The most frequent believability issue I see in “solarpunk” SF is the lack of awareness of how much power you can…

Comments

1. 

   June 28, 2018

   andrew mcmillan

   Their number of 170,000 Wh/kg for jet fuel seems wrong. Later in there they say gasoline is 3 x 1000 Wh/kg which is in line with what I’d read elsewhere. It seems that Lithium-carbon monofluoride has densities as high as 780 Wh/kg, but some of the solid state technologies appear as if they may land in the 1000-2000 Wh/kg range in the next few years.

   I’m not sure if I’ve seen anything on the Wh/kg rating of solar panels, but I can imagine that a lifting body with some combination of solar panels, lighter-than-air cells and energy dense batteries could go a long way towards achieving short-haul commercial flight in ten years.

   The fact that several electric aircraft are now commercially available for 1-2 person flight with 60+ minutes journey capability suggests it really is here for some specific use cases and will just get better from now.

   Reply
2. 

   June 28, 2018

   andrew mcmillan

   Their number of 170,000 Wh/kg for jet fuel seems wrong. Later in there they say gasoline is 3 x 1000 Wh/kg which is in line with what I’d read elsewhere. It seems that Lithium-carbon monofluoride has densities as high as 780 Wh/kg, but some of the solid state technologies appear as if they may land in the 1000-2000 Wh/kg range in the next few years.

   I’m not sure if I’ve seen anything on the Wh/kg rating of solar panels, but I can imagine that a lifting body with some combination of solar panels, lighter-than-air cells and energy dense batteries could go a long way towards achieving short-haul commercial flight in ten years.

   The fact that several electric aircraft are now commercially available for 1-2 person flight with 60+ minutes journey capability suggests it really is here for some specific use cases and will just get better from now.

   Reply
3. 

   June 29, 2018

   Isaac Kuo

   I wonder if in-flight towing could solve the problem even without major battery advances. The client aircraft has only a small battery…for the most part it’s a glider. It spends most of its time being towed by a succession of tow drones.

   Each tow drone has short range, but it suffers minimal drag because it’s little more than a dense battery in the form of a flying wing. It then flies down to recharge after towing the client aircraft.

   The best fit for this isn’t solar, I think, but wind power. The tow line has a paravane, so it can dip into the water. This lets the tow plane act like a power kite. As it sweeps in circles, the props act as generators to recharge the batteries. The point is…you’re reusing the basic flight hardware for power generation.

   Alternatively, if solar power is good enough the tow planes might stay at high altitude to recharge. This isn’t so great for night flights, though…

   Reply
4. 

   June 29, 2018

   Isaac Kuo

   I wonder if in-flight towing could solve the problem even without major battery advances. The client aircraft has only a small battery…for the most part it’s a glider. It spends most of its time being towed by a succession of tow drones.

   Each tow drone has short range, but it suffers minimal drag because it’s little more than a dense battery in the form of a flying wing. It then flies down to recharge after towing the client aircraft.

   The best fit for this isn’t solar, I think, but wind power. The tow line has a paravane, so it can dip into the water. This lets the tow plane act like a power kite. As it sweeps in circles, the props act as generators to recharge the batteries. The point is…you’re reusing the basic flight hardware for power generation.

   Alternatively, if solar power is good enough the tow planes might stay at high altitude to recharge. This isn’t so great for night flights, though…

   Reply
5. 

   June 29, 2018

   andrew mcmillan

   Isaac Kuo some excellent ideas there.

   Reply
6. 

   June 29, 2018

   andrew mcmillan

   Isaac Kuo some excellent ideas there.

   Reply