How do you compare the environmental impacts of wind turbines with other renewable energy sources?

1 What is LCA?

LCA is a tool that helps you measure and compare the environmental impacts of different products or systems throughout their life cycle. A life cycle includes all the stages from raw material extraction, manufacturing, transportation, installation, operation, maintenance, and disposal or recycling. LCA considers various environmental aspects, such as energy use, resource consumption, emissions, pollution, and biodiversity. LCA can help you identify the hotspots of environmental impacts, the trade-offs between different impacts, and the opportunities for improvement.

2 How are wind turbines assessed?

Wind turbines are assessed by applying the LCA method to their components, processes, and outputs. The main components of a wind turbine are the rotor, the nacelle, the tower, and the foundation. The processes include the production of materials, such as steel, concrete, fiberglass, and rare earth metals, the fabrication and assembly of components, the transportation and installation of the turbine, the operation and maintenance of the turbine, and the decommissioning and recycling or disposal of the turbine. The outputs include the electricity generated by the turbine, the emissions avoided by displacing fossil fuels, and the potential environmental impacts of the turbine on the surrounding ecosystem.

3 What are the main environmental impacts of wind turbines?

The main environmental impacts of wind turbines can be grouped into four categories: greenhouse gas emissions, land use, water use, and waste generation. Greenhouse gas emissions are the gases that contribute to global warming and climate change, such as carbon dioxide, methane, and nitrous oxide. Land use is the area occupied by the turbine and its infrastructure, such as roads and cables. Water use is the amount of water consumed or withdrawn for the production and operation of the turbine. Waste generation is the amount of solid or hazardous waste produced or disposed of by the turbine.

4 How do wind turbines compare with other renewable energy sources?

Wind turbines compare favorably with other renewable energy sources in terms of greenhouse gas emissions, water use, and waste generation. According to a meta-analysis of LCA studies, wind turbines have a low life cycle greenhouse gas emission intensity of 11 g CO2eq/kWh, which is much lower than fossil fuels (465-1000 g CO2eq/kWh) and comparable to solar (18-45 g CO2eq/kWh), hydro (17-80 g CO2eq/kWh), and biomass (18-230 g CO2eq/kWh). Wind turbines also have a low life cycle water consumption intensity of 0.4 L/kWh, which is lower than solar (2-12 L/kWh), hydro (10-70 L/kWh), and biomass (40-300 L/kWh). Wind turbines also have a low life cycle solid waste generation intensity of 0.01 kg/kWh, which is lower than solar (0.02-0.1 kg/kWh), hydro (0.02-0.1 kg/kWh), and biomass (0.03-0.2 kg/kWh).

However, wind turbines have a higher land use intensity than other renewable energy sources, due to their large footprint and spacing requirements. The life cycle land use intensity of wind turbines is 5.5 m2/kWh, which is higher than solar (3-5 m2/kWh), hydro (1-2 m2/kWh), and biomass (0.5-1 m2/kWh). Additionally, wind turbines may have some negative impacts on wildlife, such as bird and bat mortality, habitat fragmentation, and noise disturbance.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?