The British coal age began in earnest about 1750, I think. That’s about 11 generations (of 25 years).
Trade in oil dates back to at least the same era in Yenangyaung in Burma https://allouryesterdays.info/2022/08/26/august-27-1859-the-oil-age-begins/
But crude oil extraction for European industry began in Romania in the 1850s. That’s about 7 generations ago.
https://www.rferl.org/a/romania-oil/31510946.html
(Although it’s fewer generations for me. My great great grandfather, and almost namesake John Schofield, was 31 in 1857. His son Benjamin would have been 9.)