Are complicated software and instrumentation needed to measure and allocate energy costs and carbon to IT users? Or can we get by with simple, low cost methods for energy cost and carbon allocation? How precise do we need to be? This paper provides an overview of energy cost and carbon allocation strategies and their precision. We show that it is both easy and inexpensive for any data center, large or small, new or old, to get started allocating costs and carbon, but the expense and complexity escalate and ROI declines when excessive precision is specified.
