Yes, where does the data live?
As Mr A. Coward says, this works based on multiple premises.
* The data is replicated on both datacentres
* There is surplus capacity in the lower power datacentre
* No legal (data protection, sales tax) problems with moving the data
* When work is moved from the high power datacentre to the low power one, the disks of the high power datacentre can be spun down, the CPUs and RAM put into lower power states
Unless you have the capital to buy >1 data centre, and can afford the duplicate HDDs and networking overhead, just build all datacenters in places where electrons are cheaper and peak load coincides with the non-overtime period of your ops team.
