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You can put the solar panel in space and beam concentraded light to the plane in laser form and get much higher watts per sq ft. No fuel weight should be an ad

You can put the solar panel in space and beam concentraded light to the plane in laser form and get much higher watts per sq ft. No fuel weight should be an advantage. Is there any disadvantage? Would transmission loss be too high? You’d still need batteries for takeoff/landing. But you could charge them at cruising altitude.

kaybe 9y ago
1) Prohibitively expensive. 2) Too many easily broken parts and too little fall-back mechanisms. (What do you do if it fails? You have to be able to reach the nearest airport, which, over the big oceans, will be near-impossible without carrying at least half-a-journey full of energy anyway.) (Good luck getting something like this through certification..) 3) NIMBYs will try to stop you from darkening their skies. If you want to take the energy from next to earth, there will be additional energy influx (and you can put a global-warming equivalent on that). There are many more if I think for more than 10s.
barry-cotter 9y ago
All energy transfer mechanisms double as weapons. Orbiting solar power stations are also known as death rays. This has military implications, to put it mildly.
DennisP 9y ago
Beaming to a plane would be difficult, but space solar power for the grid is actually starting to look feasible. I just read a book [1] about it. Lasers are an option but they're not very efficient, and blocked by clouds. Instead we can use microwaves. The watts per square foot would be just a little higher than sunlight, which is good for safety anyway. Total efficiency from satellite to grid would be about 50%, which isn't bad since it keeps running at full strength at night and on cloudy days, and sunlight is 30% stronger in space to start with. NASA's monolithic design from the 1970s would have been absurdly expensive even if launch were free. Some recent designs are completely different. The book focuses on SPS-Alpha, a modular design made of many thousands of identical components of eight different types, each only a meter or two wide, which self-assemble in orbit. There's no single point of failure, and the components are cheap since you mass-produce them. The book estimates a retail electricity price of $0.15/kWh. I plugged in the extremely low launch cost SpaceX is claiming for the BFR, and got a price of $0.045/kWh. That would decrease further over time. U.S. national average is about ten cents. [1] https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HNZ0Z96 https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HN...
- thinkcontext 9y ago
  How long does it take for the panel to produce the amount of energy it took to launch it into space?
  - DennisP 9y ago
    An ESA study in 2006 [1] estimated total energy payback including launch and manufacturing at a year or less, depending on various assumptions. It's similar to ground solar; launch energy is offset by the higher and constant solar flux in space. [1] Peter Ongaro, Leopold Summerer; "Peter Glaser Lecture, Space and a Sustainable 21st Century Energy System"; (57th International Austronautical Congress, 2006)

kaybe 9y ago

1) Prohibitively expensive. 2) Too many easily broken parts and too little fall-back mechanisms. (What do you do if it fails? You have to be able to reach the nearest airport, which, over the big oceans, will be near-impossible without carrying at least half-a-journey full of energy anyway.) (Good luck getting something like this through certification..) 3) NIMBYs will try to stop you from darkening their skies. If you want to take the energy from next to earth, there will be additional energy influx (and you can put a global-warming equivalent on that). There are many more if I think for more than 10s.

barry-cotter 9y ago

All energy transfer mechanisms double as weapons. Orbiting solar power stations are also known as death rays. This has military implications, to put it mildly.

DennisP 9y ago

Beaming to a plane would be difficult, but space solar power for the grid is actually starting to look feasible. I just read a book [1] about it. Lasers are an option but they're not very efficient, and blocked by clouds. Instead we can use microwaves. The watts per square foot would be just a little higher than sunlight, which is good for safety anyway. Total efficiency from satellite to grid would be about 50%, which isn't bad since it keeps running at full strength at night and on cloudy days, and sunlight is 30% stronger in space to start with. NASA's monolithic design from the 1970s would have been absurdly expensive even if launch were free. Some recent designs are completely different. The book focuses on SPS-Alpha, a modular design made of many thousands of identical components of eight different types, each only a meter or two wide, which self-assemble in orbit. There's no single point of failure, and the components are cheap since you mass-produce them. The book estimates a retail electricity price of $0.15/kWh. I plugged in the extremely low launch cost SpaceX is claiming for the BFR, and got a price of $0.045/kWh. That would decrease further over time. U.S. national average is about ten cents. [1] https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HNZ0Z96 https://www.amazon.com/Case-Space-Solar-Power-ebook/dp/B00HN...

thinkcontext 9y ago
How long does it take for the panel to produce the amount of energy it took to launch it into space?
- DennisP 9y ago
  An ESA study in 2006 [1] estimated total energy payback including launch and manufacturing at a year or less, depending on various assumptions. It's similar to ground solar; launch energy is offset by the higher and constant solar flux in space. [1] Peter Ongaro, Leopold Summerer; "Peter Glaser Lecture, Space and a Sustainable 21st Century Energy System"; (57th International Austronautical Congress, 2006)