Cloud computing has arrived, big time. Forrester estimates that worldwide spending on public cloud computing services will grow from $25.5 billion in 2011 to $160 billion in 2020, a 22 percent annual growth rate. Businesses are increasingly substituting cloud-based for internal resources to capture benefits like faster scale-up/scale-down of capacity, pay-as-you-go pricing, and access to cloud-based applications and services without buying and managing on-premises infrastructure.
But we've heard little so far about the efficiency and green attributes of cloud computing. That is starting to change as we hear from cloud or as-a-service providers about the architecture and power sources behind their cloud infrastructure, and as we all start to analyze customer implementations of cloud resources vs. on-premises alternatives.
Cloud infrastructure addresses two critical elements of a green IT approach: energy efficiency and resource efficiency. Whether done in a private or public cloud configuration, as-a-service computing will be greener for (at least) the following three reasons.
1. Resource virtualization, enabling energy and resource efficiencies.
Virtualization is a foundational technology for deploying cloud-based infrastructure that allows a single physical server to run multiple operating system images concurrently. As an enabler of consolidation, server virtualization reduces the total physical server footprint, which has inherent green benefits.
From a resource-efficiency perspective, less equipment is needed to run workloads, which proactively reduces data center space and the eventual e-waste footprint. From an energy-efficiency perspective, with less physical equipment plugged in, a data center will consume less electricity.
It's worth noting that server virtualization is the most widely adopted green IT project implemented or planned, at 90 percent of IT organizations globally into 2011.
2. Automation software, maximizing consolidation and utilization to drive efficiencies.
The presence of virtualization alone doesn't maximize energy and resource efficiencies. To rapidly provision, move, and scale workloads, cloud-based infrastructure relies on automation software.
Combined with the right skills and operational and architectural standards, automation allows IT professionals to make the most of their cloud-based infrastructure investment by pushing the limits of traditional consolidation and utilization ratios.
The higher these ratios are, the less physical infrastructure is needed, which in turn maximizes the energy and resource efficiencies from server virtualization.
3. Pay-per-use and self-service, encouraging more efficient behavior and life-cycle management.
The pay-as-you-go nature of cloud-based infrastructure encourages users to only consume what they need and nothing more. Combined with self-service, life-cycle management will improve, since users can consume infrastructure resources only when they need it -- and "turn off" these resources with set expiration times.
In concert, the pay-per-use and self-service capabilities of cloud-based infrastructure drive energy and resource efficiencies simultaneously, since users only consume the computing resources they need when they need it.
4. Multitenancy, delivering efficiencies of scale to benefit many organizations or business units.
Multitenancy allows many different organizations (public cloud) or many different business units within the same organization (private cloud) to benefit from a common cloud-based infrastructure.
By combining demand patterns across many organizations and business units, the peaks and troughs of compute requirements flatten out. Combined with automation, the ratio between peak and average loads becomes smaller, which in turn reduces the need for extra infrastructure. The result: massive efficiencies and economies of scale in energy use and infrastructure resources.
So migrating workloads to cloud resources, or developing new workloads in a cloud-native environment, can help an IT organization contribute to energy-efficiency and sustainability goals. But so far, cloud services and their providers are doing little to help their customers on three other facets of a green IT program (see chart below).
Next page: How you should press your suppliers to find the greenest cloud solutions.