Progress in the Development

of Osmotic PowerPresented at the 2011 Quingdao International Conference

on Desalination and Water Reuse byWerner Kofod Nielsen, Senior Advisor, Statkraft

STATKRAFT IS EUROPE'S LEADER IN RENEWABLE ENERGY. THE GROUP

DEVELOPS AND GENERATES HYDROPOWER, WIND POWER, GAS

POWER AND DISTRICT HEATING, AND IS A MAJOR PLAYER ON THE EUROPEAN ENERGY EXCHANGES.

Gas power

86%

FLEXIBLE POWER GENERATION

RENEWABLE ENERGY

IN RENEWABLES IN EUROPENO. 1

98%

STATKRAFT IN BRIEF

Page 3

100 % OWNED BY THE KINGDOM OF NORWAY

NO. 3 NORDIC POWER GENERATOR

Installed capacity (15.8 GW)

*Nordic excl. Norway, Europe excl. Nordic, World excl. Europe

NONo. 1 powergenerator

(35 %)

SENo. 4 power generator

(5%)

UKExtensive wind power initiatives

GER

Growth outside Europe through SN

Power

Major player within flexible power and trading

Hydropower

Wind power Distribution grid

District heating

Hydro84 %

Wind2 %

Gas14 %

SE EUROPEHydropower development

STATKRAFT’S BASIC BUSINESS CONCEPT

Environment – friendly power production

Page 4 THIS IS A DUMMY TITLE

PRESSURE RETARDED OSMOSIS (PRO) OR OSMOTIC POWER

5 Companypresentation 2009

FROM SALT TO ELECTRICITY

Forecast 2020

COMPETITIVENESS

Hydro, running

Biomass

65

115

Wind, offshore

55

90

65

110

160

Solar, CSPNuclear

85

Gas, CCGT Oil, CC

65

Wind, onshore

80

Coal, PCC Hydro, dam

LCOE €/MWh1

1. Levelized cost of Energy2. Source: EU Second Strategic Energy Review (2008), Moderate fuel price scenario; BCG

Osmotic Power50-100 €/MWh

Potential of 16 - 1700 TWh, of which 180 in Europe

THE TOFTE PROTOTYPE PLANT

Page 8 THIS IS A DUMMY TITLE

PROTOTYPE – MAIN ACTIVITIESIn operation since November 2009 Main activities

Monitoring of membrane performance

Cleaning and maintenance of membranes

PX operation in PRO, pressure requirements

Pretreatment fresh water optimization

Pretreatment seawater optimization

Design and start-up of single membrane module test units

PRE-TREATMENT

Sea water filtration with 50 micron filter

Fresh water filtration with CA UF membrane

Back flushing

Sanitation

After one year low degree of fouling

Page 10 THIS IS A DUMMY TITLE

AFTER ONE YEAR

1. generation membranes and elementsCA membranes, PRO spiral wound designInstalled November 2009

2. generation membranes and elementsTFC membranes, PRO spiral wound designInstalled January 2011

28 m2 per element, 66 elements

Page 11 THIS IS A DUMMY TITLE

RESULTS

Experience with operation of a complete PRO plant

Experience with spiral wound elements

Measurement of power efficiency

Fine tuning of operating parameters

Results with 1. generation CA membranes

Results with 2. generation TFC membranes

Page 12 THIS IS A DUMMY TITLE

PRO MEMBRANE STRUCTURE FOR FLAT SHEET

Barrier Layer (selective layer) : Crosslinked Polyamide Based on m-Phenylene Diamine (MPD)

and tri-Mesoyl Acid Chloride via Interfacial Polymerization Micro-porous Support Layer :

PS or PEI (Thickness ~ 40 - 60 μm) may have finger structure orfoam structure

Support Web :Non-woven Polyester, thickness < 100 μm

Support Web Basedon Non-woven Polyester( Mechanical Strength )

Micro-porous Support Based on PS or PEI

( Mechanical Strength )

Ultrathin Barrier Layer < 0.1 μm( Water Flux and Selectivity )

Cross-section Illustration of TFC PRO Membrane

So far this membrane has given the best results in lab tests and in the Tofte prototype plant

Further development indicates that power efficiency measured in lab tests may exceed 4 W/m2

PRO MEMBRANE STRUCTURE HOLLOW FIBRE

Hollow fibre membranes

May in principle be based on skin inside or outside the fibre

The fibre is self supporting and does not require support web

By proper adjustment of the spinning parameters and the bore liquid composition it is possible to manufacture fibre supports with dense structures both inside and outside the fibre

tfc coating outside the fibre will be a challenge in manufacturing

Fibres with S values < 1 mm has been developed

Page 14 THIS IS A DUMMY TITLE

15

THE STRUCTURE PARAMETER S

The membrane support (and backing) gives an extra resistance to mass transport and should be minimized

memxS τφ∆

=

S can be minimised by: Reducing the thickness of the membrane

support and reinforcement Increase the porosity, Φ Decrease the tortuosity, τ

Structure parameter Membrane thickness

PorosityTortuosity

S is just a physical way to describe the structure of the support for the surface film. It can not be measured directly, but is derived from the PRO measurements. While conventional RO membranes may have S factors of 4 – 8 mm, PRO membranes should have S factors < 0.5 – 1 mm

CURRENT MODULE CONFIGURATION BASED ON FLAT SHEET

16 Statkraft presentation

Modified spiral woundBased on an old patentForeman et. Al 1977

FW FW

BW SW

FW FW

BW SW

First generation elementCA membrane on Hirose backing

This design is not adequate,- due to areas with low flow velocity and poor flow distribution in the envelope

MODULE CONFIGURATION BASED ON HOLLOW FIBRES

Hollow fibre configuration

BWBW

SW

FW

BW

BW

FW

FW FW

SW

FW

BW

BW

FW

FW FW

The hollow fibres are self supporting, which eliminates the need for seawater and fresh water spacers

Advantages: compact design, reduced fouling, improved flow pattern for seawater and fresh water

Challenges: potting, separation of fibres, packing density, manufacturing costs??

One single element may contain > 1,000 m2 membrane area

Page 18 THIS IS A DUMMY TITLE

TESTING OF MEMBRANES AND MEMBRANE ELEMENTS

balance

salt water

balance

water

high pressure pump low pressure pump

back pressure valve

V1 V2

V3

V4

p

t,p,c,mi, T

f low cell

water bath

crossf low cell

membrane

p

Membrane sample testing Membrane element testing

OPTIMAL MEMBRANE POWER PRODUCTION

Wmax for ∆P = ½ ∆π

W = ∆P . Jwater

Flow through membrane [l/m2hr]

Power production [W/m2]

W/m2 = Flow (l/m2/h)*Pressure (bar)*0.0278Ex.: 9.0 (l/m2/h)*11 (bar)*0.0278 = 2.75 W/m2

INTERNATIONAL FOCUS

Osmosis Membrane SummitAmsterdam 2008San Diego 2010TBA 2012

Page 20

Feasibility Prototype 2MW Pilot 25MW Demo

2011-13: 2017: 2020:

STATKRAFT STRATEGIC PATH

2009:

•Tofte prototype

•2000 m2 PRO membrane

•2 MW pilot plant

•200.000 –400.000 m2

PRO membrane

•25MW demo-plant

•5.000.000 m2

PRO membrane

•25MW first commercial plant

•5.000.000 m2 PRO membrane

Vision towards 2030

21

Statkraft operatedOther utility operated

LATEST NEWS

On June 20th Statkraft and Nitto Denko/Hydranauticssigned an agreement with the objectives of:

Development and supply of membranes for osmotic power

Nitto Denko/Hydranautics will develop membranes specifically designed for the use in large scale osmotic power plants

The agreement will accelerate the development of the new renewable energy

The development of more efficient membranes will contribute to making the technology competitive with other new, renewable energy sources and will bring osmotic power further towards future commercialization

Page 22 THIS IS A DUMMY TITLE

CONCLUDING REMARKS

Osmotic Power is a promising renewable ocean energy source

The estimated energy costs for Osmotic Power is comparable with other renewable energy sources

Existing RO membranes, modules and pre-treatment are not suitable for Osmotic Power

Key focus areas are PRO membranes, PRO membrane modules and pre-treatment of fresh and sea water

Prototype and pilot demonstration plants are accelerating the development

Page 23

Page 24 THIS IS A DUMMY TITLE