Siemens has conducted a review of its wind turbine technology to determine the actual environmental impact of wind energy, from manufacturing through construction and operation. The company’s study found that both onshore and offshore “showed outstanding results.
In a post on its website, Germany multinational Siemens announced the results of a “detailed ecological review of its wind turbines.” The study was the result of efforts to maintain “a high degree of transparency” for its customers and the authorities, and was aimed at reviewing “the actual benefits of green power for the environment.” Many critics of wind energy (of which there are not many) often attempt to highlight supposed inadequacies in the manufacturing process which they say belittles the supposed environmental benefits resulting from the operation of wind turbines. Siemens study, however, puts the lie to this suggestion.
The study investigated two offshore wind farms comprising 80 turbines, and two onshore wind projects comprising 40 turbines.
The initial findings are that land-based wind farms pay off faster than their more powerful-yet-construction-intensive offshore cousins.
Specifically, offshore wind farms with 80 turbines produces 53 million MWh of electricity during its intended 25-year lifespan. Said wind farm emits seven grams of CO2 per KWh, whereas, in comparison, fossil fuel energy sources produce an average of 865 CO2 per KWh, leaving wind farms saving an average of 45 million tonnes of CO2. To absorb that much CO2, you would subsequently need approximately 1,286 square kilometres of forest in Central Europe.
In terms of how long it takes for an onshore wind farm to account for the volume of energy it consumes over its lifespan, Siemens study found that at an average wind speed of 8.5 metres per second, it would only take between 4.5 and 5.5 months. What’s most impressive about this figure is that it takes into account materials, production, construction, operation, maintenance, dismantling, and recycling into account — which is to say, every feasible aspect of a wind farms lifespan is accounted for in under 6 months.
Offshore wind farms take a little longer … between 9.5 and 10.5 months.