Johanna Flood
Servers are a bit picky. They need steady, clean electricity to work properly. All the time. That’s where a UPS comes in.
Before electricity reaches the servers, it typically passes through the UPS, which keeps things stable and filters out disturbances. UPS stands for Uninterruptible Power Supply. Three letters. Three main jobs.
You can think of a UPS as three things in one: a battery, a power “cleaner,” and a control system. A bit like a Kinder egg—but for engineers.
Around 70–90% of the total weight of a UPS system comes from the batteries.
It also acts as a safety net. If the main power suddenly fails, the UPS jumps in instantly and keeps everything running while backup generators start up a few seconds later. If everything works as it should, the servers don’t even notice.
So, UPS systems are great first aid for servers. But the environmental and social impact? Not always as great.
Let’s look at where the environmental and human rights risks show up in the UPS value chain.
There are two main types of batteries you will find i data center UPS. Both with different risk profiles.
Lead-acid batteries contain hazardous materials like lead and acid, which must be handled carefully. They are highly toxic and environmentally damaging if not managed properly. They have a short lifespan but are highly recyclable. Many older data centers still use them.
Lithium-ion batteries are the other type of batteries. Typically, they have higher efficiency than lead batteries and they need less space than lead-acid batteries. They have a longer life span than lead-acid batteries and they are usually less harmful to handle. However, there are known environmental and human rights risks in the supply chain from mining lithium. There are also risks if the lithium batteries catch fire, they burn extremely well and release toxic gases. Recycling is more complex and less developed than for lead-acid batteries.
UPS systems run 24/7, and they’re never 100% efficient. Even small losses add up over time.
The less efficient the system, the more energy is wasted—and the higher the emissions tied to that electricity use. So, efficiency really matters.
UPS systems are often oversized to be on the safe side. Oversized systems use more materials than necessary and often run less efficiently at partial load - this is when the servers are not running on full speed.
So, you and the environment end up paying twice: more resources upfront and more energy losses over time.
Apart from lithium, UPS systems require large amounts of materials like steel, copper, and aluminum—all of which carry significant environmental impact from mining and production.
On top of that, batteries and power electronics involve complex manufacturing processes, often using hazardous chemicals and posing risks to worker health and safety in the supply chain.
So, you and the environment end up paying twice: more resources upfront and more energy losses over time.
Bottom line
UPS systems are essential for keeping data centers running smoothly. But from a sustainability perspective, they’re far from invisible.
They solve one problem reliability while quietly contributing to others: resource use, energy losses, and supply chain risks.
There are many UPS providers on the market. Often, they don't produce all parts themselves. UPS providers rely heavily on their supply chain, and in a fast-growing industry like data centers, sustainability requirements can easily get lost. Here are 9 questions that can actually make a difference.