| Popis: |
Data centre metrics have historically used operational efficiency as a proxy for sustainability, because of the industry’s heavy reliance on power. More recently the industry has begun to recognise that its focus needs to go beyond energy consumption, with the creation of metrics for issues such as carbon, water and compute efficiency. However, single-issue metrics often consider only the operational phase, omitting impacts from other issues, during other stages in a facility’s lifetime. Further approaches exist to assess more holistically the impact of data centres, such as building environmental assessment methods, but none have the capacity to capture fully the interlinked nature of a system, where improvements in one area and to one impact, can adversely affect a totally different area and totally different impacts. The main aims of the research presented in this thesis are therefore to: benchmark the environmental impact of an existing data centre using life cycle assessment (LCA); compile a framework of components that should always be included to understand the effects of future technological advances on the whole system; determine areas within the facility that are currently sensitive to change; and establish a tool to expedite the application of LCA in the design and operation of data centres. The results of the LCA are found to present a cogent argument for the need to assess more holistically the environmental impact of data centres. Dominance of the operational phase to the overall impact, of which the IT provides the most significant contribution, and the severity of the impact on human health is concluded. Due to the use of free cooling, the embodied impact of the IT is found to be greater than the combined operational impact of the mechanical and electrical services. Although the total life cycle impact is dominated by the effects of electricity production, the second most significant impact derives from the disposal of waste products arising from the refining of metals that are used to manufacture IT components and electricity distribution networks. Finally, the release of carcinogens is found to be one of the largest contributors to the whole life cycle impact, and is almost equal in value between the embodied and operational phases. From the results it is concluded that three parameters are sensitive to changes in the design of a data centre and influence the overall impact: the level of energy consumed in operation for the IT equipment, cooling, and power delivery; the energy mix used to provide electricity; and the total IT equipment used in the facility’s lifetime. Finally, the model and framework are used to develop a novel tool for the fast application of LCA to data centres. Evolutionary for the industry, the tool provides decision support, coupling the environmental impact of the facility with the decisions made during their design and operation, and the means for mass benchmarking and a future LCA rating system. |
