Data center developers canceled 25 projects in 2025, up from six the year before. That is the number that matters — not the aggregate gigawatt totals that AI companies announce, but the specific count of projects that will not get built.
The cancellations are the visible surface of a structural bottleneck. Medium-voltage switchgear — the circuit breakers and transformers that connect a data center to the grid — now runs 40 to 60 weeks on lead time, driven by a manufacturing base that cannot scale overnight regardless of how much capital is flooding in. At least 188 local opposition groups now operate across 40 states, up from a handful three years ago, organized specifically around data center development.
Developers announced 12 gigawatts of new data center power for 2026. Only about one-third of those projects have actually broken ground, according to KSST Radio. That leaves roughly four gigawatts under construction against twelve announced — and typical build times run twelve to eighteen months.
Sightline Climate tracks the broader picture: 710 data center projects in the pipeline through 2030, totaling 102.3 gigawatts of announced power demand; the grid has accepted about 40.8 gigawatts of it, or roughly 40 percent. 11 gigawatts of 2026 capacity remains announced with no construction signs, despite typical build times of twelve to eighteen months. Globally, only about 5 gigawatts is under construction for 2026, nearly triple what was built the previous year — but still a fraction of what was announced.
The scale of what is being proposed has changed faster than the infrastructure can absorb. A thousand megawatts is now the benchmark lease size for a new data center, up from 100 megawatts a few years ago. That is enough electricity to power roughly 750,000 homes. At that size, fewer sites qualify, interconnection queues grow longer, and more communities suddenly confront what a 1-gigawatt facility actually means for their local grid.
Stargate, Amazon, Meta, and Oracle are not sharing timelines. OpenAI paused its UK plan citing energy costs and regulatory friction. The same dynamics are active in the United States — quieter, because no one has announced a pause yet. They are just not breaking ground.
At least 10 states have proposed moratoriums on new data center development. A quarter of the 140 projects tracked by Utility Dive have not disclosed how they plan to be powered at all.
The 40.8 gigawatt figure is not a pessimistic read. It is Sightline Climate's derisking threshold: projects with signed interconnection agreements, power purchase agreements, or construction financing in place. It is a floor, not a ceiling. The AI buildout will happen. The physics just has a longer lead time than the press releases.