FAQ · Data centers · Last reviewed November 10, 2026
Common questions about data centers
Short answers to the questions people ask most, each with its source and a link to the full facts on this site. Where the evidence is contested, the answer shows what supporters and skeptics each point to.
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The basics
What is a data center?
A building full of computers, called servers, that run around the clock. They store information, do the computing behind apps and websites, and send the results back over the Internet. The Department of Energy’s Lawrence Berkeley National Laboratory defines one as “a facility used to house computer systems and associated components.”
Government LBNL 2025 Update, glossary
Are data centers all about AI?
No, but AI is the fastest-growing part. AI servers used roughly 23% of U.S. data center electricity in 2023 (our calculation from the report’s figures). Most of the rest went to everyday computing such as email, streaming, banking and storage. Berkeley Lab’s reference case projects that AI servers will use 55% by 2030.
Government LBNL 2024 report, pp. 7, 49–50 · Government LBNL 2025 Update
Does a data center store my personal data?
Often, yes. Cloud email, photo backups, online banking and social media keep their information on servers in data centers, sometimes in another state or country, as Google’s and Microsoft’s privacy policies say. Many data centers hold no consumer data at all, and the company that owns the building is often not the one that owns the data inside it.
Industry Google Privacy Policy · Industry Microsoft Privacy Statement
How many data centers are in the U.S.?
No government agency publishes an official count. Berkeley Lab’s 2024 study mapped “over 3,000 data centers,” and commercial databases list more. Our Tracker shows the ones found in public, openly licensed data.
Government LBNL 2024 report, sec. 4
How big is a large data center?
Data centers are measured by how much power they can draw, in megawatts (MW). The International Energy Agency says a conventional data center may be around 10–25 MW, while a hyperscale, AI-focused one can be 100 MW or more. One megawatt running all year is about what 810 average U.S. homes buy in a year (our calculation from EIA figures), though data centers rarely run at full capacity.
Government International Energy Agency, Energy and AI, 2025 · Government U.S. Energy Information Administration
Electricity and the grid
How much electricity do data centers use?
About 4.4% of all U.S. electricity in 2023, and an estimated 192 terawatt-hours, or 4.7%, in 2024. Berkeley Lab projects 9.5% to 15.3% by 2030.
Government LBNL 2024 report · Government LBNL 2025 Update
Will data centers raise my electric bill?
The evidence is contested. Supporters point to a Berkeley Lab and Brattle study finding that from 2019 to 2024, states with the fastest demand growth saw inflation-adjusted prices fall by more than 1¢ per kilowatt-hour. Skeptics point to a Carnegie Mellon and NC State study projecting an 8% rise in average U.S. generation costs by 2030, and over 25% in central and northern Virginia. Much depends on how utilities divide the cost of new power plants and lines.
Government Berkeley Lab & Brattle, Oct 2025 · Academic Carnegie Mellon & NC State, Jul 2025
Who pays for new power lines and substations?
Small data centers use the same local lines as other businesses; large ones need their own connection. Dominion Energy says loads of more than 50 megawatts typically require new transmission lines and a new substation, taking one to two years. Whether the data center or other customers pay is set by utility commissions and lawmakers, often through special rates for large customers called large-load tariffs.
Industry Dominion Energy, Data Center Requests
How a data center connects to the grid →Legislation & policy →
Water, noise, air and land
How much water do data centers use?
It depends mostly on how a site is cooled: evaporative systems consume water continuously, while closed-loop systems recirculate it. U.S. data centers consumed about 17 billion gallons directly in 2023, and about 211 billion gallons were used at the power plants making their electricity. Single sites range widely, from Google’s Council Bluffs, Iowa, data center at about 2.8 million gallons a day in 2024 to Microsoft’s mostly closed-loop Mount Pleasant, Wisconsin, campus, projected at up to 8.4 million gallons a year.
Government LBNL 2024 report · Industry Google 2025 Environmental Report · Government City of Racine records, via WPR
Are data centers noisy?
Cooling equipment, fans and backup generators make noise. Virginia’s legislative auditors estimated 40–59 decibels at homes near sites that drew complaints, between library-quiet and normal conversation, and found at least 15 Virginia data centers, about 10%, with a hum residents find problematic. Standard decibel limits capture low-frequency hum poorly.
Government Virginia JLARC, Dec 2024, pp. 76–78, 86
Do data centers pollute the air?
The main source is diesel backup generators, used during outages and for testing. A 2026 Virginia Commonwealth University study of Northern Virginia found generators run about 5% of the time and emit about 4–7% of what their permits allow, about 11% of the region’s nitrogen oxides from large sources. If run at full permitted levels, they would produce about 74%.
How much land does a data center take?
New campuses are much larger than a few years ago: a typical target of 200 or more acres and about 150 megawatts, up from about 15 acres and 40 megawatts. Some landowners have been offered $40,000–$50,000 an acre; some farmers have turned down offers to keep land in farming. There is no national count of farmland converted to data centers.
News Mission Critical magazine, 2022 · News Farm Policy News (Univ. of Illinois), Mar 2026
Jobs and taxes
How many jobs does a data center create?
Most jobs are in construction. Virginia’s legislative auditors found the industry supports about 74,000 Virginia jobs, including indirect jobs, about 80% of them tied to construction. About 4,400 people work directly at Virginia data centers.
Government Virginia JLARC, Dec 2024
Do data centers pay their way in taxes?
Locally, they can pay a great deal where they cluster: Loudoun County, Virginia, collected $1.2 billion in data center property taxes in fiscal 2026, 39% of its budget. At the state level, Virginia’s sales tax exemption for data centers totaled $2.7 billion, 53% of all state economic development incentive spending from fiscal 2015 to 2024. Whether such incentives decide where data centers locate is debated.
Government Loudoun County · Government Virginia JLARC, Nov 2025
In your community
Is there a data center near me, or one planned?
Our Tracker maps U.S. data centers and proposed projects, with owner, status, power and any tax incentives, and every row links to its sources. The “near me” button finds sites around you; your location stays on your device. The list comes from public data and is not complete.
What laws and rules apply to data centers?
Rules come from many levels: federal and state bills, governors’ executive orders, utility commission decisions on rates, and local zoning, moratoriums and ballot measures. Our Legislation page shows each one’s current status and links to the official record.
How can I have a say on a proposed data center?
Public hearings are where residents can comment on the record. Our Calendar lists upcoming hearings, regulatory deadlines and events, each with an official notice or organizer page; confirm details with the organizer before you go.
Where can I read the original reports?
Our Library collects reports, public records and company filings from every perspective, each linked to the original. Public records also have a dated backup copy.