Makani Power: the windmill that isn’t

I once saw a documentary about skyscrapers where the architect says, “It’s not that hard to make a 100 story building. You just need to make a one story building 1500 feet up in the air, and the rest is easy.”

Sometimes it’s easy to miss where the real work is.

Makani Power is a windmill company that builds only the business end of the windmill. The rest of it, overpaid and redundant, gets chucked. Think about it this way. A windmill (or turbine) is a great big propeller blade that’s being pushed by the wind. You want to build an efficient wind turbine, here’s what you need to do: Make it big (large diameter blade) and stick it in the wind (duh). Now look at the problem we’ve got. The best winds are way up high, and large diameter blades are heavy. So you’ve got to build a massive tower to carry the load of a giant spinning blade.

But wait: we went to all that trouble to put the spinning tips of the turbine far apart and up in the wind. Can’t we just leave out everything else? Then we would only need a tiny fraction of the materials to achieve the same result.

THAT is the thing that Makani Power did. They made the spinning tip of a turbine and almost nothing else. More kite than windmill, it’s actually a tethered airplane with reverse motors. By “reverse motors” I mean they look like regular airplane propellers, but they generate power instead of using it up. Clever, eh?

A clever concept is a small part of the battle. That and a ton of engineering might just add up to something useful. They seem to be making good progress, and I wish them luck.

Here’s how it’s supposed to work commercially, and here’s what it looks like now.