# Why Data Centers Are Booming

How data centres house racks of servers, why AI hardware draws so much power, and how that heat and electricity demand is driving a building boom\.

By PETE\!

Topic: Computing, AI & Electronics

[Open the interactive Jig](https://ask.jig.com/j/88wjAsZDVVXX)

## Transcript

### 1. The cloud is a building

Every search, video and AI answer runs on computers in buildings like this one: long, windowless halls with fans on the roof and a substation next door\. By the end you will see why so many are being built right now\. Drag the scene to look around\.

Data centres used about 485 terawatt\-hours of electricity in 2025, up from about 415 in 2024 \(IEA\)\.

### 2. Rows of racks

Lift the roof and the hall is full of identical black cabinets called racks, each about two metres tall and packed with servers\. The rows face each other in pairs, so cool air comes in on one side and warm air leaves on the other\.

Fronts face a cold aisle; backs face a hot aisle\.

### 3. AI changed the racks

A classic rack of web servers draws about 5 to 8 kilowatts, like a few kettles\. A rack of AI accelerators can draw 50 to 100 kilowatts or more\. Switch between them, or click the rack with the small plate on top\.

Power per server rack grew about elevenfold from 2020 to 2025 \(IEA\)\.

### 4. Power in, heat out

Nearly every watt a server uses ends up as heat\. Cooling units push cold air into the cold aisles, servers warm it, and the hot air rises back to the coolers\. Above about 20 to 30 kilowatts per rack, air is not enough, so AI racks pipe liquid to the chips\.

Blue dots are cool air, orange dots are air the servers have heated\.

### 5. Power is the bottleneck

Electricity arrives on high\-voltage lines, steps down in the substation's transformers and flows to the racks\. Generators stand by in case the grid fails\. Today the hardest part of building a data centre is often getting a big enough grid connection\.

Gold dots trace electricity from the grid to the server rows\.

### 6. The boom

AI training and answering questions need far more computing than simple searches, so companies are racing to build\. Press the button to grow this campus the way many are growing: new halls, more transformers and batteries\.

The largest cloud companies spent over 400 billion dollars on data centres in 2025 \(IEA\)\.

### 7. How big is the boom?

Worldwide, data centres could use about 950 terawatt\-hours by 2030, roughly double 2025\. That is still only about 3 percent of the world's electricity, but it is packed into a few places, which is why local grids feel it most\.

Bars: IEA estimates for 2024 and 2025, and its 2030 base\-case outlook\.