Carbon footprint and carbon emission intensity of grassland wind farms in Inner Mongolia

Abstract

Greenhouse gas emissions are the primary cause of global warming, and active development of renewable energy has become popular in resource utilization. Wind power, as the second largest renewable energy source, plays an important role in the power industry, and clarifying the carbon footprint and carbon emission intensity of wind farms is the basis for their rational use. Although the study of the carbon footprint of wind farms has attracted considerable attention, the characteristics of the carbon footprint and carbon emission intensity of wind farms in grassland areas compared with other types of wind farms have not been determined to date. As an important part of the world's largest Eurasian grassland, the installed capacity of wind farms in the grasslands of Inner Mongolia ranks first in China. In this study, the carbon footprint of the production, transportation, construction, operation, and disposal stages was evaluated by using the life cycle assessment method in a 49.5 MW wind farm in the Inner Mongolia grassland, and its carbon emission intensity was explored in depth. The results showed the following: (1) The carbon footprint of the wind farm in the grassland area was 18701.29 t, of which the construction stage accounted for the largest proportion at 56.74%, and the other stages, ranging from highest to lowest, were production, disposal, transportation, and operation stages, which were 28.18%, 12.08%, 2.76%, and 0.24%, respectively. (2) The carbon footprint of material recycling was 18726.53 t, and the reduced carbon emissions accounted for 50.03% of the total carbon emissions. (3) The carbon emission intensity of the wind farm was 6.57 g/kWh, which is approximately 148.45 times, 72.91 times, 127.85 times, and 3.50 times less than the carbon emission intensity of the four non-renewable energy sources of coal, natural gas, oil, and nuclear power, respectively. (4) Wind power have lower carbon emission intensities than the four renewable energy sources of hydropower, biomass, and photovoltaics. This study highlights the very important role played by system boundaries when employing life cycles to evaluate carbon footprints. Compared with offshore wind farms and non-grassland wind farms, grassland wind farms have the lowest carbon emission intensity. The promotion of wind farms has excellent potential in grassland areas.