Emergy-based ecological footprint analysis of a wind farm in China

Abstract

Wind power generation has always been considered as clean energy, according with national ecological civilization construction and responding to climate change. However, from the perspective of resource conservation, wind farms directly or indirectly occupy a large amount of land resources along the entire life cycle. Based on the emergy analysis, this paper estimates the ecological footprint of a wind farm in Dalian, evaluates its sustainability, and analyzes the ecological footprint of the four phases which include wind turbines production and transportation, construction, operation and maintenance, and demolition during the life cycle of the wind farm. It was concluded that the emergy carrying capacity of the wind farm was 3879.57 hm2/a, and the emergy ecological footprint was 5117.59 hm2/a. The wind farm was in an ecological deficit. Among the four phases, the ecological footprint of construction was the largest (60.93%), wind turbines production and transportation phase (33.77%) took the second, followed by operation and maintenance (4.59%) and demolition (0.71%). The main contribution of the materials was steel, followed by concrete, ecological protection investment, fiber glass, land occupation and epoxy resin. Finally, in order to illustrate the way to achieve sustainable development of the wind farm, uncertainty analysis and scenario analysis were carried out. It was found that when 62% of the recycled materials were used for wind turbines production, the wind farm realized ecological balance. Reducing the solar transformity (UEV) of steel and concrete can also decrease the ecological footprint of the wind farm.