Why is the Renaissance considered the beginning of the modern age?

The "modern age" began with the Industrial Revolution which was characterized by the use of non-natural sources of power, first steam and then fossil fuels.

The Renaissance marked the end of the Dark Ages in Europe. The Dark Ages are called "dark" because there was little written during that period so the historical record is somewhat scant. The Renaissance brought increased interest in learning AND more access to learning. The feudal system was based on land ownership, but during the Renaissance, mercantile activity brought new wealth to people who were not aristocrats. These newly wealthy people wanted more political power, more opportunity for their children, more legal protection from aristocratic exploitation. And they valued education and they came to value art.