Embodied energy or Emergy is an accounting methodology which aims to find the sum total of the energy necessary for an entire product life cycle. If we look at the ‘product’ data center we can say that it is basically a value stack. A supply chain of stack elements who act as a service component. People, Process and IT that adds up to an IT service component. (Check out the Data Center Pulse Stack at Data Center Pulse for more thoughts on treating the data center as a stack.) A data center has from an energy perspective a supply chain that consist of four large building blocks: the IT infrastructure (servers, storage and network) for processing workload, the primary power supply (UPS, PDU, etc.), the secondary support supply (cooling, generator, air handling) and the tertiary support supply (lighting, office space). To manage the energy usage of this data center stack effectively and efficiently, it needs not only to be treated as a system but also the life cycle must be taken into account. There is an initial investments of energy in the construction of the data center. The data center then produce energy for a number of years, to process an amount of workload, until it reaches the end of its effective lifetime. Along the way, additional energy costs are incurred in the operation and maintenance of the data center. And after the end of its effective lifetime there is an investments of energy in the disassembly of the data center. For the data center life cycle we thus can define three phases (see figure):
- pre-production; the construction of the data center facility (raw material extraction, transport, manufacture, assembly, installation)
- production; utilization of the data center facility (data processing and data storage as primary process and supplementary processes)
- post-production; the breaking up of the data center facility (disassembly, deconstruction and/or decomposition)
DC Energy Life Cycle
During production the primary power supply is directly delivering energy to the IT infrastructure, the rest of the power supply is supporting. A further process analysis of each phase in the data center life cycle can give more detailed information on the energy cost of a data center and can lead to an Energy Cost Accounting System
DC Cumulative Energy Life Cycle
