Installments 1 and 2 mapped the cables. This installment is about what sits at their ends: buildings that consume electricity on the scale of countries and water on the scale of cities, held up by the same physics that made the cables matter.
The International Energy Agency estimated that data centers consumed around 415 terawatt hours (TWh) of electricity in 2024 — about 1.5% of global electricity consumption, growing at roughly 12% per year.[1] The IEA projects that amount could double to around 945 TWh by 2030, more than 15% growth per year.[1] To feel the scale in one number: in 2024 Google and Microsoft each consumed 24 TWh — more than many countries.[1]
National grids are discovering they are the constraint. Ireland is the specimen: data centres consumed 21% of metered electricity there in 2023, up from 18% in 2022 and from just 5% in 2015.[5] In eight years a small country's grid became, measurably, a data center's grid.
Singapore ran the same experiment in reverse: after a three-year ban on new data centers, it lifted the moratorium in April 2022.[1]
Electricity is half the footprint; water is the other. A 2021 study in the journal Npj Clean Water estimated that data centers consumed about 1.7 billion liters of water per day for cooling and remote power generation, with 57% drawn from potable supplies — and noted that fewer than one-third of operators measured their water use at all.[1]
The water constraint has already redrawn a project. Google first obtained permits in 2020 for its $200 million data center in Chile's capital, Santiago.[7] The Santiago environmental court then asked Google to respond to concerns that the data center could affect the city's main aquifer, and local courts temporarily revoked the project's authorization.[7] Months later, Google announced it would halt the plans and revise the project to comply with stricter environmental requirements — changing its water-intensive cooling system.[7]
Some of the internet's largest gravity wells were drawn north on purpose. On 27 October 2011, Facebook announced it would locate its first data center outside the United States in Luleå, Sweden, near the Arctic Circle.[6] The region markets itself as "the Node Pole" — it provides stable, low-cost electricity that is 100-percent derived from renewable sources, with cold air as a free cooling system.[6]
Between the cables and the buildings sit the switchyards: internet exchange points. DE-CIX Frankfurt is among the largest IXPs worldwide, with throughput of 19.6 terabits per second in July 2026, and DE-CIX operates exchanges in over 60 locations, with five further hubs exchanging peak traffic above 1 Tbit/s.[2] Amsterdam's AMS-IX, the older European hub, reported peak traffic of 12.019 Tb/s inbound and 12.075 Tb/s outbound.[3] A handful of rooms now carry a continent's data.
The counterweight to energy geography is physics. Latency in optical fiber is largely a function of the speed of light; the index of refraction of most fiber optic cables is about 1.5, meaning light travels about 1.5 times as fast in a vacuum as in the cable.[8] Divide 300,000 km/s by 1.5 and the internet's raw material moves at about 200,000 km/s — a server 5,000 km away is an absolute minimum of 25 milliseconds away before a single router or queue is counted.[8]
That floor is why compute can move to the Arctic but the experience of the web cannot: energy pulls the buildings, latency holds the users, and the two maps are not the same.
In the AI decade, the energy axis has outbid every other location factor. On 20 September 2024, Constellation Energy announced plans to reopen Three Mile Island Unit 1 in 2028, citing the resurgence in the need for nuclear-generated carbon-free electricity.[4] The entirety of the plant's energy output will be sold to Microsoft under a 20-year agreement to support the company's expanding network of data centers.[4] Unit 1 is an 819 MWe reactor — a hyperscaler's power contract is now big enough to resurrect the site of America's most famous nuclear accident.[4]
The internet now has two geographies. The first map is drawn by energy and water — where the buildings can stand. The second is drawn by the speed of light — where the users actually are. Cables are just the connections between them.
Ireland's 5% → 21% in eight years is the warning graph of the decade: a grid can become a data center's grid faster than any regulator expected, and the politics followed.
Chile shows the constraint turning veto. A technology backed by unlimited capital loses to an aquifer.
The nuclear restart is the tell. When a hyperscaler's power contract resurrects Three Mile Island, the physical internet's center of gravity has moved from the seabed to the grid.
[1] en.wikipedia.org/wiki/Data_center — Wikipedia: Data center (IEA estimates; Npj Clean Water 2021; Singapore moratorium; 24 TWh)
[2] en.wikipedia.org/wiki/DE-CIX — Wikipedia: DE-CIX (Frankfurt throughput 19.6 Tbit/s, July 2026)
[3] en.wikipedia.org/wiki/Amsterdam_Internet_Exchange — Wikipedia: Amsterdam Internet Exchange (AMS-IX peak traffic)
[4] en.wikipedia.org/wiki/Three_Mile_Island_Nuclear_Generating_Station — Wikipedia: Three Mile Island (2028 restart, Microsoft 20-year deal, 819 MWe)
[5] en.wikipedia.org/wiki/Energy_in_Ireland — Wikipedia: Energy in Ireland (CSO: data centres 21% of metered electricity 2023)
[6] en.wikipedia.org/wiki/Luleå — Wikipedia: Luleå (Facebook's first non-US data center; Node Pole)
[7] thehindu.com — Google says it will rethink its plans for a big data centre in Chile over water worries (AP, 18 Sep 2024)
[8] en.wikipedia.org/wiki/Latency_(engineering) — Wikipedia: Latency (engineering) (fiber index of refraction ~1.5)