Lovins observes that power inputs in many industrial processes go into a bottleneck that makes power conservation hard if you start at the wrong end. The power goes into a long pipeline of process that emerges on the other end with some useful (in theory) work. If you start on the power input end, then reducing power x% requires percolating incremental improvements down the chain of linked machinery with each step reducing work at the step further down the pipeline. But if you start on the other end, changes automatically flow upward. The same, obviously, holds true for data centers. If you start by improving power efficiency of air-conditioning – a good thing in itself – you cannot obtain the scale improvements that can be gained on the other end of the pipeline by reducing the activities that use power and generate heat. That is, if you can increase work-done/computational-steps you drive savings up the pipeline. And the kind of large scale savings Lovins achieves in other industrial processes seem plausible: if you reduce power demand at the work end enough to reduce the inputs of cooling needed so that a smaller air conditioning unit can be used, you have a potentially greater savings than by improving the efficiency of the air conditioning unit.
The Amory Lovins bottleneck