Energy Density of the Vacuum

The energy density of the vacuum potential is enormous, even mind-boggling.  While scientists have estimated that energy by various means, a reasonable calculation is given by Wheeler and Misner in their Geometrodynamics.  In that calculation, Wheeler and Misner apply the formalism of general relativity to the zero point energy of vacuum.  The fabric of space appears as a turbulent virtual plasma consisting of particles whose size is on the order of Planck's length -- some 10 ^-33 cm. The energy density of the electric flux passing through each particle is enormous:  It is 10⁹³ grams per cubic centimeter, expressed in mass units (i.e., the energy per cubic centimeter has been divided by c²).

And that's just using the spatial energy density (the "decompressed" or ordinary energy).  The energy density of the vacuum is appreciably greater than what physicists normally calculate, because they do not calculate the additional time-energy density portion of the vacuum stress.  If we also allow for the time-energy (the "compressed" energy), we restore that c-squared division factor, producing on the order of 10¹¹⁰ grams per cubic centimeter, or -- in energy terms -- on the order of 10¹²⁷ joules per cubic centimeter.

J. A. Wheeler and C. Misner, Geometrodynamics, Academic Press, New York, 1962.