In general, migrating to the cloud saves energy and reduces carbon emissions compared to running workloads on-prem or in a private data center.
But that's not universally the case. Sometimes, your existing workload deployment strategy may be more sustainable than what you could achieve using the cloud.
Determining the difference – in other words, figuring out whether cloud migration will actually result in greater sustainability – boils down to assessing the sustainability of your current workloads and comparing that with the sustainability of the cloud.
Keep reading for tips on what to consider when making that comparison, and what to think about from a sustainability perspective before migrating to the cloud.
Assessing cloud vs. on-prem sustainability
The cloud tends to be more sustainable, thanks mostly to economies of scale. In the cloud, workloads run in very large, shared data centers, which can use energy and space more efficiently than smaller facilities.
That said, cloud data centers don't always operate more efficiently than on-prem or private data centers. To determine whether the cloud provider you're considering is actually more energy-efficient and environmentally friendly, evaluate the following.
Data center size
In most cases, the size of cloud data centers is larger than that of any private facilities that businesses might use to run workloads. But there are exceptions.
If your company has a particularly large infrastructure, for instance – say, many thousands of servers – and the infrastructure is consolidated in a single data center, your existing data center may be larger than the shared data center you'd migrate to in the cloud. In that event, the cloud may not be able to deliver better energy efficiency than you're currently getting.
And for smaller companies, running workloads inside a colocation facility, where multiple companies run their own servers inside a shared data center space, may be a way of achieving the same economies of energy efficiency that public cloud data centers provide. If you currently use collocation, then, don't assume that the cloud will necessarily be more energy-efficient.
Data center location
In addition to the size of your current hosting facilities and your prospective cloud data center, consider each facility's physical location.
Do you currently host your servers in a recycled, century-old building? If so, the total sustainability of your existing infrastructure might be better than that of a newly built cloud data center, when you factor in the energy costs associated with new construction.
Along similar lines, hosting facilities built in long-developed areas are more sustainable than those that require wild lands to be cleared. If your cloud provider built its latest data center in the middle of a forest, the environmental impact of workloads hosted in that data center will effectively be greater than the impact of workloads running in the middle of an urban area.
Another critical factor in workload sustainability is where the energy for data centers comes from. Cloud providers have made a lot of headlines in recent years through initiatives aimed at sourcing energy from clean sources like wind and solar. But not all of their energy comes from these sources. Remember, too, that if cloud providers claim to be "carbon neutral," they may achieve that status partly by purchasing carbon offsets, not by renewably sourcing all of their energy.
Most colocation providers and private data centers are subject to the same limitations, of course. But in some cases, it may turn out that the energy you're currently using to power your workloads is cleaner or greener than what a public cloud could deliver.
The point here is that it's important to assess where your workloads' energy currently comes from, as well as what cloud providers are doing to source clean energy. Although it's more likely on the whole that the clouds can provide cleaner energy, there are exceptions, especially for companies that have deliberately invested in clean energy for on-prem servers or private data centers.
The specifics of workload configuration pre- and post-cloud migration may also play a major role in determining how energy efficient your cloud migration will turn out to be.
If you plan simply to lift and shift on-prem workloads into the cloud, you will likely not end up with the greatest possible energy savings after your migration. Instead, your workloads might sit on under-utilized VMs, wasting energy in the cloud just as they wasted energy when they resided on-prem.
On the other hand, if you plan to take steps to optimize workload configuration for energy efficiency as part of your cloud migration – by, for example, migrating some of your workloads to more efficient cloud services, like serverless functions – you are in a stronger position to achieve actual energy savings through cloud migration.
The bottom line: It's true that migrating to the cloud generally yields lower total energy consumption than hosting workloads on-prem or in private data centers. But whether that's the case for your specific workloads depends on factors like where your hosting facilities are currently located, how you source their energy and how your workloads are configured.