STUDY GUIDETechnology

Data centres and the power grid

Why the buildings that run online services need so much electricity, what that does to a local grid, and how grid operators decide who connects.

Updated 4 Nov, 22:15 · Linked to 1 live briefing · Select any text to ask about it

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1
Why data centres use so much power
A data centre is a building full of computers that run online services, storage and computing for other companies. The machines run day and night and must be kept cool, so a large site can draw as much power as a small town.
2
What a grid connection is
To draw power, a site needs a connection agreement with the grid operator, which promises a set amount of capacity. Operators can only offer what local substations and lines can carry at their busiest times.
3
Why queues form
When many projects apply in one place, requests can exceed the spare capacity. Building new substations and lines takes years, so applications wait in a queue while the operator decides what the network can handle.
4
The arguments
Supporters of new sites point to investment and jobs. Critics point to the share of power going to one type of user and to the effect on neighbours. Job estimates vary widely depending on whether construction work is counted.

2021
12% of demand
Data centres account for 12% of electricity demand in the Brennmark zone.
2023
Four applications
The Brennmark connection queue holds four data-centre applications.
2026
31% and 14 applications
Data centres reach 31% of zone demand; 14 applications totalling 2.3 gigawatts are waiting.
1 December 2026
Pause begins
An 18-month pause on new data-centre connection applications in Brennmark takes effect.
2028
New capacity due
The earliest date the energy minister gives for new capacity at Brennmark North.

: A building that houses computers providing online services and computing for other organisations.
: A contract giving a site the right to draw a set amount of power from the grid.
: The list of projects waiting for a grid operator's approval to connect.
: A site where electricity is transformed between voltages and distributed to local users.
: A unit of electrical power. A gigawatt is 1,000 megawatts.

Where

Fictional atlas drawn by Ford Colter for the demo.

Who uses Brennmark's electricity% of zone demand

Share of electricity demand by user type, year to September 2026, as published by the Tarsk Grid Authority.

institution
Tarsk's grid operator and regulator, which paused new data-centre connections in Brennmark.
group
Industry body representing data-centre operators.
institution
Lunevian think tank, part-funded by trade unions, that publishes research on jobs.
place
Tarsk's data-centre hub, served by the Brennmark North substation.

Why not just build more grid?

New substations and lines take years to plan and build. In Brennmark, officials say new capacity will not be ready before 2028.

Do data centres create many jobs?

They create many construction jobs for a few years and far fewer permanent ones. That is why estimates for the same projects can differ by thousands.

Does a pause affect sites already approved?

In Brennmark, no. Projects with signed connection agreements go ahead; only new and pending applications are on hold.