# Grid connection & energy supply URL: https://justuju.org/concept/grid-connection/ Layer 1 · Physical & Energy A big AI data centre needs a large, steady supply of electricity, and getting connected to the grid can take years, so power, not chips, often decides where and when one gets built. ## D1 · Story A giant AI building needs as much electricity as a town. The wires, power stations and big transformers that bring it there take years to build. So companies often have to wait for power, or build where spare power already exists. 1. Ask for power: from the power company 2. Wait in line: others asked first 3. Build new wires: and power equipment 4. Power on: the computers can start Like: Building a new house is quick. Waiting for the water main to reach it is slow. ## D2 · Picture A data centre asks the local grid operator for a connection of a certain size. The operator studies whether the lines and substations can carry it, and often finds that new transmission lines, substations or transformers are needed first. Requests join a connection queue. New power stations queue too, so both the supply and the demand side can wait years. Grid parts such as large transformers have their own long lead times. That is why builders hunt for sites with spare grid capacity, add on-site generation, or agree to cut their load when the grid is stressed. A building can be finished, and chips delivered, long before the power is ready. 1. Request: ask for capacity 2. Queue: wait your turn 3. Studies: can the grid cope? 4. Upgrades: lines, transformers 5. Power on: racks can run Like: Building a new house is quick. Waiting for the water main to reach it is slow. Where it breaks: A water main serves one street. A grid is one shared, balanced system: a big new load can affect prices and reliability for everyone on it, which is why operators study each request so carefully. ## D5 · Frontier D2 treats a grid connection as a queue to wait in. At scale the queue itself is unreliable, demand forecasts disagree, and the rules on who pays are being rewritten. Speculative queues. Of the generation capacity that asked to connect in the US from 2000 to 2020, only 13% was operating by the end of 2025 and about 75% had withdrawn. Queue totals say little about what will actually be built (Berkeley Lab, 2026). Forecast spread. One national estimate puts US data centres at 6.7% to 12% of electricity use in 2028. A range that wide makes it hard to size new lines and power stations (Berkeley Lab, 2024). Who pays, and who can be curtailed. US regulators are asking whether large loads should pay the full cost of the grid upgrades they trigger, and whether loads that agree to cut power at peak times could be studied faster. The rulemaking is still open (FERC, docket RM26-4). ## Examples as of 2026-10-30 - PJM and ERCOT, US grid operators with long data-centre connection queues - EirGrid, Ireland's grid operator, whose 2026 rules ask new data centres to bring their own generation - Microsoft's deal to restart the Three Mile Island Unit 1 nuclear plant (now the Crane Clean Energy Center) - On-site gas turbines at large AI campuses ## Sources - IEA: Energy and AI, executive summary: https://www.iea.org/reports/energy-and-ai/executive-summary - IEA commentary: Overcoming energy constraints is key to delivering on Europe's data centre goals: https://www.iea.org/commentaries/overcoming-energy-constraints-is-key-to-delivering-on-europe-s-data-centre-goals - Berkeley Lab: Queued Up, 2026 Edition (US interconnection queues): https://emp.lbl.gov/publications/queued-2026-edition-characteristics - Berkeley Lab: 2024 United States Data Center Energy Usage Report: https://eta-publications.lbl.gov/publications/2024-lbnl-data-center-energy-usage-report - Berkeley Lab: 2024 United States Data Center Energy Usage Report (full report): https://escholarship.org/content/qt32d6m0d1/qt32d6m0d1.pdf - FERC: Interconnection of Large Loads to the Interstate Transmission System, Docket RM26-4: https://www.ferc.gov/rm26-4 - EirGrid: Data Centre Connection Offer Process and Policy, v3 (May 2026): https://cms.eirgrid.ie/sites/default/files/publications/Data-Centre-Connection-Offer-Process-and-Policy-V3-May-2026.pdf --- Justuju · https://justuju.org/ · Content CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Quote with a link to the page.