Branson has a track record of seriously underestimating the difficulty of the challenges he picks. Plus he seems to believe he can replicate serious engineering achievements - eg space flight - on a shoestring budget.
You're overestimating the capability of SpaceShipOne/Two. It goes to space for all of a couple minutes. It does not go to orbit. The engineering requirements aren't nearly as tough. We've been sending unmanned vehicles up there since the early 40's, and manned ones up since the late 50's, back when NASA was still called NACA.
The Apollo programme was 4% of GDP, by itself
The Apollo program cost ~$20B, over the better part of a decade, during a time when the US GDP was rose from around $600B to $1T. So, it used roughly 0.3% of the GDP over that time period.
There's even a type of energy storage system you can make with superconductors - one of the highest power density and efficiency energy storage methods known to man.
The ultimate capacity of one of these systems is on the par with supercapacitors, and an order of magnitude lower than traditional chemical batteries. Their high power, low capacity, and functionally unlimited cycle life make them useful as a transient power filter, rather than a meaningful energy storage mechanism. Their sudden and nearly instantaneous quench makes them downright frightening as a sizable energy storage mechanism.
This site is based in the US. Therefore, the convention it follows should be that of the US. Any use of a comma as a decimal delimiter here is simply wrong.
Besides that, the use of six digits when only two or maybe three are actually significant is just clumsy.
Like I use energy to lift a stone, and I get 100% of that energy back if the stone drops.
No body is fully elastic. You will have infinitesimally small energy losses due to changing internal stresses in the two bodies. You get very very close to 100% recovery, but not 100% recovery. The energy is still there. It hasn't escaped your hypothetical closed system. It is simply not recoverable in a useful form. It is disordered. Reversible processes are those "special cases".
Doesn't matter much, it's the same people that drive their cars that also buy supplies that require trucking.
So what? You're artificially buoying up industries that perhaps shouldn't be. Nearly all of our shipping is done over the road, due to cost and convenience. Make roadway shipping pay to repair its fair share of damage done to the roadway. Initially, shipping costs will rise. Costs for all products would rise across the board as those increased operating costs trickle down to consumers. Over time, those companies will find new ways to reduce costs. Money would be pumped into the rail system, expanding and modernizing it to improve speed and throughput. Manufacturing would become more regionally diverse so less has to be shipped across the country. Fewer vehicles on the road means lower traffic congestion. Less roadway maintenance further means lower traffic congestion. Locomotives are more efficient per unit of shipped material are more easily managed in terms of emissions. Fixed, limited access railways can be more easily converted to electric.
The trucking industry would suffer, unquestionably, but it's a much more complicated issue than you give it credit for, and perhaps the advantages in other areas outweigh those effects.
Semis burn 5x more fuel yet cause 80x more damage.
Is that taking into account traffic volume, as a typical loaded tractor trailer is going to cause several thousand times the damage as a typical sedan.
Electrolysis has nothing to do with thermodynamics
By that, you actually mean everything has to do with thermodynamics. You're adding energy to disassociate a molecule. Thermodynamics dictates that you cannot recover that same amount of energy by letting the constituent elements recombine. Tyr07's uncertain belief coincides with one of the fundamental principles at play in any real world system.
Fuel cell efficiency varies greatly, it goes up to 85% for current marketed high temperature hydrogen fuel cells.
No it doesn't. The only way you could hope to achieve anywhere near that is through some combined cycle process that scavenges waste heat from the fuel cell. You might find some experimental units pushing 70%, but anything commercially available is going to be under 60%.
Total cycle efficiency is going to be under 25%. That is complete nonsense, you must be bad in math.
Assuming realistic values for electrolysis and fuel cells, you're already well under 40%. Depending on your compression ratio, you're only likely to recover 50-60% of the energy spent compressing the hydrogen for storage, so that's either higher losses, or higher capital costs for storage volume. Tack on a couple percent for leakage, and 25% is very reasonable.