On Birds

Wind turbines sometimes come under criticism for killing birds. While it is true that wind turbines kill some birds, the average turbine kills about 2 birds per year. This number needs to be kept in perspective. For ecologists, it isn’t the death of an individuals that matters – all living things will die someday. It is the impact on populations that matters. A recent story on the possible impact on birds in the US Gulf of Mexico from the BP oil spill may help to provide perspective.

A Toronto Star article quoted Greg Butcher, national director of bird conservation for the Audubon Society, who said that in all, 1 billion birds could be threatened by the spill, which now covers an area the size of southern Ontario. So how many turbines could be built with the same impact on birds, and how much of our electricity would it supply?

If wind turbines last for 20 years, and kill 2 birds per year, you could build 25 million wind turbines and have the same impact. 25 million wind turbines would be about 50 million MW of capacity, and would produce 131,000 million MWh/year, or 131,000 TWh per year. (50,000,000 MW X 30% capacity factor X 365 days X 24 hours) North American demand for power is 4000 TWh per year. So that many turbines can produce about 45 times the total power consumption of the entire continent for 20 years. Put it another way – for 45 times less bird deaths than one oil spill, the continent can have its entire electricity supplied by wind for 20 years.

The BP well looks like it is spewing about 100,000 barrels/day – enough to supply less than 1/2 of 1% of North America’s oil demand.

When we look at our energy sources, we must always remember that all sources have an impact on the environment. And we should choose those that minimize the impact wherever possible.

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