> Future efforts will focus on developing technologies for capturing and storing lightning energy for potential use (Figure 7).
According to a quick search, a typical lightning strike carries about 1-5 billion joules of energy, equivalent to roughly 250-1500kWh; enough energy to power a typical home for 10-60 days. But larger bolts of lightning can have up to 8000kWh, almost a year's supply of electricity for a home in a single bolt!
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).
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.
Based on this and other comments in this HN thread, harnessing the lightning energy for potential use wouldn't be a replacement for a power plant. However, if the resources for the lightning energy capture are/become too cheap, this could be a replacement for solar panels. Instead of replacing the power plant, it would replace/complement electricity production of a single home/building. Maybe with big enough batteries that can capture this energy, it could become a viable solution?
> Maybe with big enough batteries that can capture this energy, it could become a viable solution?
No, it could not. The problem is that lighning strikes are so short, that their middling amount of energy still results in an insane amount of electrical power (for a very short time). And electrical power is the primary driver of cost in most components here.
Capturing lighning is like building literally a hundred electrical substations just to run them for 50 microseconds a day, 10 days per year. Our planet simply does not have the lighning density for this to ever work out.
All that (very expensive!) capture infrastructure would basically sit uselessly for almost all the time (even in the middle of a lightning storm!).
According to a quick search, a typical lightning strike carries about 1-5 billion joules of energy, equivalent to roughly 250-1500kWh; enough energy to power a typical home for 10-60 days. But larger bolts of lightning can have up to 8000kWh, almost a year's supply of electricity for a home in a single bolt!