Transformers - adjusting the voltage for the data center
Johanna Flood
Transformers come in many forms in and around a data center. But no, not those transformers.
Transformers in the data center context, are not the superheroes from the 90s. They look more like metal containers, like this. Their job is simple: adjust the voltage so the power can be used safely.
Transformers usually sit between the grid and everything else, quietly stepping voltage up or down. There is often a distribution transformer near or inside the building, converting medium voltage from the grid into low voltage for the data center
So, what are the environmental and social risks with transformers?
I spent many years in the energy transition field in ABB and Hitachi Energy, where transformers were essential building blocks. But they also come with risks: power losses, oil leaks throughout the lifecycle, high embodied carbon, environmental and social impacts from copper, potential biodiversity risks and deforestation linked to the transformer paper insulation, and safety risks during testing and maintenance.
Since transformers come in many shapes and designs, make sure you understand what you are buying. Is it a dry one without oil (but often with higher losses), or one which is oil-filled (and could be filled with esters instead)?
Before you buy a transformer, don’t just ask for the price – ask these 7 questions:
What is the total cost of ownership (TCO) – including energy losses and maintenance over the lifespan?
Is this a dry-type transformer, or does it use an insulating liquid? If liquid, is it mineral oil or a less hazardous alternative like esters? What are the pros and cons?
If it’s liquid-filled, is the system sealed to prevent leaks or contamination?
Is there a secondary containment system in place to capture leaks?
Does the transformer comply with applicable noise emission limits (indoors or outdoors)?
How is safety managed across the full lifecycle – from production to service, and decommissioning?
Does the product comply with Ecodesign requirements (Regulation (EU) 548/2014 and 2019/1783)?
If paper or wood-based materials are used, how is legal and sustainable sourcing ensured?
Even if you don't buy the perfect transformers this time, you as a data center sustainability manager will learn more about the equipment in your data centers.