So Greenpeace laid out the stairway to a coal-free iCloud, stressing that Apple should not rely on Renewable Energy Credits, or RECs, purchased from clean energy producers far from its datafarms to green up its operations.
Among today's data-storage devices, magnetic tapes can degrade within a decade, while hard disks are expensive and need a constant supply of electricity to hold their information, creating huge need for power for the "data farms" behind cloud computing.
IBM's "brick" initiative which creates data storage farms out of cheap blocks of hard discs and the broader push for "blade" servers that make adding computer power easy to add were evidence of this move to commoditisation, said Mr Findlay.