Wind power is not free. To use it, we must give up other goods and services to build wind turbines and transmission lines.

Wind turbines can produce electricity only when the wind is strong enough, but advances in technology are enabling turbines to operate in lower wind conditions.

Some of the best wind farm locations are far from major population centers, so transmission lines can be long and power losses large.

If we produced most of our electricity using wind power, we would be operating inside the PPF at a point such as Z.