Re: 300 lightning strikes
I was wondering about the 300 lighting strike equivalent but a quick bit of searching revealed that an average -ve lightning stroke delivers ~500MJ of energy (+ve bolts are more intense but less common ~5%). TNT (as a rough yardstick) yields a little over 4MJ / kg, so it would seem that ~125kg of TNT (a fairly small bomb) ~= 1 average bolt of lighting.
If we use Pete 2's lowest number for the total weight of bombs dropped, 1 Mt, and multiply it by 2000 (for US tons, to get a lower bound) we get get 2 Glb. Divide this by 2.2 to get 9.09e8 kg.
Tot energy = 9.09e8 * 4e6 = 3.6e^14 J
Divide this by 5e8 to give equivalent number of lightning bolts = 7.2e4 = 720,000.
If we go with 6 bolts per minute then we have 720,000 / 6 = 120,000 minutes = 2,000 hours = 83.3 days.
But note that if that figure of 6 bolts per min is for the whole of Europe then we really need the average rate just for Germany, which must be considerably lower.
Corrections welcome for any errors in the maths.
Of course, another way of looking at it is to remember that bombs did far more damage during the war than lightning ever did.