We’re starting to see a confluence between IT and energy that will change both industries. A windmill power data center is an interesting data point. At some time, we’re going to want to control the energy generation from the data center – for example, to run big batch jobs when the wind is blowing or to generate more power during peak billing periods or to shut down unnecessary heat producing computations during low energy periods. As smarter technologies become available for generating power from waste heat, and as carbon generation costs become integrated into prices for purchased power, the whole economics of running data centers will change and the data center will have to act like an intelligent factory – producing compute time against costs of heat production and power consumption. As we get there, we have to understand that one of the most important properties of the Internet comes from its “end-to-end” design.Â Earlier networks suffered from the problem of being designed as layers, but the internet protocols and hardware were designed to solve the problem of moving streams and packets around networks of machines – considering the problem in totality, not as a set of layered components.Â Modularity is not incompatible with end-to-end, but end-to-end requires an understanding of the applications and is incompatible with the component supplier view that dominates modern computer systems development.