China installs world's largest offshore converter station off Guangdong

Overview

Updated Oct 24

Power is flowing from the world's largest offshore converter station, roughly 100 kilometers off Guangdong's coast. On September 27, the first five turbines at the Qingzhou V and VII wind farms began sending electricity through the 25,000-tonne Heart of the Sea Wind station, which converts it to ±500-kilovolt direct current for the trip ashore.

The station gathers power from 163 turbines, raises the voltage and converts it to direct current, which loses far less energy than alternating current over long submarine cables. At full output the project is expected to send about 6 billion kilowatt-hours a year to the Guangdong-Hong Kong-Macao Greater Bay Area. That works out to nearly 5 million tonnes of carbon dioxide avoided annually, according to China Three Gorges Corporation.

Why it matters

Deep-sea wind power now reaches Guangdong without losing most of its energy — up to 6 billion kWh a year along that line.

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Key Indicators

25,000 tonnes

Weight of converter station

The upper structure alone weighs 25,000 tonnes, requiring a float-over installation because no domestic crane could lift it.

2,000 MW

Transmission capacity

First ±500 kV, 2,000 MW flexible DC offshore converter station in the world.

6 billion kWh/year

Annual power delivery at full output

Clean electricity expected to reach the Guangdong-Hong Kong-Macao grid each year once all turbines are online.

1,090 nautical miles

Sea voyage from Nantong to Yangjiang

The station was carried on a semi-submersible vessel from Jiangsu province to its final site.

90 km

Farthest distance offshore

The Qingzhou V and VII site sits up to 90 kilometers from land, in water as deep as 53 meters.

163

Wind turbines served

The station collects power from turbines across the Yangjiang Qingzhou V and VII offshore wind farms.

Turbines connected to the grid

China Three Gorges connected the first five Qingzhou turbines on September 27, 2026.

Voices

Curated perspectives — historical figures and your fellow readers.

People Involved

Huang Yong (黄勇)

Project engineer, China Three Gorges Corporation Guangdong branch

Led installation engineering for the 'Heart of the Sea Wind' station

Yang Kun (杨昆)

Executive vice chairman, China Electricity Council

Commenting on China's offshore wind leadership

Gu Pengcheng

Engineer, China Three Gorges Corporation Yangjiang branch

Led commissioning and grid connection of the first five Qingzhou turbines, connected September 27, 2026

Organizations Involved

China Three Gorges Corporation

State-owned energy developer

Project owner of Qingzhou V and VII; first batch of turbines connected to the grid

State-owned energy giant that operates the Three Gorges Dam and now develops the world's largest offshore wind projects.

Guangdong Electric Power Design Institute (GEDI)

Engineering, procurement, and construction contractor

EPC contractor for the converter station

Engineering subsidiary of China Energy Engineering Group that designed and built the converter station under an EPC contract.

China Classification Society (CCS)

Marine classification and inspection body

Inspection authority for installation

Marine classification society that inspected the jacket installation, float-over operation, and leg mating unit welding.

Timeline

May 2026 October 2026

7 events Latest: October 12th, 2026 · 1 month ago

Tap a bar to jump to that date

October 2026
Energy China details the project's world-first list
Latest Disclosure

EPC contractor Energy China GEDI described the scheme as a ±500 kV/2,000 MW flexible DC link with 66 kV collection cables and the first application of ±500 kV DC submarine cable.
October 12th, 2026
Station settled in place off Yangjiang, commissioning continues
Milestone

State media confirmed the structure is fully positioned in the Qingzhou sea area; it will deliver about 6 billion kWh of green power yearly once operational.
October 4th, 2026
September 2026
First five turbines connect to the grid
Milestone

China Three Gorges connected the first five Qingzhou V and VII turbines to the grid through the Heart of the Sea Wind station. At full capacity the project is expected to deliver about 6 billion kWh a year to the Greater Bay Area.
September 27th, 2026
July 2026
Station moves to final cabling and testing phase
Milestone

Reports confirmed the station fully installed about 100 km offshore; subsea cable installation and joint offshore-onshore testing began before commercial operation.
July 23rd, 2026
Full offshore installation declared complete
Verification

China Classification Society confirmed the leg mating unit welding finished, completing all offshore structural work.
July 6th, 2026
June 2026
Float-over installation completes with millimeter precision
Installation

After seven hours of positioning, the station's eight insertion spikes locked into the seabed jacket foundation off Yangjiang, setting six world records.
June 4th, 2026 • 2:18 PM
May 2026
Heart of the Sea Wind departs Nantong
Logistics

The 25,000-tonne converter station left Nantong, Jiangsu province, on a semi-submersible vessel for a 1,090-nautical-mile voyage to Yangjiang.
May 27th, 2026

Scenarios

Heart of the Sea Wind begins commercial operation by mid-2027

Likely Resolves by Q2 2027

Discussed by: CGTN, SASAC, and project disclosures describing the commissioning path

Subsea cables get laid without major setbacks, joint offshore-onshore testing passes, and the station begins feeding the Guangdong grid. China Three Gorges announces grid connection and the first delivered power.

Model replicated: China orders comparable stations for future deep-sea projects

Possible Resolves by Q2 2028

Discussed by: China Electricity Council officials and state media framing the project as a template

Once the technology proves out, Chinese developers order similar ±500 kV flexible DC stations for other far-offshore wind bases, scaling the 10 GW-class Yangjiang build-out and similar projects in the East China Sea.

Commissioning slips into 2028 on cable or integration problems

Unlikely Resolves by Jan 31, 2028

Discussed by: The complexity of the first ±500 kV DC submarine cable plus joint offshore-onshore testing

Faults emerge in the world's first ±500 kV submarine DC cable or in grid synchronization, pushing first commercial power past initial schedules. Station remains installed but idle beyond early 2028.

Historical Context

2 moments from history that rhyme with this story — and how they unfolded.

March 1954

Gotland HVDC Link (1954)

Sweden commissioned the world's first commercial high-voltage direct current (HVDC) link, a 20 MW, 98-kilometer submarine cable connecting the island of Gotland to the mainland. It was built mainly to transmit surplus wind power from the island.

Then

Gotland's wind power became sellable to the mainland, and the technology proved HVDC could cross open water efficiently.

Now

HVDC became the standard for long-distance and submarine power transmission worldwide, with voltages and capacities rising steadily over seven decades.

Why this matters now

The Heart of the Sea Wind is the direct descendant of this first link — same physics, same purpose, but 100 times the voltage and carrying far more power from dozens of turbines.

2009–2012

BorWin1 — First Offshore Wind HVDC Converter (2012)

Germany's BorWin alpha went into service in the North Sea as the world's first offshore wind HVDC converter station, collecting power from the 400 MW BorWin1 and BorWin2 wind farms and transmitting it to the mainland grid.

Then

It proved offshore conversion was technically feasible, opening the North Sea's deeper wind zones to development.

Now

Set the template China has now scaled: collect AC from turbines, convert offshore to DC, and ship it ashore with minimal loss.

Why this matters now

China used the same architecture but built it five times larger — 2,000 MW at ±500 kV versus BorWin's 400 MW — and made all key components domestically.