Siemens Wind Power and Renewables has published four new Environmental Product Declaration (EPD) brochures, each representing one of the company’s four product platforms, covering both geared and direct drive wind turbines for offshore and onshore projects. The figures are based on Life Cycle Assessments (LCAs) of four defined wind power projects: two offshore wind plants with 80 wind turbines, and two onshore wind projects with 20 wind turbines. The new brochures offer valuable figures of the environmental performance of Siemens’ products.

Central to LCAs is the energy payback time calculation -- the length of time the wind power plant has to operate in order to produce as much energy as it will consume during its entire lifecycle. For instance, In an onshore wind power plant with an average wind speed of 8.5 meters per second, the energy payback time of a Siemens SWT-3.2-113 wind turbine is 4.5 months. This figure is based on a 20-turbine project, including a 13 kilometer grid transmission connection, and all the efforts involved covering material use, manufacturing, installation, operation and maintenance as well as dismantling and end-of-lifetime treatment.

The offshore Life Cycle Assessment based on a project with 80 Siemens D6 wind turbines shows another interesting environmental performance: During its estimated lifetime, it produces 53 million mWh and saves 45 million tons of CO₂, which is equal to the amount of CO₂ absorbed by a forest with an area of 1,286 km2 over 25 years. This figure corresponds to a CO₂ emission of only seven grams per kilowatt-hour (g/kWh) compared to the 865 g/kWh found with average global fossil power production.

The EPD brochures on the four Siemens Product Platforms (G2, D3, G4 and D6) are now available for download.