgal
US$4.47/kgal
(US$5.35-US$6.10
w/ conveyance)
Key Factors Affecting Costs

Source Water Quality - TDS, Temperature, Solids, Silt and Organics Content.

Product Water Quality – TDS, Boron, Bromides, Disinfection Compatibility.

Concentrate Disposal Method;

Power Supply & Unit Power Costs;

Project Risk Profile;

Project Delivery Method & Financing;

Other Factors:



Intake and Discharge System Type;
Pretreatment & RO System Design;
Plant Capacity Availability Target.
Source Water Quality & Costs
Water Source
(TDS, ppt /Temperature, ºC)
Construction
Costs
O&M Costs
Cost of
Water
1.00
1.00
1.00
Caribbean
(36 ppt /26 ºC)
1.04-1.35
1.02-1.10
1.03-1.22
Mediterranean
(38 ppt /24 ºC)
1.06-1.40
1.04-1.15
1.05-1.28
Gulf of Oman/Indian Ocean
(40 ppt /30 ºC)
1.15-1.50
1.10-1.25
1.12-1.38
Red Sea
(41 ppt /28 ºC)
1.18-1.55
1.12-1.28
1.15-1.42
Arabian Gulf
(45 ppt /26 ºC)
1.25-1.60
1.15-1.33
1.20-1.48
Pacific/Atlantic Ocean
(33.5 ppt /18 ºC)
Product Water Quality & Costs
Target WQ
Constr.
Costs
O&M
Costs
Cost of
Water
TDS/Cl = 500/250 mg/L;
Boron = 1 mg/L.
1.0
1.0
1.0
TDS/Cl = 250/100 mg/L;
Boron = 0.75 mg/L.
1.15-1.25
1.05-1.10
1.10-1.18
TDS/Cl = 100/50 mg/L;
Boron = 0.5 mg/L.
1.27-1.38
1.18-1.25
1.23-1.32
TDS/Cl = 30/10 mg/L;
Boron = 0.3 mg/L.
1.40-1.55
1.32-1.45
1.36-1.50
Key Project Risks and Costs

Permitting Risks – Very High for Large Plants;

Source Water Risks – High for Most Large Plants;

Technology Risks – High, Especially for New Technologies with Limited Track
Record;

Operational Risks – High – Experienced Operator Needed;

Desalinated Water Demand Risks – High When Cost of Desalinated Water
Significantly Higher than That of Existing Supplies;

Power Supply & Entitlement Risks – Moderate;

Regulatory Risks – Moderate;

Construction Risks – High – Limited Experience;

Financial Risks – High.
Project Financing Alternatives

Government Financing:



Key Advantage - Lowest Cost for the Final User;
Key Disadvantages – Scarce & Limited.
Bonds and Construction Loans:


Key Advantage – Low Cost Funds (3 to 8 % rate);
Key Disadvantages – Limited by the Credit Capacity of the Water
Agency & Complex Approval Process.
Private Project Finance:


Key Advantage – Utility Responsible to Pay for Services &
Borrowing Capacity Not Impacted;
Key Disadvantages – Usually More Expensive for Small and LowRisk Projects.
Project Delivery Alternatives

Design-Bid-Build (DBB):



Design-Build-Operate (DBO)/”Alliance”:



Key Benefit - Utility Owns All Assets;
Key Disadvantages – Utility Takes All Risks and Reduces Borrowing
Capacity.
Key Benefit – Utility Owns All Assets;
Key Disadvantages – Utility Shares Some Construction & Operations
Risks and Reduces Borrowing Capacity.
Build-Own-Operate-Transfer (BOOT):


Key Benefit – Utility Transfers Most Risks to Private Sector and Only
Pays for Water it Receives;
Key Disadvantages – Utility Does Not Own the Assets.
Risk Allocation Profiles for BOOT
& Alliance (DBO) Project Delivery
Type of Project Risk
BOOT
Alliance/DBO
Permitting
Private
Public
Source Water
Private
Shared
Technology
Private
Shared
Operations
Private
Shared
Water Demand
Public (Take or
Pay – Private
Equity at Risk)
Public
Power Supply
Private
Public
Construction
Private
Shared
Financial
Private
Public
Worldwide the Lowest Cost of
Desalinated Seawater Has Been
Delivered
Under BOO/BOOT Contracts!
Largest SWRO Desalination
Projects Worldwide
Cost of Water
(US$/m³)
Power Use
(kWh/m³)
& TDS
Ashkelon, Israel – 330 ML/d
(Largest in The World) – BOOT
0.53
3.8
(40 ppt)
Point Lisas, Trinidad – 130 ML/d
(Largest in The Americas) - BOOT
0.72
4.8
(38 ppt)
Tuas, Singapore – 136 ML/d
(Largest in Asia) - BOOT
0.48
4.3
(33 ppt)
Barcelona, Spain – 200 ML/d
(Largest in Europe) BD+O
1.16
4.4
(38 ppt)
Fujariah, UAE – 170 ML/d
(Largest in the Middle East) - BOOT
0.90
4.5
(38.5 ppt)
Sydney, Australia – 250 ML/d
(Largest in Australia) – DBO (Alliance)
2.29
4.2
(36 ppt)
SWRO Plant
Year 2004/09 The Five Lowest Cost
SWRO Project Bids Worldwide
Cost of Water
(US$/m³)
Power Use
(kWh/m³)
& TDS
Sorek, Israel – 411 ML/d
BOO (startup – 2014)
0.53
3.7
(40 ppt)
Mactaa, Algeria – 500 ML/d
BOOT (startup – 2013)
0.56
3.7
(40 ppt)
Hadera, Israel – 330 ML/d
BOO/co-located (startup – 2009)
0.60
3.7
(40 ppt)
Cap Djinet, Algeria – 100 ML/d
BOO (startup – 2010)
0.72
4.0
(38 ppt)
Carlsbad, USA – 189 ML/d
BOO co-located (startup – 2012)
0.74
2.9
(33.5 ppt)
SWRO Plant
What All Recent BOOT Projects
Have in Common?

All Yielded the Lowest Costs and Power Use
of Desalinated Water in Their Respective Markets;

Plant Performance & Permitting Risks Reside with the Private Sector;

Debt Repayment is Private Sector Obligation;

Private Sector Only Gets Paid for Delivering Product Desalinated
Water;

Public Utility Can Buy Out (Transfer) Project Ownership Once Plant
Has Proven Its Long-term Performance.
Ashkelon – Lowest Cost of Water
Worldwide – How Did They Do It?
Ashkelon – How Did They Do It?

Low Cost Conventional Pretreatment – Single Stage Dual Media Filters;

Large Size (20-micron) Cartridge Filters;

Three-Center RO Design w/ Pressure Exchangers:

Low Cost Post-Treatment – Calcite Filters & Blending;

Self-Power Generation – 80 MW Gas Generators and Purchase of Rights
to Gas Field Use;

Discharge Collocation with Power Plant in Well Mixed Tidally Influenced
Zone – No Need for Outfall.
Sydney and Huntington Beach
Desal Plant Construction Costs
Costs
Sydney
250 ML/d
US$
Desalination Plant
492
Intake and Outfall
230
Delivery
557
Project Costs
260
Total Capital Costs
Note: Sydney Costs Source – WDR - July 2007
1,539
Huntington
Beach
189 ML/d/(250
ML/d)
US$
310
(410)
16
(21)
110
(146)
61
(81)
497
(658)
Perth & Sydney SWRO Plants
Cost Breakdowns
Perth
Sydney
125
<1
26.2
$325
250
4.5
14.3
$1,539
$281
$44
$982
$557
$25
$120
Capacity (ML/d)
Distance from intake (km)
Distance to delivery (miles)
Total Capital Cost ($M)
Total Capital Cost – Desal Plant ($M)
Total Capital Cost - Delivery ($M)
Annualized Capital Cost ($M/yr)
Total Annual O&M Costs ($M/yr)
Annual O&M Cost – Desal Plant ($M/yr)
Annual O&M Cost – Delivery ($M/yr)
Cost of Water – Capital Component ($/m3)
Cost of Water – O&M Component ($/m3)
$17
$16
$46
$42
$1
$0.70
$0.44
$4
$1.65
$0.58
Cost of Water – Delivery Component ($/m3)
$0.02
$0.06
Total Water Cost, $/m3
$1.16
$2.29
adapted from Waterlines:NWC Australia
Be Careful When Comparing Costs!

Projects Differ By:








Source Water Salinity and Temperature;
Product Water Quality;
Unit Cost of Construction, Labor and Permitting;
Cost of Capital;
Unit Cost of Power;
Source of Equipment Supply;
Project Completion Schedule.
Projects Have to Be Normalized for These and Other Factors for
Accurate Comparison.
Typical Cost and Energy Ranges
(Medium & Large SWRO Plants)
Classification
Cost of
Water
Production
(US$/kgal)
SWRO System
Energy Use
(US$/kgal)
Low-End Bracket
2.0 - 3.0
9.5 – 10.5
Medium Range
3.5 – 5.0
11.0 - 12.0
High-End Bracket
6.5 - 11.5
12.5 – 14.0
4.0
11.5
Average
Common Features of Low-Cost
Desalination Projects

Low Cost HDPE Open Intakes or Beach Wells;

Near-Shore/On-Shore Discharges w/o Diffuser
Systems or Co-discharge w/ Power Plant of
WWTP Outfalls;

Point of Product Water Delivery within 5 Miles
of Desalination Plant Site;

RO System Design w/ Feed of Multiple Trains
by Common High Pressure Pumps and Energy
Recovery Systems;

Turnkey (BOOT, BOO) Method of Project
Delivery.
Key Reasons for Cost Disparity Between
High-End & Low-end Cost Projects
(US$2.0 – 3.0 vs. US$6.5-11.5/kgal)

Desalination Site Location (NIMBI vs. Science Driven)

Costly Plants Have Overly Long Product Water Delivery Pipelines
• 120 MGD Melbourne Plant – Cost of Plant/Delivery + Power Supply Systems =
US$1.7 BB/1.1 BB (50 miles)
• 66 MGD Sydney SWRO Plant – Cost of Plant/Delivery System
= US$560 MM/US$490 MM (10 miles of underground tunnel under Botany Bay).

Environmental Considerations


Phasing Strategy



Complex Intakes & Diffuser Systems
Intake and Discharge System Capacity;
Pretreatment & RO System Design;
Labor Market Pressures
 Method of Project Delivery & Risk Allocation
Where Future Cost Savings Will
Come From?
Main Areas Expected to Yield Cost Savings in
the Next 5 Years (20 % Cost Reduction Target)







Improvements in Membrane Element Productivity:
- Polymetric Membranes (Incorporation of Nano-particles Into
Membrane Polymer Matrix) – CSIRO & UCLA;
- Larger Membrane RO Elements (16” Diameter or Higher).
Increased Membrane Useful Life and Reduced Fouling:
- Smoother Membrane Surface – Carbon Nanotube Membranes –
CSRO & University of Texas (Austin).
- Increased Membrane Material Longevity;
- Use of Systems for Continuous RO Membrane Cleaning;
- UF/MF Membrane Pretreatment.
Commercial Forward Osmosis Systems;
Co-Location With Power Plants;
Regional Desalination and Concentrate Disposal;
Larger RO Trains and Equipment;
Full Automation of All Treatment Processes.
Nano-Structured SWRO
Membranes
Potential to
Reduce 60 to 80 %
of Energy Costs &
15 to 25 % of Cost
of Water
OASYS
Research Directions to Meet the
Long-Term 80 % Cost Reduction Goal

Improve Membrane Useful Life and Productivity;

Develop Corrosion Resistant Non-Metallic Materials to
Replace High-Quality/High Cost Stainless Steel RO
Piping;

Reduce Pretreatment Costs;

Develop New-Generation Energy Recovery Systems;

Introduce Low-Cost Technologies for Beneficial
Concentrate Use and Disposal;

Explore New Technologies for Seawater Desalination
Different from RO and Thermal Evaporation.
Aquaporine-Based
Desalination
“The Best” of Seawater Desalination
Present Status & Future Forecasts
Parameter
Today
Within 5 Years
Within 20 Years
US$0.6-0.8
US$0.5-0.6
US$0.1-0.2
Construction Cost
(Million US$/ML)
1.2-2.4
1.0-2.0
0.5-1.0
Power Use
(kWh/m³)
2.8-4.0
2.5-3.5
2.0-2.5
5,000-12,000
8,000-15,000
20,000-40,000
Membrane Useful Life
(years)
5-7
7-10
10-15
Plant Recovery Ratio
(%)
45-50
50-55
55-65
Cost of Water (US$/m³)
Membrane Productivity
(gallons/day/membrane)
Concluding Remarks

The Ocean Will Become One of the Key Sources of
Reliable and Draught-Proof Coastal Water Supply in the
Next 10 to 20 Years;

Large-scale Seawater Desalination is Economical
Today and Will Become Even More Cost-Competitive in
the Future;

The Future of Seawater Desalination Is Bright – 20%
Cost of Water Reduction in the Next 5 Years;

Long-term Investment In Research and Development
Has the Potential to Reduce the Cost of Desalinated
Water by 80 % In the Next 20 Years.
Seawater Desalination Costs
Questions?