100% clean no, but 100% renewable is theoretically possible.

If the electric grid entirely eliminates fossil sources of energy, and the supply chain electrifies, and if the extraction equipment electrifies, and if the storage facilities are run off non-fossil fuel energy, and the manufacturing facilities, and everyone involved didn’t consume or use cattle products because of their methane emissions, and all buildings are wooden construction, and all polymers are plant-based, etc etc, then one could say a company uses 100% renewable energy.

But for practicality’s sake, 0% fossil fuel-generated electricity and heating is a good metric to call “100% renewable” for most things. If a manufacturing process inherently produces GHGs like portland cement concrete, you can adjust the definition appropriately.

And yes cap and trade strategies and whatever else are bs