1. Wind is a diffuse source that requires massive plant to collect any useful amount at an industrial scale.
The U.S. generates more than 4 billion megawatt-hours of electricity annually. At a capacity factor of 25%, that would require at least 1,826,500 megawatts of installed wind capacity. That's more than 27 times the amount currently installed. And it would require the use of more than 170,000 square miles mostly of currently open and wild land.
2. Wind is intermittent and highly variable.
But because the wind doesn't blow steadily at that average rate – let alone in response to actual demand – you'd probably need 3 or 4 times that much, with thousands of miles more of new high-capacity powerlines, to ensure some regular supply. Even then, you'd need complete backup to prevent brownouts if not outright blackouts.
And then there's increased electricity consumption to be considered, especially with charging electric cars and fuel cells.
When the Sleeper Wakes
AWEO