VCF Green Insight: Measuring the Carbon Cost of Going Software-Defined

I’ve spent my whole career at the intersection of infrastructure engineering and software engineering for enterprise businesses. About five years ago, I got engaged with green IT through UN Global Compact working groups, helping businesses set strategy and goals and report on SDGs. Since then I started to focus on SDGs within the context of my own domain — IT infrastructure and software.

That’s when I became obsessed with one question: what does this actually cost the planet?

Not the money. The planet.

We talk about cloud as if it’s immaterial. We move workloads to “the cloud” and pretend the infrastructure has vanished. But it hasn’t. It’s just someone else’s data centre. Someone else’s electricity bill. Someone else’s responsibility — except, obviously, not. The carbon footprint doesn’t disappear. It just gets harder to see.

VMware Cloud Foundation was interesting to me because it’s explicitly positioned as “infrastructure modernisation.” The pitch is: move from traditional on-premise servers to software-defined infrastructure and you’ll be more efficient, more scalable, more cloud-like. All true. But what does “more efficient” actually mean in carbon terms?

I tried to answer that question. The result was VCF Green Insight.

The Carbon Visibility Gap

Most infrastructure teams don’t know their carbon footprint. They know their energy costs. They know their power consumption in kilowatts. But carbon? The actual greenhouse gas equivalent of their infrastructure?

That number is hard to get. Cloud providers publish some data, but it’s aggregate and often years old. Most on-premise infrastructure shops don’t measure it at all. You can request it from your facility provider, but you’ll get met with blank stares.

There’s a reason for that gap. Carbon accounting for infrastructure is genuinely complex. You need to account for the electricity consumed (the easy part). You need to account for the grid carbon intensity (which varies by region and by time of day). You need to amortise the embodied carbon of the hardware itself (the carbon burned during manufacturing) across its expected lifespan.

The SCI (Software Carbon Intensity) specification from the Green Software Foundation attempts to standardise this. It’s the first real framework for comparing carbon footprints of different infrastructure approaches consistently.

But knowing the framework and being able to actually measure it are different things.

Building the Measurement

VCF Green Insight is a FastAPI application that measures the carbon footprint of VMware Cloud Foundation deployments. You point it at a VCF cluster and it collects three types of data:

Energy consumption: CPU utilization, memory pressure, I/O load — the actual operational energy being used by the VMs and the hypervisor.

Grid carbon intensity: The real-time or regional average carbon intensity of the electricity grid supplying the data centre. This changes based on the generation mix — wind and solar have lower intensity than fossil fuels.

Embodied emissions: The manufacturing carbon of the physical servers, amortised across their expected 4-year lifespan and allocated proportionally to each workload running on them.

The formula is straightforward: ((Energy × Grid Intensity) + Amortised Embodied) / Functional Unit. The functional unit is usually a VM or a workload.

What’s not straightforward is actually collecting all that data and keeping it consistent.

The Interesting Parts

The most interesting thing I discovered was that operational carbon (the electricity consumed during runtime) is only part of the story. For typical server hardware, about 80% of the lifetime carbon footprint comes from manufacturing. The embodied carbon is baked in before the machine ever powers on.

Most infrastructure optimisation focuses on runtime efficiency. Reduce power consumption. Optimise CPU utilisation. Those are real. But they’re optimising 20% of the equation. The 80% — the manufacturing carbon — is invisible and forgotten.

VCF Green Insight accounts for both. It calculates the operational carbon of each workload. It also amortises the manufacturing carbon of the physical servers and allocates that to each VM based on its resource consumption.

The result is a number that actually represents the total carbon cost of an infrastructure decision.

What VCF Green Insight Actually Does

VCF Green Insight is a carbon impact modeling tool. You model an infrastructure transformation: Replace your Fibre Channel SAN with vSAN. Replace your physical routing with NSX routing. Replace your load balancers with NSX load balancing. Replace your intrusion detection appliances with NSX security.

You adjust three variables: service lifespan (3, 5, or 7 years), power usage effectiveness (1.4–1.8), and grid carbon intensity (the emissions intensity of the electricity supply). Then you get a dashboard showing baseline emissions versus post-transformation emissions — absolute carbon savings and percentage reductions, broken down by component.

The tool calculates both manufacturing carbon (Scope 3) and operational energy emissions (Scope 2). You see the total lifecycle carbon footprint of the current infrastructure compared to the software-defined alternative.

For infrastructure teams planning a transformation to VMware Cloud Foundation, VCF Green Insight answers: what is the actual carbon impact of this migration? How much do we reduce if we make this switch?

Why VMware Cloud Foundation

VCF is modular. That’s the point. You can run it with integrated vSAN (hyperconverged storage on your compute nodes) or separate it out and keep your Fibre Channel SAN. You can run NSX (software-defined networking) or keep physical networking and appliances. You can run NSX security or keep your physical intrusion detection systems.

Each choice has different implications — not just for performance or cost, but for carbon. A hyperconverged vSAN deployment might consolidate your infrastructure but add embodied carbon through new hardware. Keeping your existing FC SAN eliminates new server hardware but requires separate storage appliances.

VCF Green Insight lets you see that trade-off. What’s the carbon impact of going all-in on software-defined architecture? What’s the carbon impact of keeping your existing infrastructure components? The answer depends on your specific scenario — your power costs, your hardware lifespans, your grid’s carbon intensity, how much you consolidate.

The Broader Conversation

This is about making infrastructure decisions that account for real environmental cost, not just financial cost or performance metrics.

Most infrastructure teams optimise for uptime, performance, and cost. In roughly that order. Carbon rarely enters the conversation until compliance demands it.

The problem is that carbon, like security, isn’t a feature. It’s a property of every infrastructure decision. Every server you deploy has carbon. Every VM you run has carbon. Every region you choose has carbon implications. You can’t optimise it away. You can only make conscious decisions about it.

VCF Green Insight is an attempt to make those decisions conscious.

VCF Green Insight is available as a web app.