3 ms·

8MWh is equivalent to a few hours of electricity generation of a wind turbine.

nomilk 1y 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 https://forum.lowyat.net/topic/5376210/all
- myrmidon 1y ago
  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 1y ago
    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).
    - sightbroke 1y ago
      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 1y ago
        Wind turbines work from about 5 km/h and up winds, so yes, much more frequent than lightning.
    - myrmidon 1y ago
      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.
wiz21c 1y ago
I thought it was muuuuuch more than that! I've learned something otday!

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 https://forum.lowyat.net/topic/5376210/all

myrmidon 1y ago
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 1y ago
  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).
  - sightbroke 1y ago
    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 1y ago
      Wind turbines work from about 5 km/h and up winds, so yes, much more frequent than lightning.
  - myrmidon 1y ago
    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.

wiz21c 1y ago

I thought it was muuuuuch more than that! I've learned something otday!