Who Pays When the Data Center Never Comes? Contract Design and Stranded-Cost Risk in U.S. Large-Load Electricity Tariffs

Serving a hyperscale data center can require irreversible utility investment before the customer operates. If the project is delayed, downsized, or cancelled, who pays for unused capacity? This paper studies largeload electricity tariffs as public contracts against customer non-arrival and underutilization.

The evidence comprises 27 independent U.S. utility-state-docket policy chains, 167 source-level records, and 93 firstcoder-confirmed clause observations from operative documents. Clauses are coded as present, absent only after full-document audit, or not publicly verifiable; missing evidence is not converted into weak protection. A locked model-assisted blind recoding of 40 core-case cells yields 92.5% state agreement, 85.0% exact ordinal agreement, and quadratic-weighted Cohen's κ of 0.508; it is a reproducibility audit, not human inter-coder reliability.

The paper develops a five-architecture typology and a duration-sensitive backing measure comparing enforceable customer support with the remaining life of dedicated assets. A two-period model separates pre-investment deterrence from post-signing abandonment, and a two-state benchmark shows how competition for mobile projects can weaken backing below the national zeroexposure boundary. The cases reveal strong but heterogeneous safeguards.

An adversarial missing-as-zero exercise is underpowered and cannot establish rank independence, but shows why the current record cannot support a stable national cardinal ranking. Large-load tariffs determine whether speculativeinfrastructure downside remains with the large customer, moves to utility investors, or is socialized across ordinary ratepayers.