An industrial-scale Wind Ladder would be interesting just to test the limits of technology.

- Far offshore, deep water.
- One mile altitude.
- 20 inflatable turbine units in series.
- Tether technology, a la space elevator.
- Climber technology.

Each inflatable unit might be the size of the Hindenburg, and be a real airship in its own right, able to detach from the wind ladder superstructure and fly to a land-based hanger for maintenance. Each one could have its own built-in water condenser/electrolyzer so it can produce hydrogen for buoyancy. Self-contained. Self inflating. That would reduce the need for maintenance every few months due to gas leaks. Collecting sufficient moisture from the atmosphere to electrolyze into hydrogen for buoyancy indefinitely would be quite feasible.

The Magenn website indicates that their 10kW inflatable turbine units contain 32,000 cubic feet of helium, and have a leak rate of 0.5% per month or 160 cu ft/month. Scaling up directly to a 5 Mw inflatable unit we get the following:

5 Mw unit = 80000 cu ft/month leak rate Helium.

However, if we assume that hydrogen will leak twice as fast because it has half the molecular weight, we get the following:

5 Mw unit = 160,000 cu ft/month leak rate Hydrogen
5 Mw unit = 1.75 liters per second hydrogen at STP.
5 Mw unit = 0.078 moles of H2 per second.

Electricity can break the chemical bonds of water and produce hydrogen, a process known as electrolysis.

986.8 kJ/mole H2O bond energy

For the rate that hydrogen would be leaking, we would need 76,970 watts of bond energy to split water into hydrogen. If an electroyzer works at 30% efficiency, each unit would need 256,568 watts total power for the electrolyzer. This is roughly 5.1 percent of rated power for the 5-Mw inflatable wind turbine.

But the water has to be condensed out of the air before it can be electrolyzed. To get sufficient hydrogen each unit would have to condense:

0.078 moles H2O per second, or
1.404 grams H2O per second, or
0.001404 liters H2O per second

An off-the-shelf dehumidifier will remove 1 pint (0.4732 liters) of H2O from the air every 24 hours using approximately 12.77 watts of power. That is about 5.477e-6 liters of H2O per second at that power level. Scaling up to extract 0.001404 liters of H2O per second from air would require a 3274-watt dehumidifier. That's about 0.065 percent of rated power for an inflatable wind turbine.

So, in total each wind turbine would only sacrifice 5.165 percent of rated power to maintain buoyancy indefinitely. The Magenn unit would need to be re-inflated every 4-6 months, but it seems quite feasible that it wouldn't need maintenance of this type if it were so designed. Obviously there are people who prefer the KISS (keep it simple, stupid) approach. But IMO this would be acceptable complexity.