In a striking symbol of energy transition, the Chinese city of Huainan—once synonymous with coal mining—now hosts the world’s largest floating solar power station, perched atop a flooded former coal mine. With a capacity of 40 megawatts (MW), this state-of-the-art photovoltaic system is reshaping both landscapes and mindsets by transforming environmental liability into renewable opportunity.

The Rise of Floating Solar on a Coal Legacy

Commissioned in May 2017, the Sungrow Huainan Solar Farm spans approximately 86 hectares over a subsided mining basin, employing around 120,000 to 166,000 solar panels to deliver enough energy for roughly 15,000 homes. The array floats over a manmade lake, created through the collapse of coal mining operations—a testament to repurposing land once deemed environmentally degraded.

Engineering Floating into Function

Floating solar farms offer unique advantages: water cooling enhances efficiency, panels stay cleaner with less dust, and evaporation from the water surface is significantly reduced. To protect against wear and environmental stress, Sungrow reinforced the floats with more than 1,000 concrete piles, ensuring stability even as water levels vary. The facility is built to last—engineered to resist heat, humidity, and mineralization—promising a lifespan of 25 years. Even drones patrol the site, providing surveillance and aid in maintenance.

Voices from Below to Above

One former coal miner-turned-maintenance electrician, Sang Dajie, contrasts his old life underground with his new reality:

“The coalmine was very hot and the air was bad… But here I feel safe. The new energy is safe.”

He now works on a floating solar grid instead of toiling beneath the earth—a powerful metaphor for change.

A Symbol of China’s Clean Energy Pivot

Huainan’s floating solar installation is more than an isolated engineering feat—it marks a broader shift. The project underscores China’s transition from coal dependency toward clean energy leadership. In 2017, just as the station went live, China began halting the construction of over 100 coal-fired plants, signaling a significant strategic redirection. The solar farm’s placement atop a former coal mine paints a vivid narrative of environmental redemption.

Contextualizing Floating Solar’s Growth

While Huainan held the title of world’s largest floating solar farm in 2017, the sector has rapidly evolved. Global floating photovoltaic (FPV) capacity surged from around 1 GW in 2018 to 13 GW by 2022, with China maintaining leadership in many of the largest installations, including Dezhou’s 320 MW FPV plant.

Yet back in 2017, Huainan’s 40 MW represented a milestone. The prior global record stood at just 6.3 MW in the UK—an order of magnitude smaller.

Challenges and Future Potential

Floating solar presents both promise and challenges. Installation and maintenance costs are typically 15–25% higher than land-based systems, due to the complexities of buoyancy and water environments. Nevertheless, the energy efficiency gains, land preservation, and water conservation benefits often balance out over a system’s lifespan.

Huainan’s success illustrates how degraded industrial zones can be reclaimed for sustainable infrastructure—offering a model for post-industrial revitalization worldwide.


Conclusion

The floating solar station in Huainan stands as a poetic and practical revolution: a tangible repudiation of coal’s legacy and a powerful embrace of solar’s promise. It demonstrates how innovation, when rooted in reinvention, can rewrite landscapes and futures—turning the scars of extraction into beacons of renewal.