you know, if you want real good isolation from these transients, use an electric motor powering an AC generator - the efficiency is quite good (not perfect, but in the 95% range) and there is complete isolation of your house power from the external AC - particularly if you connect the two with a non-conductive coupler that is a few inches long, and you ground the two separately to separate ground rods, it would take a particularly pernicious lightning strike to jump to the house.
You could also build your house inside a giant faraday cage - but nobody would.
I repeat... If you are in a high-lightning area beef up the bonding and grounding, and add a good whole house surge arrestor. Especially if you have already been bitten once.
And get the local utility to beef up their surge arrestors on the power line feding the house. (Because they REALLY don't want you climbing the pole and messing with the 2400/4800/9600V feeder...)
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This does work quite well for HV isolation. I have worked on some
100KV ion implanters, that used this method (with a 1 meter lexan shaft) to provide power to the HV terminal equipment.That is a meaningless effort, there is effectively no such thing as an "isolated" ground rod, and it wouldn't do you any good if there were. The whole POINT of the ground rod is to tie everything to a common equipotential reference.
As well, the NEC (for an Installation in the US) would require you to bond the two rods together anyway.
"All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system"
and the rod would not (IMO) be considered "supplementary", which would exclude the allowance of Section 250.54
True, BUT, the galvanic isolation is not the only concern. I f the current takes a path through your "motor conductors" you can couple significant amounts of current to parallel conductors via transformer action, if those conductors run parallel to, and close to your house conductors.
Also I have been told that your phone lines are another frequent source of lightning current entry into your house, for locations where lightning is a big problem. {and then from your phone equipment/fax/computer (does anyone still use dialup???) to your power line.
jk
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