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Comment by nomilk

15 hours ago

Kuala Lumpur gets (generous assumption) about 100 lightning strikes per square kilometer per year [0].

If a single drone could service a lot of square km, then it could conceivably collect a lot of electricity. E.g. if it could service 20 square km: 20 * 100 * 8mWh = 16gWh per year. Not bad, but an upper bound, and it hinges a lot on that first parameter (service area).

[0] https://forum.lowyat.net/topic/5376210/all

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.

  • 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).

    • 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.

    • 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?

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