Hi Charles, thank you for your very interesting question.
Storing the energy in lightning has been something scientists have debated over the years, even back to the days of Ben Franklin. In fact, several somewhat successful attempts have been made by ingenious inventors in the past, most of which involved giant capacitors and charging coils to limit the surge. This can and has been done on a variety of scales; Ben Franklin used a small Leyden Jar (a crude battery/capacitor) to successfully capture lightning energy, and others have used massive capacitors the size of a home for storage. Other than cost, there is no reason why massive capacitor/inductor systems could not be built to a scale capable of capturing a large percentage of the energy in a lightning strike.
One of the biggest complications for using lightning for our electrical needs, is in trying to regulate the energy. Lightning provides a massive amount of energy in a very short time frame (less than 1 second) and at varying amperages (18,000 amps to well over 100,000 amps) and at varying voltages. Building an electrical circuit capable of handling these highly varied and extremely powerful lightning surges has proven to be difficult, and then turning that energy into regulated stable 120-volt 60Hz electricity you use in your home, even more difficult.
The real problem with the storage of lightening, is that it is simply cheaper to make electricity the traditional way, than it is to build the infrastructure needed to safely capture and regulate lighting energy. This is why, to our knowledge, there are currently no real efforts being made at capturing lightning energy.
Now that said, scientists believe that there may be the very real possibility of one day tapping into the difference in potential between the earth and the ionosphere by creating ionized paths with laser beams. But this is apparently still very far off in the future. But who knows?
I hope this answered your question and thanks again for thinking of E&S Grounding Solutions.
The E&S Grounding Solutions Engineering Team
Photo credit: cr03