I wonder how high they could be built with present day technology? I guess the limiting factor is the blade, rather than the tower. If you could build wind turbines or solar chimneys several kilometers high, you could easily generate all the energy we need.
This study indicates that we would require "millions" of wind turbines worldwide to supply all energy, by collecting 20% of the wind energy available at 80 m. I did some back of the envelope calculations and I also came up with millions. (It depends on many factors but anyway, the number is not 100,000 or 100 million.) In the US, the number would be roughly comparable to the number of long-haul trucks. Millions of wind turbines around the world would certainly be a blight on the landscape. Strictly from an aesthetic point of view, I would prefer to see a thousand nuclear power plants rather than a million wind turbines. But the wind turbines would probably be cheaper and safer, and less polluting when you take into account pollution from uranium mining and processing.
- Jed
