© Fraunhofer ISE

SOLAR SEAWATER DESALINATION

Dr.–Ing. Joachim Koschikowski

Fraunhofer-Institute for Solare

Energy Systems ISE

© Fraunhofer ISE

Outline

Development of the global

desalination market

Overview on desalination

technologies

Decentralized versus centralized

water supply systems

Fraunhofer ISE activities on solar

desalination

© Fraunhofer ISE

The shortage of clean and safe water is one of the

most critical problems to be solved

Water has no alternative !!!

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Water

EnergyFood /

Industry

The shortage of clean and safe water is one of the

most critical problems to be solved

Water has no alternative !!!

© Fraunhofer ISE

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Mio

m³/

day

Global desalination capacity

Global Capacity :

88 Mio m³/day

Development of the global desalination market

Desalination for industrial and domestic fresh water

supply is of increasing importance!

Multi Effect Dist. 7%

Multi Stage Flash 21%

Reverse Osmosis 66%13.000 small and

medium scale

systems with an

average capacity of

1500m³ (25% of total

production)

Membrane based

technology has

increasing share

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Development of the global desalination market

Mega plants

> 1Mio m³/Tag

Small scale,

distributed systems

< 1000 m³/Tag

Two major trends can be observed

Desalination for industrial and domestic fresh water

supply is of increasing importance!

Global Capacity :

88 Mio m³/day

13.000 small and

medium scale

systems with an

average capacity of

1500m³ (25% of total

production)

Membrane based

technology has

increasing share

© Fraunhofer ISE

The utilization of renewable energy for desalination is

of increasing interest!

Water shortage and high

solar yield are

geographically correlated

Example:

The production of 1m³ of

fresh water by solar

desalination requires 5 to

10 m² of PV

Development of the global desalination market

© Fraunhofer ISE

Steam at 70°C

0.08 - 0.1 t/tproduct

Thermal energy input ~50 – 60kWh/m³ Cooling

1.5-2.5kWh/m³product

Sea water at 20 – 35°C

Electrical energy input

Cooling blow down

Energy demand

Investment costs

Number of effects 2 -20

Basic set up of a Multi Effect Desalination (MED)

system

Overview on desalination technologies

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Heat

storage

Fossil

back up

Principle design of a CSP – MED plant

Overview on desalination technologies

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Electricty

3.5-6 kWh/tproduct

Basic set up of a Reverse Osmosis (RO) system

60 – 80bar

Pressure recovery

Overview on desalination technologies

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Basic set up of a Reverse Osmosis (RO) system

PV-RO - stand alone system configuration for small scale application

Overview on desalination technologies

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Basic set up of a Reverse Osmosis (RO) system

PV-RO – grid connected system configuration for large applications

Overview on desalination technologies

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Driving force:Difference of water vapor pressure between both membrane boundary layers

Evaporator Condenser

Hydrophobic

Membrane

Overview on desalination technologies

Basic set up of Membrane Distillation system

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Driving force:Difference of water vapor pressure between both membrane boundary layers

Basic set up of Membrane Distillation system

Overview on desalination technologies

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RO: Reverse Osmosis

ED: Electro Dialysis

MSF: Multi stage flash

MED: Multi Effect Distillation

VC: Vapor Compression

STIL: Simple Solar Stil

MEH: Multi Effect Distillation

MD: Membrane Distillation

Renewable energy sources for desalination

Overview on desalination technologies

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Low water production costs

Large urban communities can be

supplied with water

Financing is possible since successful

business models exist

Complex, expensive, lossy distribution

grids are required

Minimized distribution costs

Water supply to remote regions

Minimized distribution grid but

maintenance of system is difficult

Financing of systems difficult since

attractive business models do not

exist

Centralized water supply Decentralized water supply

Decentralized distributed water supply systems

versus centralized systems

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Stand alone solar only supply is

challenging since large scale energy

storage is expensive

Solar energy can be used efficiently

as fuel saver

100% coverage by solar energy

possible in average annual net

balance in grid connected systems

Full coverage by solar energy in

stand alone systems possible –

further development for cost

reduction

Very remote regions can be reached

CAPEX is high but levalized costs of

water can be the cheapest option

Centralized water supply Decentralized water supply

Solar energy as prime mover for desalination

systems

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Application :

Solar thermal power plants with large scale desalination plant for energy and

water supply to coastal cities

Fresh water production for irrigation in agriculture

Challenges:

Locations which provide favorable conditions for CSP and desalination are

limited (CSP+MED requires co-located installation, dislocated installation for

CSP – RO is more flexible)

Intermittent operation is technically difficult and economically inefficient,

storage or fossil backup is necessary

Piloting and demonstration is costly due to required size of plant

Fraunhofer ISE activities on solar desalination

Conceptual design of CSP + Desalination plants

© Fraunhofer ISE

Approach:

Development of simulation models

Conceptual design of components and systems

Techno-economical evaluation of system designs and boundary conditions

Fraunhofer ISE activities on solar desalination

Conceptual design of CSP + Desalination plants

© Fraunhofer ISE

Application:

Decentralized distributed villages and settlements

Islands with shortage of fresh water

Disaster relief

Challenge:

Adaptation of RO system design to intermittent energy supply

Technical robustness with respect to changing raw water composition

Long term operation with minimized maintenance needs

Minimization of water production costs (Capex – Opex)

Consideration of socioeconomic boundary condition

Development and piloting of solar driven stand alone

desalination systems

Fraunhofer ISE activities on solar desalination

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Solar PV driven RO plant

designed by Fraunhofer ISE

and tested in Cyprus

desalination

filtration

Fraunhofer ISE activities on solar desalination

© Fraunhofer ISE

Gran Canaria Spain

Solar collector : 180m²

Nominal capacity: 5 m³/day

Pantelleria Italy

Waste heat from power plant

Nominal capacity: 5m³/day

Amarika Namibia

Solar collector: 225m²

Nominal capacity: 5 m³/T

Solar thermally driven MD systems developed and tested

by Fraunhofer ISE in different locations

Fraunhofer ISE activities on solar desalination

© Fraunhofer ISE

Basic research on membrane

performance and reliability

Development of new membrane

based desalination modules

Development, installation and

evaluation of lab to pilot scale

desalination systems

Design study and evaluation of CSP

connected desalination systems

Conduction of techno-economical

studies for the evaluation of

renewable driven desalination

systems

Summary of our capabilities in desalination

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Solar PV driven stand

alone ultra filtration (UF)

system for purification of

contaminated surface

water

Capacity: 0,8 – 50 m³/day

Modular and scalable

Long term stand alone operation

with minimum maintenance needs

Summary of our capabilities in water treatment

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Dezentrale Entsalzung und Trinkwasseraufbereitung