Construction at the world’s largest offshore photovoltaic power station has officially begun in Dongying, China’s eastern Shandong province.

The State-Owned Assets Supervision and Administration Commission of the State Council yesterday announced that Power Construction Corporation of China has started constructing its one-gigawatt fixed pile foundations offshore PV power station in the Port of Guangli, the world’s first to achieve the one-gigawatt threshold.

The project is expected to generate 1.78 billion kilowatt-hours of electricity per year when completed, equal to cutting consumption of 594,500 tons of standard coal, thus reducing carbon dioxide emissions by more than 1.4 million tons.

There are two types of offshore PV power stations, those with fixed pile foundations and those with surface floating. Surface floating PV power stations are built in deep waters and are not destructive to the water quality.

China’s first fixed pile foundation offshore PV power station began operation in May in Wendeng, Shandong province. It was jointly built by PowerChina and State Power Investment Corporation Shandong Energy Group.

Offshore PV power stations are more environment-friendly, cheaper, and take less time to build than land PV power stations. Moreover, they are 15 percent to 30 percent more efficient in electricity generation than land PV power stations thanks to the fact that the water surface has a higher refractive index and is warm in winter and cool in summer.

SPIC Guangdong Electric Power is promoting surface floating offshore PV power stations, considering that offshore PV power stations will gradually move to deeper and more open seas, a staffer at the firm told Yicai. Fixed pile foundation offshore PV power stations must be deep, so they have higher requirements on the seabed and costs in terms of pile drilling, the staffer added.

The biggest challenge for offshore PV power stations is how reliable PV modules are, said Li Qicong from the China Electronics Standardization Institute. For example, PV modules need to be wind-resistant enough in case of strong wind and waves, he noted.

Moreover, many industry insiders brought up the issue of the service life of offshore PV modules, as they need to resist seawater erosion.