China just built the world's largest floating solar plant: Here's how it works

China has transformed a vast stretch of shallow coastal waters into the world's biggest open-sea solar power facility, capable of powering millions of households.

The HG14 project off Dongying in Shandong province reached full grid connection in late December 2025, marking a leap in offshore renewables.

Developed by Guohua Investment under China Energy Investment Corp (CHN Energy), this gigawatt-scale farm spans 1,223 hectares, about 8 km from shore in waters 1-4 meters deep.

Unlike typical floating arrays on lakes, HG14 uses 2,934 fixed steel platforms, each 60m by 35m, anchored by 11,736 piles, for resilience against winds, waves, tides, and winter ice.

More than 2.3 million solar panels are installed on these platforms. Because the panels are cooled by sea air and receive extra reflected sunlight from the water, they generate 5-15% more power than similar systems on land.

The $1.2 billion venture is China's first gigawatt offshore PV under a national "three-dimensional sea-use rights" policy, preserving farmland while tapping marine space.

Electricity from the solar plant is carried to land through an undersea power cable and sent to a land-based power station. A large battery system installed alongside stores extra electricity and releases it when needed, helping keep supplies steady. This setup increases usable power by about 20% and reduces costs by roughly 15%.

Once it starts running at full capacity, the plant is expected to generate enough electricity each year to supply around 2.6 million homes, covering most of the power needs of the nearby district.

China's "floatovoltaic" push, blanketing waterways, eases its land shortage for solar, which dominates global additions at over 50% yearly.

HG14 exemplifies how offshore setups multiply efficiency via natural cooling, while bifacial tech captures reflected light. Yet challenges persist: maintenance in harsh seas demands robust designs, and marine ecology monitoring is key for replication.

China had earlier switched on a world-first solar thermal power station in the Gobi Desert that is said to be a cheaper and more efficient use of the technology with potential to be scaled up.

As Beijing accelerates renewables to peak carbon by 2030, projects like this blend engineering feats with policy shifts.

By deploying on unused seas, China not only powers growth but redefines solar's frontiers, potentially inspiring global adoption where land is scarce.