Hmm using some of that 20% recovery rate is going to be tight. But I look forward to it.
Energy of a vacuum is easy. If you open up a 1m3 cube of vacuum on the ground, you're effectively lifting the column of air above it up 1m. So the force required is 1m^2 * 1atm pressure. Energy = force * distance:
E = 1m^2 * 100,000 N/m^2 * 1m
= 100,000 N m
= 100,000 J
= 27.8 W-hrs
= 1668 W-minutes to generate 1m^3 of vacuum or
1.67 W-minutes to generate 1 liter of vacuum or
3000 W-minutes to generate 1800 liters of vacuum.
A thought I had was to use an atmoshpere made from a gas that's just slightly denser than HHO. That way the atmosphere can be thicker while having the same pressure at sea level. The HHO would still float all the way up, especially if there's only one gas in the atmosphere so it doesn't stratify into lighter gasses near the top.
Last edited by kallog; 04/25/10 06:14 AM.