Richard, please: either Facebook shuts down at night and whenever the wind stops blowing, or it has not "met its 100% renewable energy goal".

I didn't think I would have to explain this, but here goes:

Electrical energy does not sit in transmission wires waiting to be used. Supply must be generated in real time, and must be precisely matched to demand. If supply of energy isn't within ~2% of demand, breakers trip and the grid goes down. It's never (intentionally) allowed to happen.

That means when insufficient solar and wind resources are available, all residences and  businesses (including Facebook) rely to some degree on plants burning natural gas for their supply of electricity. In the process they emit a lot of CO2, and there is no system of "credits", or "offsets", that can change that fact. Any attempt by Facebook, Apple, Google, or anyone else to sidestep it is 100% bull$hit.

If I sound exasperated it's because there's a lot of this on EC today, and because I think you know better.

While I agree with Bob's notion that calling Facebook's operations 100% renewable is disingenuous at best, I still commend them for their actions. Providing their massive market influence to fund these clean energy sources is far better than doing nothing, it's setting the pace for other tech companies to see they can do the same, and I believe it's just the beginning. 

Don't hang the 'Mission Accomplished' banner just yet, but use this as a positive sign of things to come!