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Figure 2: specifi c energy
consumption evolution

the environment but also brought lower tariffs. The
specifi c energy consumption of 3.5 kWh/m is Maintenance and parts Consumables
3
now a high level, procurers are now witnessing bid 7% 3% Electrical Energy
submissions coming in with energy consumption 44%
less than 3 kWh/m . Membrane
3
replacement
However, what is often not considered but it is 5%
more remarkable is that this reduction in energy Labor
consumption occurred not because of sophisti- 4%
cation of the design and a CAPEX/Energy tradeoff
but came about by a contemporary reduction of
CAPEX and system simplifi cation.
Fixed Cost
37%
Energy optimization
and PV installation

The Figure 4 shows the technology contribution Figure 3: Water tariff cost breakdown
to SWRO Energy optimization that ahs occurred
in these years. It is remarkable how the adoption
of larger and more effi cient high pressure pumping
system confi gured in a pressure center was capa-
ble of bringing about a signifi cant saving in power
consumption.

On the other hand with PV system electric energy
can be produced as low as 0.02 US$/kWh. The
consequence of this was that developers cove-
red their desalination plants with PV panels to self-
generate energy for the desalination process at a
lower cost than 0.05 US$/kWh imported from the
grid as indicated in a typical examples in Figure 5
(courtesy of Metito).

This enhanced power tariffs and contributed to a
further decrease in specifi c energy consumption of
down to 0.2 kWh/m .
3
With the Hassyan project DEWA came along with
a new and somewhat innovative concept that may Figure 4: technology contribution to SWRO Energy optimization
prelude a further major step in price reduction. Du-
bai’s electric grid is increasingly powered by rene-
wable PV, which outstrips power demand during ting an electric load for the renewable energy intro-
daytime. As a result, DEWA set the electricity price duced in the grid.
at only 0.0245 US$/kWh for the Hassyan IWP. In In future, if we start thinking about desalination
effect, SWRO desalination becomes an important plants in an opportunistic way, the plants can be
element in the decoupling strategy aiming at crea- powered using excess electricity when it is availa-

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