Backed by Hoover Dam production, water and electricity. Assuming that he does not continue the deal Mr House made with NCR (95% output goes to NCR while Vegas got 5%). As we know Hub made bottlecaps are backed by water and still valuable during NCR economic downturn. Bonus point: Use the excess Hoover Dam electricity to power Sierra Madre Vending Machine he got in the abandoned bunker to make more gold bars. How feasible is this? Also from what i gather from the wikis, Sierra Madre Vending Machine is picotech in scale i think. The chips used are not some form of nanotech feedstock, but simple alloys of common and fissionable elements (which can be easily manufactured out of common junk and an energy source). One particular source is fission battery. I have no idea what the output of this little baby is, but to scale it to hoover dam watt production how big it's gonna be i wonder. Actually, you can convert Fission Battery into 25 energy cells. Which you can then convert 3 of them into 2 Microfusion Cells. Sadly, the MFC in the game is incorrectly have 1040.8 DC volts labelled as capacity, when it should be using watt-hours. Maybe anyone can help?