desalination: new frontier for renewable energy?
TRANSCRIPT
20 March/April 2012 | Renewable Energy Focus
focus:PerspectiveInsights on renewables
Demand for water is increasing
rapidly. Some forecasts foresee €400-
€500bn of investment per annum
- just to keep up with this growing
demand.
Seawater desalination will form an
increasingly important part of coastal
water systems (where much of the
population growth takes place) as an
abundant source of water. And this
is already happening: In recent years
the use of desalination technologies
in extracting potable water from sea-
water has spread beyond the affl uent
and desert-surrounded locations in
the Middle East - and a few loca-
tions in California and Australia - to
major population centres in Southern
Europe, India, East Asia and Africa.
In Southern Europe for example,
Barcelona, Malta and Cyprus already
source the majority of their potable
water from desalination treatment
plants, while recent investments in
Israel have seen more than half the
country’s water supply come from
desalination sources.
Meanwhile, a desalination plant
launched in 2010 in Chennai, India
provides potable water for 2.5 million
people.
What is the link to renewable energy?
The key challenge to deploy-
ing desalination is in the cost of
energy required. The current lead-
ing desalination processes require
large amounts of energy to either boil
seawater (MFS technology), or push
it through sophisticated membranes
(RO technology). It is estimated that
28%- 50% of the total cost of running
a seawater desalination facility is due
to electric power useage, according to
the WaterReuse Association (see http://
www.watereuse.org/sites/default/fi les/u8/
Power_consumption_white_paper.pdf).
Traditionally desalination plants
have been powered by fossil fuels,
either directly drawing energy from
the grid, or co-locating the plants
close to coal- or natural gas-powered
plants. It stands to reason that the
global scale up of desalination tech-
nology driven by the use of fossils
as the primary fuel source is both
extremely expensive — leading to
unaff ordable increases in water cost
to societies — and highly polluting.
For instance in the United Arab
Emirates (UAE), up to 3.5% of the
total electricity produced goes towards
desalination. And continued increases
in power generation capacity are
needed to keep up with the growing
water demands of its growing popula-
tion – not to mention industrialisation.
While thus far increased desalination
electricity requirements have been met
with natural gas power, the invest-
ment and running costs are increasing
rapidly. In Abu Dhabi alone the annual
cost of building, maintaining and
operating desalination plants is due to
reach US$3.22bn by 2016 (see http://
www.emirates247.com/business/economy-
fi nance/uae-desalination-plant-spending-to
-jump-300-2010-10-12-1.302849).
So could the powering up of desali-
nation plants with renewable energy
sources be a logical next step in the
development of seawater desalination?
Desalination: new frontier for renewable energy?
WATER SYSTEMS around the world
are under increasing pressure due to
demands from continued industri-
alisation and urbanisation; growing
populations; and increasing pressure
on agricultural systems. This is driving the early stages of
a revolution in the technologies and business models used
in the water industry. Desalination is already part of this
mix, but could the technologies’ high demand for energy
open up a new market for renewable energy technologies?
In recent years the use of desalination technologies in extracting potable water from seawater has spread beyond the affl uent and desert-surrounded locations in the Middle East - and a few locations in California and Australia - to major population centres in Southern Europe, India, East Asia and Africa (image shows plant in the Caribbean).
Insights on renewables
REF132p20_23.indd 20 12/04/2012 14:29:06
Perspective
21March/April 2012 | Renewable Energy Focus
Until a few years ago the high cost
of renewable energy and the energy
ineffi ciency of the available desalina-
tion technologies made such integra-
tion unfeasible on a large commercial
scale, even though it may have been
possible on a smaller scale (island
developments for example).
Yet in recent years, solar and
wind power costs have come close to
grid-parity precisely in some loca-
tions where seawater is plentiful, and
frequently where there is a freshwater
shortage. At the same time, continued
innovation in desalination technolo-
gies is contributing to the improved
effi ciency of desalination processes.
Research over the past two years
– undertaken by CambridgeIP - has
shown steady progress in making the
desalination technologies more energy
effi cient, as well as increasing the
maturity of direct integration technol-
ogies (see box – About CambridgeIP).
Evidence of innovation and implementation
The integration of desalination
processes with energy sources can be
divided between those:
• Using mechanical power - for
instance solar heat or industrial
processes waste heat; or pressure
from wind or wave power (so called
direct integration), and;
• Using electricity generated from renewable sources to power the
desalination plant (or ‘indirect
integration’).
In both these areas we have seen a
steady acceleration of inventive activ-
ity and deployment of technologies, as
follows:
Industrial processes integrationA number of companies have
developed desalination technologies
intended for direct integration with
solar or waste heat using low-tem-
perature thermal processes - such as
multi-eff ect humidifi cation (MEH) or
solar multistage condensation evapora-
tion cycle (SMCEC).
For instance US-based Altela Inc. has a modular off -grid product operat-
ing on solar thermal energy or waste
heat. Examples of its application to
date include the treatment of waste
water from shale gas extraction.
Other companies such as Ger-
many’s TerraWater and France’s
TMW are developing similar systems
for integration with solar thermal and
waste heat energy.
Solar PV integration Meanwhile, Swiss-based Swis-
sInso has developed a solar-powered
Reverse Osmosis (RO) water purifi ca-
tion system capable of producing up
to 100m3 p/day of pure drinking water
from brackish water or seawater (see
http://www.swissinso.com/en).
The system has been deployed in
rural or remote off -grid locations in
West Africa and the Middle East, and
can integrate off -the-shelf solar PV
and Reverse Osmosis technologies. The
container-based product is modular
and mobile, and contains all the neces-
sary components on delivery that can
be assembled locally. It also contains
a back-up diesel generator in case of
solar PV failure or insuffi cient power.
And a research collaboration
between MIT and King Fahd Univer-sity in Saudi Arabia has developed a
modular Solar PV - RO unit, which
can be used in emergency relief opera-
tions or at the household level.
Wind power integrationBoth Aerodyn and Enercon have
in the past developed integrated wind
energy and desalination units. The
unit developed by Aerodyn works on
About: Ilian Iliev works for CambridgeIP. He is a serial entrepreneur and economist. Ilian has a wide experience in IP and technol-ogy strategy, innovation policy and innovation fi nance.
About: Helena van der Vegt is a Senior Associate with CambridgeIP and leads on projects in the energy and cleantech fi elds. She has worked with multinationals, SMEs, start-ups and public sector organisations, providing advice on R&D and IP strategy throughout technology and innovation lifecycles.
About CambridgeIP
The company has worked with
organisations like the Interna-tional Renewable Energy Agency
and the World Intellectual Prop-erty Offi ce to build a patent and
technology database of more than
4,500 desalination-related inven-
tions (see Van der Merwe, Iliev et
al. (2011), Desalination Technologies
and the Use of Alternative Energies
for Desalination) - as well as 900
inventions relating to the integra-
tion of desalination and renewable
- (see chart in this article). Such
technology information librar-
ies can be used by inventors and
acquirers of technology alike to
identify cutting edge technologies,
identify collaboration partners
and also understand the scope for
innovation in a sector. And it can
also provide an early indicator
of accelerating activity. The full
report can be found here – http://
www.cambridgeip.com/water (note –
readers can click on this link from the
digital issue of the magazine).
Figure 1: Desalination technologies
REF132p20_23.indd 21 12/04/2012 14:29:14
Perspective
22 March/April 2012 | Renewable Energy Focus
mechanical vapour compression (MVC)
technology, using the kinematical
energy of the wind turbine directly to
drive the compressor of the evaporation
desalination plant. And Germany-based
engineering company Synlift Systems has implemented pilot wind-powered
desalination units in the Gulf region,
which integrate off -the-shelf wind tur-
bines and RO desalination technology.
Wave power integrationThe Australian wave energy com-
pany Carnegie Wave Energy Ltd has
combined its wave energy technology
with RO desalination by using the
pressure generated from wave energy
to drive the RO process. Carnegie’s
CETO 3 wave energy product has been
shown to deliver sustained pressures
capable of driving seawater reverse
osmosis for commercial scale plants.
Future technologiesIn addition to the technologies men-
tioned above, there are also a number
of other desalination technologies
under late stages of development
which, once implemented, could be
natural partners for renewable energy
sources, and could even transform
the economics of desalination. For
instance, the crossover of membranes
with nanotechnology is resulting in
membranes that are more effi cient
and more durable, leading to further
effi ciency gains in RO desalination.
Looking even further afi eld, com-
panies such as Canada-based Salt-works is looking to altogether more
novel desalination processes that
could result in up to 80% less energy
requirement. Saltworks’ patented
technology is based on the concentra-
tion diff erence between salt water
solutions through a thermo-ionic
process. Building from electrodialysis,
Saltworks’ stack uses ion exchange
membranes to separate solutions and
transfer salt (see http://www.saltwork-
stech.com/press_20110614.php). Low
temperature waste heat from solar
can help drive the system, but the
system harnesses energy captured in
concentrated salt solutions to initiate
salt transfer.
Saltworks has already delivered
a remote operated desalination unit
to the Canadian Department of National Defence. And the technology
will soon be tested by NASA Ames Research Centre, with hopes that it
could be used on board the Interna-
tional Space Station (ISS) (see http://
saltworkstech.com/media.php).
ConclusionThe integration of renewable
energy with desalination could trans-
form the economics of water supply in
coastal areas. This is already happen-
ing for remote/off -grid and “water-
poor” island locations.
And while potable water is the
primary usage of desalination, low-
cost, sustainably-powered desalina-
tion raises the prospect of supporting
agricultural development in previously
unarable regions (such as through
micro-irrigation), as well as improving
the sustainability of water-intensive
manufacturing operations such as in
food and beverages. This also provides
renewable energy technology and proj-
ect companies with a growing market
niche, where the economics may be
better than that of the mainstream
electricity market, and which could
allow market entry into the value chain
of major industry players.
Online: renewableenergyfocus.com
Using CPV to deliver fresh waterhttp://tinyurl.com/cytj9w4
Utility-scale solar PV project under way in Australiahttp://tinyurl.com/bmfrvgg
Figure 2: Number of patent families over time for desaliantion technologies and their integration with renewable energy
The key challenge to deploying desalination is in the cost of energy required. The current leading desalination processes require large amounts of energy to either boil seawater (MFS technology), or push it through
sophisticated membranes (RO technology).
REF132p20_23.indd 22 12/04/2012 14:29:15