Christian Belady has his posted on Changing Data Center Behavior Based on Chargeback Metrics. Here is the main point and results from the post.

Changing the Charging Model

In my presentation, I described how Microsoft now charges for data center services based on a function of kW used. If someone upgrades to a high-density blade server, they do not reduce their costs unless they also save power. This change created a significant shift in thinking among our customers, together with quite a bit of initial confusion, requiring us to answer the stock question “You’re charging for WHAT?” with “No, we’re charging for WATTS!”
Recording the Changes

From our perspective, our charging model is now more closely aligned with our costs. By getting our customers to consider the power that they use rather than space, then power efficiency becomes their guiding light. This new charging model has already resulted in the following changes:

Optimizing the data center design

Implement best practices to increase power efficiency.
Adopt newer, more power efficient technologies.
Optimize code for reduced load on hard disks and processors.
Engineer the data center to reduce power consumption.

Sizing equipment correctly

Drive to eliminate Stranded Compute by:

Increase utilization by using virtualization and power management technologies.
Selecting servers based on application throughput per watt.
Right sizing the number of processor cores and memory chips for the application needs.

Drive to eliminate stranded power and cooling—ensure that the total capacity of the data center is used. Another name for this is data center utilization and it means that you better be using all of your power capacity before you build your next data center. Otherwise, why did you have the extra power or cooling capacity in the first place...these are all costs you didn’t need.

I will be discussing the concepts of stranded compute, power, and cooling in greater detail in later posts.

Christian predicts electricity based chargebacks will change the behavior of the industry to think in terms of processing capability per kilowatt used.

Moving the Goalposts

I think it will take quite a bit of time for manufacturers to realize that the goalposts have moved. At present, it is quite difficult to get the answer to questions such as “What is the processing capacity of your servers per kilowatt of electricity used?” However, I do believe this change will come, which will drive rapid innovation along an entirely different vector, where system builders compete to create the most energy efficient designs. The benchmarking body, SPEC, has already started down this path with their SPECpower benchmark, but this needs to be done with applications.