Enabling Sustainable Clouds: The Case for Virtualizing the Energy System

Abstract

Cloud platforms' growing energy demand and carbon emissions are raising concern about their environmental sustainability. The current approach to enabling sustainable clouds focuses on improving energy-efficiency and purchasing carbon offsets. These approaches have limits: many cloud data centers already operate near peak efficiency, and carbon offsets cannot scale to near zero carbon where there is little carbon left to offset. Instead, enabling sustainable clouds will require applications to adapt to when and where unreliable low-carbon energy is available. Applications cannot do this today because their energy use and carbon emissions are not visible to them, as the energy system provides the rigid abstraction of a continuous, reliable energy supply. This vision paper instead advocates for a "carbon first" approach to cloud design that elevates carbon-efficiency to a first-class metric. To do so, we argue that cloud platforms should virtualize the energy system by exposing visibility into, and software-defined control of, it to applications, enabling them to define their own abstractions for managing energy and carbon emissions based on their own requirements.

Act

“…Recent efforts at the cloud-scale enable renewable energy-driven warehouse-scale data centers [6,16,24,66,97]. Furthermore, application developers design tools to characterize the carbon footprint of salient workloads.…”

“…First, we describe the overall carbon footprint model which accounts for both operational and embodied emissions. As operational emissions are better understood by the systems and computer architecture community [16,24,37,59,97], we focus on detailing the embodied emissions aspects of the model. Second, we describe the carbon-centric optimization targets to enable sustainable system and hardware design space exploration.…”