You are talking about the energy of the blast. In my comment I was talking about the heat output. From the followup comments it seems I have not made it sufficiently clear.
replyThe energy of the detonation wave in rocket explosions is typically 1-2% of the energy in the fuel, at least that is the ballpark of what people use for estimating the effects of mishaps.
We also do not know if the tanks were fully filled -- it the past, rocket companies have called 10 second static fire tests a "full duration static fire test." We will probably find out later what it actually was meant to be.
I think we do know that the rocket was fully fueled. This was like a WDR with a static fire.
replyAbout the couple of times you have said "fully filled", is that a specific industry or engineering slang or term?
replyMaybe it was a bit too colloquial. I am not sure if this is very important. A formal term would have been "full propellant load." The phrase "fill level" is also used in NASA documents.
replyThe question was whether during this test the stage was loaded with the same amount of fuel as for an actual flight, or only a small fraction of that.