Abu Dhabi has almost no fresh water. Everything that comes out of a tap in the emirate was seawater
until fairly recently — and for most of the last thirty years, making it drinkable meant boiling it with
waste heat from a gas power station.
That arrangement is being dismantled. The story of Abu Dhabi desalination is really the
story of one word the sector uses constantly: decoupling.
The old way, and why it had to go
Thermal desalination is a by-product business. A gas turbine generates electricity; its waste heat
flashes seawater into steam; the steam condenses into fresh water. The plants that do it are named on the
operator’s own pages: Taweelah B runs multi-stage flash distillation; Taweelah A1 is a combined-cycle power
plant with thermal desalination attached; Mirfa 1 absorbed a 102,000 cubic-metre-a-day multi-stage flash
plant.
It works, and it has a fatal design flaw: you cannot make water without also making
electricity. Demand for the two does not move together. Water demand is steady; power demand spikes
in summer. Tying them together means burning gas you do not need to make water you do.
Reverse osmosis breaks the link. It pushes seawater through membranes using electricity alone — so it can
run on solar or nuclear power, and it can run when the grid is quiet.
The efficiency gap is not marginal. Emirates Water and Electricity Company puts it the same way on
multiple project pages: RO plants are “up to 96 per cent more efficient than traditional thermal
desalination plants and enable a more than 85 per cent reduction in carbon emissions associated with water
production.”
Who actually runs this
EWEC is “the sole procurer of water and power within the Emirate of Abu Dhabi and
beyond”. It plans, forecasts, purchases and despatches — it does not own the plants. It was formed in
November 2018, succeeding the Abu Dhabi Water and Electricity Company, and it is part of ADQ.
Two structural points that get muddled constantly:
EWEC and TAQA are sister companies under ADQ. TAQA does not own EWEC. TAQA’s position is
at the individual project level — and it is a striking one. Across the emirate’s generation and desalination
assets, TAQA holds 60% of essentially every one, with international operators taking the
minority: ENGIE, Marubeni, Sumitomo, ACWA Power, GS Inima, Sojitz, Jera, KEPCO.
The regulator is the Department of Energy. EWEC’s Statement of Future Capacity
Requirements is published by EWEC but approved by the Department, which also issues the water desalination
development licences.
What the shift has achieved
| Measure | Figure | Source and date |
|---|---|---|
| Carbon intensity of water production | 16 kg/m³ in 2021 → under 1 kg/m³ by 2031, a 93% reduction | EWEC, February 2024 |
| RO capacity by 2031 | Over 3.5 million m³/day, serving 92% of projected demand | EWEC, February 2024 |
| Share of water through RO by 2030 | 90% | EWEC chief executive, July 2024 |
| Water production emissions by 2030 | 94% reduction; electricity carbon intensity down 54% | EWEC, September 2025 |
Note that the 2030 and 2031 targets come from different documents and are stated differently. We are
attributing each to its own date rather than merging them into a single tidy claim.
EWEC’s chief executive, Othman Al Ali, has described the planning as having “steered us away from a
reliance on gas-fired power and thermal desalination towards a diversified and sustainable energy mix. We
are further decoupling water and electricity production.”
The largest single asset in that shift is Taweelah RO, at 909,000 cubic metres a day. It
is frequently called the world’s largest desalination plant. EWEC’s own claim is narrower and worth keeping
narrow: the largest reverse osmosis plant, and the largest commercially operating RO facility.
The worked example: Shuweihat S1
If you want to see decoupling happen to a specific building, this is it.
In April 2025, EWEC, TAQA, ENGIE and Sumitomo announced that Shuweihat S1 would be
reconfigured from a cogeneration power and water desalination facility to a power plant only,
under a 15-year agreement, providing flexible reserve supply to support the integration of renewable and
clean energy.
A plant built to make water as a by-product of electricity has stopped making water. Its role now is to
be available when the sun is not.
And EWEC’s own plant page has not caught up. As at 20 August 2026 it still describes S1
as a “power generation and water desalination facility” and still headlines a combined S1-and-S2 output of
910,000 cubic metres of water a day — a configuration that has been retired. Anyone quoting that page is
quoting a plant that no longer exists in that form.
Three more places the public record is out of date
Mirfa 2 is operating. ENGIE’s project page states it was “completed in 2026 and now
operational”, at 120 million imperial gallons a day. EWEC’s site still files it under plants
under construction, with a target commercial operation date of Q4 2025 — a date nine months in the past.
The Abu Dhabi Islands project halved. In July 2023 EWEC tendered an “Abu Dhabi Islands
RO” scheme covering two plants — Saadiyat and Hudayriyat — at a combined 100 million gallons a day. By July
2024 the same procurement, carrying identical qualification statistics, had become “Saadiyat Island RO”:
one plant, around 60 million gallons a day. Hudayriyat dropped out. Descriptions of a 100-million-gallon
two-island project are describing a superseded tender, and no award has been announced.
EWEC’s own site cannot agree on how many plants it buys from. Its navigation carries two
blocks, on every page: one saying it procures from 28 plants across the UAE, 17 current and 11 in the near
future; the other saying 16 plants, 12 current and four in the near future. Neither matches the plant
listings on the site, which come to roughly 25 entries — and even that is complicated, because several
“entries” are complexes holding three plants each.
So we are not giving you a number. That EWEC publishes two of them simultaneously is the more useful
fact.
The part that is not solved
Desalination produces brine — hypersaline water returned to the Gulf, warmer and saltier than what came
out. In a shallow, slow-flushing, heavily desalinated sea shared by eight countries, it is the obvious
long-term question.
It is also the part with almost no published data. The only verified primary reference we could find is
EWEC supplying 1,200 litres of brine discharge to five university teams for the third round
of Sandooq Al Watan’s ReThink Brine Challenge, to prototype construction materials or medical applications
from it — with teams from NYU Abu Dhabi, Khalifa University, the American University of Sharjah and Zayed
University.
That is brine framed as an innovation opportunity. We could not trace a single published figure for how
much brine Abu Dhabi discharges, at what salinity, or with what measured effect. We are not inventing one,
and readers should treat any such number they encounter with suspicion until someone names its source.
The reserve nobody can document
The same problem, more starkly, applies to the Liwa Strategic Water Reserve — an aquifer
storage scheme in the Al Dhafra desert, into which desalinated water is injected during normal operations
and recovered in an emergency.
It is a genuinely significant piece of infrastructure and, as far as we can establish, it is not
documented on any primary source we could reach. It is absent from EWEC’s site; TAQA Transmission’s
portfolio pages contain no mention of Liwa, aquifers or strategic water storage.
Meanwhile the secondary figures in circulation contradict each other on capacity, on how many days of
supply it holds, on the number of wells, on the cost, and on what year it was completed. We are describing
it and stopping there.
Why this matters
Water security in the Gulf is usually discussed as a climate story. In Abu Dhabi it is closer to an
engineering and procurement story: a single buyer, a regulator that approves its plans, one company holding
60% of the assets, and a deliberate two-decade migration off a technology that tied every litre to a gas
turbine.
On the evidence, it is working. Our guides to the
UAE energy mix, to
Masdar, to
nuclear power in the GCC and to
GCC clean
energy investment cover the generation side that now powers the membranes, and our profile of
ADQ under L’IMAD
covers the holding company that sits above both the buyer and the builder.
Primary sources: EWEC’s
planning page, carrying its
mandate, its 2018 formation and both conflicting plant counts; its plant pages for
Taweelah RO,
the Al
Taweelah complex,
Shuweihat,
Umm Al Nar
and Mirfa 1; its
releases on
nearly
emissions-free water production by 2031, the
reconfiguration
of Shuweihat 1, the
Saadiyat
Island RO proposals and the
ReThink
Brine Challenge;
ENGIE
on Mirfa 2; and the
Abu Dhabi Department of
Energy. All checked 20 August 2026.
