I wonder, would it be feasible for them to use wind power to run time insensitive batch jobs in the daytime - crank down the processing power on these jobs when there's less green energy around?
Google has insane optimization for power consumption at data centers, if there is something you can think of, they will have either done it or will be trying it.
For many a datacenter - balancing the loads across the three-phase power supply is one area that makes one of, if not the biggest difference in the bill/power charged for using. Though that for many a tech, is an area they are more inclined to overlook.
Then quality of the power (clean sine or noise spikes) auditing, then the factor that UPS's do square wave. Though that's more stability and indeed longevity of your kit plugged that appreciates those nuances.
It is one big rabbit hole and can imagine the likes of Google having dedicated teams to focus just on power optimisations as the dividends at that scale - more than pay for the team.
When you deploy a datacenter at this scale you contract for an amount of power and you're basically obligated to use it. The trick is to get more compute out of the same amount of power.
By the way if you still have AC UPS systems that is probably your #1 problem and you definitely will not benefit from some fancy machine learning thing. Just get rid of most of your AC systems. For example you may benefit by adopting Open Rack 48V-to-point-of-load scheme that uses an in-rack DC UPS.
Total, more the company inhouse data center type affairs - big, but not your cloud or google size affairs. Then doing one AC to DC conversion instead of all that overhead per system along with the associated heat and centralising - pays for itself.
The cut-off for that level of work I'd say is if you design your own servers over just speccing from a vendor level is when you would be doing this. Upto that, it's still vendor off shelf. Though been a while and an option some vendors may now offer at lower scales these days.
Do they openly share these advances & techniques? I know, it's a competitive advantage so I wouldn't fault them too much if they don't, I'm just curious.
I wonder if preemptible instances could be priced or available this way. They could choose to run idle or contract in case of expensive or dirty power.
(1) Existing power usage doesn't work that way. You're basically on the hook for a predicable amount of usage. Of course, this could change, but the inertia behind this paradigm is high.
(2) Google has a bunch of hardware with relatively fixed costs that they'd prefer to run 24 hrs/day, 365 days/year.
A big challenge for Google, and any large DC operators in general, is utilization. Ideally you want the entire fleet working at 100% all the time, so there's no real benefit to ramping up or down with energy supply.