Optimal Environmental Siting of Future Wind Turbines in the North Sea.

Offshore wind energy (OWE) represents a key technology for achieving a sustainable energy transition. However, offshore wind farms (OWFs) can impact the environment via installation, operation, maintenance, and decommissioning activities together with the raw materials and energy required for their manufacturing. This study assesses the material and carbon footprint of potential OWF locations in the North Sea for various possible future technology developments. We find that better sitings could save up to ∼0.11 kg (∼65%) of steel, ∼ 0.16 g (∼31%) of copper, and ∼6.44 kg (∼26%) of embodied CO-eq per MWh of electricity produced compared to the status quo setups. Nearshore regions of the North Sea, particularly the eastern and northwestern areas, have the lowest CO-eq per MWh of electricity produced due to favorable wind resources. Developing an OWF in the central North Sea requires more copper and aluminum due to large distances to shore and thus incurs higher embodied CO-eq per MWh. These areas also overlap with several protected areas and thus remain the least favorable for OWE development. The future emergent OWE technological developments for 2040 such as the installation of larger turbines with an extended lifetime alone could, on average, lead to reductions of ∼0.06 kg in steel demand (∼35%), ∼ 0.15 g in copper demand (∼31%), and ∼10.97 kg of CO-eq (∼41%) per MWh produced. Future OWFs incorporating these technological developments, when placed in the most suitable locations, have the potential to substantially lower OWF environmental impacts across the full turbine life cycle.