green cloud

What is green cloud?

Green cloud is a buzzword that refers to the potential environmental benefits that IT services delivered over the internet can offer society. The term combines the words green -- meaning environmentally friendly -- and cloud, the traditional symbol for the internet and the shortened name for cloud computing.

There is some confusion around the meaning of the term green cloud (or green cloud computing). In some cases, industry sources use the term to describe the environmental benefits that result from the general movement to the cloud. For example, the cloud consolidates data centers and better supports a remote workforce, leading to improved resource utilization and the overall reduction of emissions.

However, it would be more accurate to describe these characteristics as the green -- or environmental --benefit of cloud computing, rather than green cloud. Even with these benefits, data center operators might make little effort to reduce their carbon footprint. That stance is likely to change, given the projected growth of cloud computing and increasing pressure to address the environmental impact of data centers.

According to a European Commission study on energy-efficient cloud computing technologies, EU data centers accounted for 2.7% of electricity demand in 2018, and this is expected to reach 3.21% by 2030 if electricity demand continues its current trajectory. Although the 2018 rate is higher than the global average -- estimated to range between 1% and 2% -- data centers are consuming a significant amount of energy and this usage will accelerate as more organizations move to the cloud and data center growth continues.

Today, cloud data centers are behemoth facilities, housing thousands of servers, racks of storage devices, miles of network and the peripheral infrastructure necessary to keep everything running. To address the environmental challenges associated with these facilities, service providers have been adopting green cloud practices to varying degrees, more so in areas under public scrutiny. In this sense, green cloud computing refers to the steps that service providers are taking to improve the environmental profiles of their data centers.

How does green cloud computing work?

Cloud service providers typically employ multiple strategies to attain greener data centers. These efforts target efficiency improvements in one or more of the following areas:

• Energy source. The provider uses renewable energy as much as possible to power its data centers. This often includes wind or solar energy, along with large battery banks for storing the collected energy. Some providers use renewable energy credits (RECs) to offset their carbon footprint, giving them license to claim that their data centers use 100% renewable energy. However, RECs are not the same as eliminating the use of fossil fuels.
• Facility. The provider takes measures to use energy more efficiently in its data centers. For example, a provider might locate a data center in a cold climate, underground or even on the ocean floor. The provider might also find ways to utilize the excess heat generated in the data centers, such as warming nearby buildings. Additionally, providers might use machine learning or other advanced technologies to monitor and optimize energy use. Modifying the data center floor layout to improve air circulation or implementing water cooling systems to handle equipment-generated heat are other strategies.
• Infrastructure. The provider optimizes the hardware and software infrastructure. For example, a provider might deploy hardware that consumes less energy or use strategies such as dynamic voltage and frequency scaling (DVFS) to reduce power consumption. The provider might also maximize resource utilization, such as implementing virtualization or software-defined infrastructure, to reduce the number of servers and storage devices.
• Workflow. The provider uses multiple strategies to optimize workflows at every level. This might include shifting workloads to different times, modifying applications to reduce network traffic, optimizing storage and server caches, automating routine tasks or taking any number of other steps to reduce energy usage.

As data continues to proliferate, storage systems play an increasingly important role in energy efficiency. To help address energy issues, the Storage Networking Industry Association (SNIA) introduced the Green Storage Initiative (GSI), which is "dedicated to advancing energy efficiency and conservation in all networked storage technologies and minimizing the environmental impact of data storage operations." As part of this effort, SNIA offers the Emerald Program, a collection of resources for measuring storage power usage and efficiency, as well as conserving energy in enterprise storage environments. 

Finally, because the color green is associated with paper money, the label green cloud has sometimes been used to describe the cost-efficiency of a cloud computing initiative, although this is relatively rare.

See also: green data center, green IT, green computing, green storage, sustainability risk management