On a summer morning, the tide is slowly receding from the coastal tidal flats of Huanghua, Cangzhou City, Hebei Province in northern China, as rows of photovoltaic panels shimmer in the sunlight. Clean electricity generated by the panels is continuously fed into the grid, while a gentle breeze ripples across the water beneath them, where fish and shrimp swim freely in vibrant aquaculture areas.
The Guohua Energy Investment Green Port Hydrogen City project
Not far away, Phase I of the Green Ammonia Project, part of CHN Energy's first flagship hydrogen-based green fuel project, Green Port Hydrogen City, has been completed and handed over for commissioning, entering the stage of integrated commissioning and feedstock trial runs. In the future, the project will leverage renewable electricity resources to build a flagship application of large-scale green hydrogen, ammonia and methanol production through a zero-carbon industrial model covering the full chain from green electricity to green hydrogen to green ammonia.
How can tidal flats meet multiple new expectations?
Huanghua borders the Bohai Sea and is endowed with abundant wind and solar resources as well as extensive coastal tidal flats. Despite these rich natural resources, development and utilization present significant challenges. CHN Energy Guohua Energy Investment is developing the Green Port Hydrogen City mega-base project here, comprising 1.09 million kilowatts of photovoltaic capacity, 400,000 kilowatts of wind power capacity, and a synthetic ammonia production facility with an annual capacity of 100,000 metric tons. The photovoltaic component is one of China's largest fishery-photovoltaic-complementary projects, while the synthetic ammonia component adopts China's first flexible synthetic ammonia technology capable of operating across multiple steady states.
The project first had to address ecological challenges. Covering approximately 26,500 mu (1,766.7 hectares), the project site has severe soil salinization and a fragile ecosystem. If conventional photovoltaic panels were simply installed across the site, electricity could be generated above the panels while the space below remained unused; prolonged shading could also exacerbate soil compaction and salt accumulation. Local aquaculture faces its own difficulties: open-air farming is highly vulnerable to high temperatures and disease, with losses exceeding 10 percent during extreme summer weather. For fish farmers, the key question is not how many photovoltaic panels can be installed, but whether the project can genuinely improve water quality and increase their income.
The photovoltaic array of the Guohua Energy Investment Green Port Hydrogen City project
An even greater challenge is the consumption of renewable electricity. Once completed, the project is expected to generate approximately 1.83 billion kilowatt-hours of electricity annually. However, wind and solar power are inherently variable and intermittent, with fluctuations ranging from 30 percent to 50 percent, placing pressure on the grid to absorb large amounts of renewable power. Synthetic ammonia production, meanwhile, is a continuous industrial process requiring a stable energy supply. Conventional synthetic ammonia facilities have relatively slow load-adjustment rates, making it difficult for them to respond to rapid changes in wind and solar output.
On one side are the practical demands of ecological protection and increased local incomes; on the other are the urgent needs to develop a large-scale renewable energy base and maximize the consumption of green electricity. Rather than addressing these challenges separately, Guohua Energy Investment has sought solutions by considering land, fisheries, electricity, hydrogen and chemicals as parts of a single integrated system.
How can photovoltaics create new space for aquaculture?
"At first, everyone was thinking about how to minimize the impact of photovoltaic panels on aquaculture," said Guo Kaimin, the project manager. But research showed that the main challenge facing Huanghua's aquaculture industry was actually excessive summer sunlight and high water temperatures. This led to a shift in approach.
Data show that photovoltaic panels can reduce intense solar radiation by more than 35 percent, helping curb excessive growth of harmful algae. They can increase water transparency by 20 percent to 25 percent, reduce the incidence of aquatic diseases by more than 30 percent, raise the survival rate of aquatic products by 15 percent to 20 percent, and increase overall economic returns from aquaculture by approximately 18 percent.
"The space beneath the photovoltaic panels is not idle space. It is ecological space that can create additional value," said Wang Zhizheng, deputy manager of the wind power project department.
The project team has repeatedly optimized panel installation parameters, monitored changes in the aquatic environment and assessed the adaptability of different aquaculture species, seeking to develop a three-dimensional integrated model combining power generation above and aquaculture below. Row upon row of photovoltaic panels serve not only as clean energy facilities but also as sunshades that regulate the microenvironment of the aquaculture waters. Photovoltaics are no longer simply about covering the water with panels to generate electricity; they have become an important vehicle for improving the ecological environment and promoting industrial integration.
How can a green city open a new chapter in clean development?
From the coastal tidal flats of Huanghua, the blue sky, the blue sea, photovoltaic arrays and aquaculture waters form a harmonious landscape. According to estimates, the Green Port Hydrogen City project will generate approximately 1.83 billion kilowatt-hours of electricity annually, enough to meet the annual electricity needs of about 2.74 million residents. Compared with coal-fired power plants, the project can save approximately 520,400 metric tons of standard coal and reduce carbon dioxide emissions by approximately 1.44 million metric tons each year, while cutting emissions of sulfur dioxide, nitrogen oxides and other air pollutants by hundreds of metric tons. During construction, the project provided local employment for nearly 2,000 workers. Once operational, it will also create long-term positions in areas such as professional technology and operations and maintenance. The green energy project will bring not only cleaner electricity, but also more employment opportunities, more resilient industrial chains and more sustainable space for development.
Engineers on site commissioning an ammonia compressor
Starting from a stretch of saline-alkali tidal flats, Guohua Energy Investment is building more than a wind and solar power station or a chemical facility in isolation. Instead, it is creating an integrated solution rooted in local resources, responsive to ecological needs and designed to promote industrial synergy.
Above the photovoltaic panels, green electricity connects thousands of households; beneath them, ecological aquaculture creates new vitality; and along the production chains for hydrogen and ammonia, green electricity is transformed into green energy that will power industries of the future.
