Layer 1 of the AI stack
Energy
The binding constraint on AI in 2026 is not chip allocation. It is megawatts, interconnection queues, and the physics of getting electrons to a rack. Every price further up this stack is downstream of the numbers on this page.
The situation, in five numbers
- US interconnection queue
- 2,600+ GW, waits approaching 5 years
- Projects that withdraw
- nearly 80%
- Demand growth
- 29 GW more needed by 2027, 67 GW by 2030 (Eric Schmidt); 126 GW additional demand through 2028 with a 49 GW US generation shortfall (Morgan Stanley)
- Data centre share of US electricity
- 6-12% of total US electricity by 2026, up from 4% in 2024
- Rack density
- average rack density up 69% year-over-year to ~27 kW; GB200 NVL72 draws 120-132 kW, GB300 135-200 kW
The consequence nobody states plainly: a queue position is not a power supply. With four in five projects withdrawing, announced gigawatts and delivered gigawatts are different numbers — and press releases quote the first. If your interconnection date is 2031, your 2026 chip decision is really a 2031 chip decision.
Where the power comes from
11 options, ordered by nothing — they are not ranked, because the right answer is entirely decided by when you need power and what you will accept. Lead time is the field to read first.
- Grid interconnection — 4-5 years typical, approaching 5 on average. Whatever the local grid mix is
- Nuclear PPA (existing plants) — 1-3 years to contract; the plant already exists. Effectively zero operational carbon
- Small modular reactors (SMR) — 2030s for meaningful capacity. Effectively zero operational carbon
- On-site natural gas turbines — 12-24 months, the fastest firm power available. High. This is the trade being made.
- Behind-the-meter generation — Depends on the generation, but it skips the queue. Whatever you build
- Solar + battery storage — 18-36 months. Near zero operational
- Wind PPA — 24-48 months. Near zero operational
- Fuel cells — 9-18 months, among the fastest on this list. Lower than turbines on natural gas; near zero on hydrogen, which is rarely available
- Enhanced geothermal — 3-5 years. Near zero operational
- Demand response and curtailable load — Months. Neutral to positive
- Converted bitcoin mine — 12-24 months to convert, against 4-5 years for a greenfield grid connection. Inherits the site's existing supply, which is frequently gas or stranded hydro
How the heat leaves
The crossover where liquid cooling beats air sits near 30 kW a rack on ten-year cost and 45–50 kW on thermals. Above that it stops being a choice: NVIDIA has confirmed liquid cooling is a mandatory architectural requirement for GB200 NVL72.
- Air cooling — Up to ~30 kW per rack, PUE 1.4-1.6 typical
- Rear-door heat exchangers — ~30-50 kW per rack, PUE 1.2-1.4
- Direct-to-chip liquid cooling — 50-200+ kW per rack, PUE 1.1-1.2
- Single-phase immersion — 100+ kW per rack equivalent, PUE 1.02-1.10
- Two-phase immersion — Highest available, PUE Approaching 1.02
- Free and evaporative cooling — Depends on the paired system, PUE Can push annualised PUE below 1.2 in the right climate
The numbers that decide
- PUE — power usage effectiveness — Total facility power divided by IT power. 1.0 is perfect; every 0.1 above it is overhead you pay for and never
- WUE — water usage effectiveness — Litres of water per kilowatt-hour of IT load. The number local communities and regulators increasingly care ab
- Tokens per watt — The metric that actually matters in 2026: useful model output per unit of power. It joins the chip layer to th
- Rack power density — Kilowatts drawn by one rack. The number that decides your cooling method, your floor loading and whether an ex
- The interconnection queue — The waiting list to connect new load or generation to the grid. In 2026 it is the single most important number
- Equipment lead times — transformers, switchgear, generators — How long it takes to buy the electrical gear standing between a signed power contract and an energised rack. M
Head to head
- Nuclear PPA (existing plants) vs On-site natural gas turbines — Clean and slow against fast and dirty. The defining 2026 trade, and most operators are quietly choosing gas.
- Small modular reactors (SMR) vs Grid interconnection — Two answers to the same question, both arriving in the 2030s.
- Direct-to-chip liquid cooling vs Single-phase immersion — The production method against the thermally superior one. Serviceability decides it, not physics.
- Air cooling vs Direct-to-chip liquid cooling — Where the crossover actually sits: about 30 kW a rack on cost, 45-50 kW on thermals.
- Solar + battery storage vs On-site natural gas turbines — Intermittent and clean against firm and fast. Almost always paired rather than chosen.
- Behind-the-meter generation vs Grid interconnection — Skip the queue and take the regulatory risk, or wait five years and take none.
- Fuel cells vs On-site natural gas turbines — The premium bridge against the default bridge.
- Enhanced geothermal vs Nuclear PPA (existing plants) — The two clean firm options. One is geology-limited, the other supply-limited.
- Two-phase immersion vs Single-phase immersion — Marginal thermal gain against a live PFAS regulatory question.
- Demand response and curtailable load vs Behind-the-meter generation — Two ways to get connected sooner: agree to use less, or avoid the wires entirely.
- Converted bitcoin mine vs Grid interconnection — Energised land you can buy this year against a queue position for the 2030s.
- Converted bitcoin mine vs On-site natural gas turbines — Two ways to skip the queue. One is a retrofit; the other is a turbine slot that may be 2031.
What it powers
Want this whole layer as one table?
The power and cooling options on these pages as a single CSV — lead time, capex, carbon, maturity, density supported, PUE, the catch and what each one decides — ready to sort, filter or load into a notebook.
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