What is universal
Compute needs power, networks, and heat removal.
Those relationships exist in every data center even when equipment, scale, ownership, power supply, and cooling architecture differ.
Data centers / Foundational guide
How does a data center work?
Short answer: A data center is a physical facility that brings computing equipment, electricity delivery, networking, heat removal, cooling, reliability systems, and operations together. Its local impact depends on the facility design and the public rules and infrastructure around it.
Evidence last reviewed 2026-08-23The physical chain
Electricity becomes compute, heat, and a local infrastructure question.
- 01
Grid + generation
Electricity is produced and moved through a regional system. A facility's consequence depends on the generation, transmission, and market or utility territory serving it.
- 02
Transmission + substation
High-voltage infrastructure and substations deliver large quantities of power at usable voltages. A project may require new interconnection and grid capacity.
- 03
Facility electrical system
Switchgear, transformers, uninterruptible power systems, and internal distribution move electricity toward racks while supporting reliability.
- 04
Compute + network
Servers combine processors, memory, storage, and fast networking. AI systems often use many GPUs operating in parallel.
- 05
Heat
Electrical work performed by processors ultimately becomes heat. The facility must move that heat away continuously.
- 06
Cooling
Air, liquid, evaporative, dry, and hybrid designs move heat through different pathways. The selected design changes electricity and water demand.
- 07
Water, where used
Water withdrawal, recirculation, discharge, and consumption are different quantities. Local source, season, and watershed conditions determine significance.
- 08
Backup power
Batteries and onsite generators can bridge interruptions. Combustion equipment can create local air-permitting and emissions questions.
- 09
Community interface
Land, roads, construction, taxes, utility cost allocation, water, noise, air permits, jobs, and enforceable commitments meet outside the facility boundary.
What is not universal
There is no single data-center water, jobs, or bill number.
Facility design, climate, project phase, utility territory, tariff, accounting method, and disclosure quality change the answer. Missing project information remains unknown.
Enter the model
Follow one mechanism at a time.
Evidence layer
Open the claims behind the system.
National estimates do not describe one local facility. Definitions, forecasts, geography, assumptions, and caveats remain attached.
Estimated
U.S. data centers used an estimated 176 TWh of electricity in 2023 — about 4.4% of total U.S. electricity consumption.
This is a modeled national estimate, not a meter reading from every facility.
Forecast
U.S. data-center electricity use could reach 325–580 TWh in 2028, or roughly 6.7%–12% of U.S. electricity consumption.
The width of the range is part of the finding: future AI hardware, deployment, and operating practices are uncertain.
Observed
Water withdrawal and water consumption are different measures.
Withdrawal is water removed from a source for use; consumption is the portion not immediately returned to the local water environment.
Estimated
A data center's water impact depends heavily on cooling design, electricity supply, climate, season, and the condition of the local watershed or aquifer.
The same annual volume can pose very different risks in different places and at different times of year.
Observed
Data-center backup engines and onsite combustion turbines can create regulated local air emissions and may require Clean Air Act permitting and analysis.
Electricity is not the only local environmental question; emergency and behind-the-meter generation matter too.