In this chapter, we use a scenario-based approach to present the real opportunities for carbon abatement arising from the use of cloud services, but also to identify the dangerous misconceptions that could undermine their energy and carbon saving potential. In particular, we emphasise the key and often forgotten fact that improving energy efficiency does not necessarily amount to curbing Green House Gases (GHG) emissions. Making a clear distinction between reduced energy consumption and a lighter carbon footprint is of particular importance in the context of cloud services because of their global nature and the huge differences in the carbon intensity of electricity generation between countries. We also present evidence that not all businesses or services are equal with respect to the carbon abatement potential of a cloud-based alternative, with “low-tech” small and medium enterprises often offering the best prospects.
TopIntroduction
There is widespread expectation that the Cloud has strong carbon abatement potential, simply because it bears the promise of a dramatic reduction in power consumption through (Baliga, Ayre, Hinton & Tucker, 2010) efficiency gains in resource utilisation and a substantial reduction of wasteful idling time, and (Cook, 2012) more streamlined management of Information and Communication Technology (ICT) assets.
However, it is all-too-often assumed that the environmental benefits of the technology are a given, which is not the case. In fact, this assumption rests entirely upon another, namely that the electricity used to power the Cloud’s data-centres and networks has a comparatively low carbon footprint. Yet in practice, this is not necessarily the case: siting cloud services hosting facilities in certain regions which depend heavily on fossil fuels for power generation can very severely reduce and, in extreme cases, even reverse any reduction in GHG (greenhouse gas) emissions from improved energy efficiency.
Another common misconception is that all types of businesses and services would benefit from the Cloud. Our analysis strongly suggests that, due to high network traffic and limited resource-sharing opportunities, some computationally-intensive applications are ill-suited for Cloud migration, at least from an energy saving and carbon abatement perspective.
On average, Small and Medium Enterprises (SME) tend to offer better GHG emissions reduction opportunities, due to underutilisation and inefficient management of proprietary ICT assets in small organisations. Similarly, favouring cloud-based provision of certain services to the general public may yield substantial environmental benefits, if it leads to reduced energy consumption on within the home.
In this chapter, we will show, by examining multiple scenarios, why maximising the use of renewable (or at least low carbon) energy sources to power data-centres and improving the Power Usage Effectiveness (PUE) of high-density ICT facilities jointly hold the key to realising the carbon abatement potential of the Cloud.