No we're not. The data is clearly against this theory.
Coal was barely used until 1800s, early industrial revolution machinery used wood (indirectly solar power), charcoal, and river flow (indirectly solar power) instead. Oil didn't matter much until 1950s.
Amount of solar energy Earth receives annually is 3,850,000 EJ (and if we ever needed more there are ridiculously higher amounts of solar energy available is space). Human primary energy use is 487 EJ, or 0.01% of that. That's of course only because we conveniently don't count solar energy used to grow our food, and heat our planet - otherwise it would be fair to say human civilization uses 99.99% solar power (via photosynthesis, heating, water flow, wind etc.) and 0.01% all the other kinds of energy like fossil fuels, nuclear, geothermal etc.
We know fossil fuels were not necessary for industrial civilization because by the time we started using them we were already had industrial civilization. That's as good a proof as it gets.
History of ferrous metallurgy History of coal mining History of petroleum Solar energy
EDIT: Also, long before railways, river transport, and long distance sea transport were extremely common. If some place was inaccessible by water, canals were built. In fact rivers and canals, not railroads were the main mode of transport during the Industrial Revolution. Water transport requires ridiculously little energy compared to land transport, and requires no fossil fuels - even steam ships can use wood or charcoal. Oil wasn't even essential for transport - even as recently as during WW2 most armies relied on horses for carrying stuff around. Fossil fuels are completely irrelevant for explaining why industrial revolution happened. Transport during the Industrial revolution Horses in World War II
Wouldn't any energy stored on earth be "indirectly solar power?"
We have a sample of one modern human civilization, but there are some hints on how likely it was to happen.
Major types of hints are:
Data for:
Data against:
To me it looks like life, animals with nervous systems, Upper Paleolithic-style Homo, language, and behavioral modernity were all extremely unlikely events (notice how far ago they are - vaguely ~3.5bln, ~600mln, ~3mln, ~200k or ~600k, ~50k years ago) - except perhaps language and behavioral modernity might have been linked with each other, if language was relatively late (Homo sapiens only) and behavioral modernity more gradual (and its apparent suddenness is an artifact). Once we have behavioral modernity, modern civilization seems almost inevitable. Your interpretation might vary of course, but at least now you have a lot of data to argue for your position, in convenient format.