A 128 megawatt nearshore wind farm in the Mekong Delta stood up its first 8 megawatt machine in under 7 days, and the record it set is about turbine size rather than farm size

A tidal flat on the Vietnamese coast where the Mekong finally gives up its silt, brown water over soft mud.

Twice a day the water leaves and the ground appears. Twice a day it comes back.

Standing in it now is a turbine rated above 8 megawatts, the first of sixteen.

It also depends on components being staged ashore in the right order, because a tidal window is no use if the part it was booked for is at the back of the yard.

It went from nothing to standing in less than a week. The second one took under five days.

The schedule is not set by weather.

It is set by the tide.

Why shallow water is harder to build in than deep water

Offshore installation normally means a jack up vessel with legs long enough to reach the seabed and lift itself clear of the swell.

A tidal flat defeats that immediately. There is not enough water to float a vessel of that draft at low tide, and not enough firm ground to drive on at any tide.

The mud itself is the second problem. Recent deltaic silt has very low bearing capacity, so anything heavy that sits on it settles, and a crane that settles unevenly stops being a crane.

So the work runs on windows. Shallow draft barges come in on the flood, set up while there is water under them, and the lifting happens inside the hours when the platform is stable and the wind is inside limits.

Miss the window and the next one is roughly twelve hours away, which is why an installation clock here is measured against a tide table rather than a calendar.

Deep water gives a jack up. Shallow water gives a schedule.

What is being installed and by whom

The project is 16 machines for 128 megawatts, split across two phases of 48 and 80.

The turbine is a unit with a rotor spanning 741 feet and rated above 8 megawatts, supplied by a Chinese manufacturer for which this is a first installation outside its home market.

The developer is a Vietnamese group. The first turbine went up on the 16th of September and full grid connection is targeted for next month.

Five months passed between contract signature and the first equipment arriving on site, which is fast for an offshore scope of this size.

Rainfall and strong winds ran through the installation period, and the region sits in a typhoon track, so neither was a surprise.

Sixteen machines, two phases, one month.

The claim that needs trimming

This is being described as Vietnam’s largest nearshore wind farm. That is not the claim the supplier actually made.

What was said is that these are the largest single turbine units among nearshore projects in Vietnam and south east Asia. The record belongs to the machine, not the project.

The distinction is not pedantic. Vietnam’s southern coast already carries nearshore capacity built out in the years around the feed in tariff deadline, in blocks that add up to more than 128 megawatts.

What is genuinely new is putting a machine of this class on a tidal flat at all, because until recently the units used here were a third of the size.

Biggest turbine, yes. Biggest farm, no.

What one machine every five days actually requires

The interesting number in this project is not the megawatts. It is the drop from seven days to five between the first unit and the second.

That improvement is almost entirely rehearsal. A crew that has done the sequence once knows which lift order works with the tide and where the setup time was being lost.

It also depends on components being staged ashore in the right order, because a tidal window is no use if the part it was booked for is at the back of the yard.

That staging logic is the same one behind five turbine sets loaded in port at a time in the North Sea.

The phases, the turbine model and the installation times are reported by an offshore title.

Seven days, then five, fourteen to go.

What a tidal site costs after the crews leave

Installation is the visible half. Service is the half that runs for twenty five years and nobody films it.

Every maintenance visit faces the same constraint the build did. A technician reaches the tower inside a tidal window or not at all, and an unplanned fault does not wait for the water.

Salt and humidity are the other standing cost. Coatings, bolt tension and electrical enclosures all age faster here than they would in a dry climate, and a delta adds abrasive silt to the mix.

The supplier’s answer is a lighter machine with maintenance access designed in, which is the right answer if it holds up.

Scale is arriving across the region, with neighboring markets standing up a first plant of their own.

The regional record, the commissioning target and the phase split are set out by a construction title.

A wind farm on a tidal flat answers to the moon for its whole life.