Modeling wind turbine-related greenhouse gas payback times in Europe at high spatial resolution

Abstract

An important metric for quantifying the greenhouse gas saving potential of wind turbine types is the greenhouse gas payback time. Previous studies revealed that wind speed and wind turbine size are negatively correlated with greenhouse gas payback times. However, so far, payback times were mostly estimated for wind turbine types with a hub height of less than 100 m and rated power below 2000 kW at coarse spatial resolution. It is unclear if the negative correlation with turbine size continues to hold at greater heights since, in general, the change in wind speed increase reduces with higher altitude. Thus, the hypothesis that the size of more giant wind turbine types is not negatively correlated with greenhouse gas payback times was tested. The main goal was to develop a high spatial-resolution atlas of European greenhouse gas payback times considering the small-scale wind resource variability for 33 generic wind turbine types. The greenhouse gas payback times were estimated by first calculating the average monthly energy yields for the wind turbine types with hub heights from 60 to160 m and rated power from 800 to 4200 kW at a 250 m × 250 m spatial resolution grid. Secondly, the wind turbine types’ anticipated greenhouse gas emissions were estimated based on their hub height and rotor diameter. The wind turbine type-related net greenhouse gas emissions were compared with the mean emissions of a natural gas-fired power plant (0.5 kg CO2,eq/kWh). It was found that wind turbine types with rated power and hub height of {2400 kW, 60 m} and {3600 kW, 80 m} have the shortest greenhouse gas payback times. The European median greenhouse gas payback time was estimated at 6.1 months including the wind turbine types with lowest payback times. In the hub height range of 60 to 160 m, the correlation between greenhouse gas payback times and hub height was found to be significantly positive.