keithl wrote:title="With a space elevator, a backyard full of solar panels could launch about 500 horses per year, and a large power plant could launch 10 horses per minute."
... It's late, I'll need to check my references and do the calculations in the morning ...
IMHO, the space elevator concept is a placeholder, like GNU/Hurd was before Linus Torvalds invented a community development process around Linux that transformed free/libre software into a global phenomena, and Cygnus demonstrated high profitability for the GCC compiler suite. The space elevator concept will also be radically transformed by practical-minded heretics. The impractical orthodoxy will be sidelined and diehards will kvetch like RMS does.
The 2013
Space Elevators: An Assessment... can be purchased from
Amazon for $30. 349 page
pdf. A
paper and slides I presented to the space elevator conference in August 2014.
Details: Climbing to GEO requires 48 MJ/kg. Climbing to 100 km altitude (legal "space", not a practically useful orbit) requires "only" 930 KJ/kg, but also more than 200 tons of tether and anchor "orbiting" above for every ton supported statically at that altitude. This is a wasteful way to use an expensive and high maintenance asset, like a camping vacation on a major airport runway.
Assuming a 450 kilogram horse, 100% efficiency, and zero vehicle and life-support weight, 500 horses to LEO altitude is 210 GJ and to GEO altitude is 11 TJ, or 6.6 kW-years and 340 kW-years respectively. 10 horses or 4500 kg per minute is 70 MW to LEO altitude and 3.6 GW to GEO altitude. Real efficiencies will be abysmal, given the low long distance power transmission efficiencies and the extra power and mass needed to radiate waste heat into vacuum - precisely how abysmal causes heated

arguments, empirical data entirely lacking. Disposing of descent energy is even more problematic (the focus of my paper).
Why are we launching horses? Presumably they are dead, rotting, and infectious, and we are dropping them (descent displaced by coriolis acceleration) into the castles of our besieged enemies. This is FEBS, the Fractional Equine Bombardment System.