“Clean” and “green” are wide open to interpretation and misappropriation; that’s why they’re so often mentioned in quotation marks.
Not so for renewable energy, however. Somehow, people across the entire enviro-political spectrum seem to have reached a tacit, near-unanimous agreement about what renewable means: It’s an energy category that includes solar, wind, water, biomass, and geothermal power.
Renewable energy sounds so much more natural and believable than a perpetual-motion machine, but there’s one big problem: Unless you’re planning to live without electricity and motorized transportation, you need more than just wind, water, sunlight, and plants for energy. You need raw materials, real estate, and other things that will run out one day. You need stuff that has to be mined, drilled, transported, and bulldozed — not simply harvested or farmed. You need non-renewable resources
None of our current energy technologies are truly renewable, at least not in the way they are currently being deployed. We haven’t discovered any form of energy that is completely clean and recyclable, and the notion that such an energy source can ever be found is a mirage.
Source: The myth of renewable energy | Bulletin of the Atomic Scientists