[myrmidon]

You need ~4 strikes per hour to keep up with a single large offshore wind turbine (15MW at 40% capacity factor).

That would mean 350km² just to match a single wind turbine (at 100% capture efficiency for 5GJ lightning strikes).

This is not ever gonna make economical sense.

[nomilk]

True that an offshore wind turbine can produce 15MW. But it can cost $100m+ just for 1 turbine (built and installed). If drones are going up anyway (to protect a city/citizens from strikes), then electricity generation is effectively free, and the marginal cost is equal to the hardware required to capture it (maybe relatively low).

[myrmidon]

You don't just need to cover the 350km² with drones though, you also need buffering and/or transmission capabilities for absurdly high amounts of power (=> but low amounts of energy).

If you wanted a single buffer for the whole 350km², you'd need transmission capability from any point (or any drone launch station) to your central buffer in the Terawatt range (currently our highest power grid links are in the ~10GW range, so this is pure fantasy already). Utilization (~ capacity factor) for the lighting capture infrastructure would also be abysmally low. You'd basically need to build a ~10TW (generous estimate!) system, where costs in a lot of components directly scale with power, just to get ~10MW of sustained power out.

There is no way you are ever gonna compete with that $100M wind turbine; you could literally have cheap, high-field, room temperature superconductors and be gifted several warehouses worth of supercapacitors, and the whole lighning capture boondoggle still would not make any economic sense.

[sightbroke]

Are conditions for lightning less frequent than wind?

Every wind turbine generates power while there is wind.

Will a large percentage of drones & energy capture devices be of use while there is lightning?

[NikkiA]

Wind turbines work from about 5 km/h and up winds, so yes, much more frequent than lightning.