How Many Supernovae Does the Local Bubble Energy Budget Require?

The Local Bubble holds thermal energy in its hot interior and kinetic energy in its expanding shell, and both reservoirs were supplied, on the standard picture, by supernovae in the Scorpius-Centaurus association. This study adds the two reservoirs from published size and pressure values and divides by the useful energy delivered per supernova. The interior thermal energy is 1.14e+51 erg and the shell kinetic energy is 2.91e+50 erg, so at a coupling efficiency of ten percent the budget requires about 11 supernovae, comfortably inside the fourteen to twenty explosions reconstructed from the association's stellar history. The agreement is a consistency result rather than a proof, because the efficiency is the least known factor, but it shows that no additional energy source is needed. All figures are computed from stated inputs with the deposited script, not measured anew.