What is the average range of voltage of lightning in sky? I wondered how much energy is required to produce , such a loud sound? What is the average range of voltage in sky? Is there any possible way to store it ,and use when needed?
 A: I'll answer your question in three parts.
"What is the average range of voltage in sky?"
I would hope that for sunny skies, it's near zero - otherwise it'd be nothing but bolts from the blue all day long. But I assume that you're talking about the average range of voltage in regular lightning. NOAA says that we have .1-1 billion volts in lightning.
"I wondered how much energy is required to produce , such a loud sound?"
Well, lightningsafety.com says that less than 1% of a bolt's energy is used towards making sound. A quick google search yields that a bolt has roughly 1 billion joules - so that's less than 10 million joules of energy towards that thunder.
"Is there any possible way to store it ,and use when needed?"
Not really. According to lightningsafety, roughly ninety percent of the energy in a bolt is dissipated in the air. What's left...well, we'd need really large capacitors to do so, and we'd have to take into account whether or not the lightning is positively/negatively charged, and oh, capacitors aren't that great for storing lightning. Totally not worth. Source: a quick google search.
Let's flip this question around. We see a great amount of energy arcing through the sky every time there's a thunderstorm. What are the chances that somebody like you, or a government official, or some genius scientist thought that this would be a great idea too? So far, the best they've come up with is centuries old - a lightning rod. The technology for harvesting lightning hasn't advanced during all this time. So how come all these genius scientists and other people haven't figured it out? How come Einstein didn't figure this out? Just by looking at this, it's possible to conclude, with a reasonable degree of certainty, that it's ridiculously impractical to harvest lightning, less so than breaking apart uranium atoms for energy via fission.
