Comparison of life-cycle environmental impacts of onshore and offshore wind farms during the southward movement of wind power development in China

Serious wind curtailment occurred in the Three North region in China around 2015; since then, wind power development has been moving southward. Wind resource and wind turbine technology variations would affect the environmental impacts of wind farms during this process. Here, we applied the life cycle assessment method to examine the environmental performance of wind farms during the southward movement using a comparison of six case wind farms that included one onshore farm in Inner Mongolia, three onshore farms in Shandong, and two offshore farms in Jiangsu. The results revealed that the onshore farms with larger stand-alone capacity (2 MW) in Shandong (with a life-cycle greenhouse gas emissions of 6.8–7.6 g CO₂-eq/kWh) performed worse than the farm (1.5 MW) in Inner Mongolia (6.5 g CO₂-eq/kWh) because of their lower annual utilization hours. Only the offshore farms also with larger stand-alone capacity (4.0–5.9 g CO₂-eq/kWh) performed better than the farm in Inner Mongolia. These results suggest that wind turbine technological progress can offset wind resource weaknesses to a certain degree theoretically during the southward movement process. However, during practical operation, they all suffered from wind curtailment whether they were closer to the load center or not. Various measures to promote the green development of the wind power industry were proposed that included increasing the electricity consumption capacity and combining energy storage technologies. Finally, our results revealed that high-capacity turbines and offshore wind power could be prioritized when developing new wind farms during the southward movement process in China.