Technical Trust

A finding is only as useful as its basis.

Documented software tests and bounded public-data exercises support the methods described here. The public-data exercises checked mapping, data quality and selected accounting and arithmetic; they did not establish actual site spare capacity. Customer-site validation and qualified external engineering review remain outstanding.

Supported methods and their boundaries

Headroom is read-only evidence software for an analyst-assisted assessment. An analyst maps supported exports; the responsible engineer confirms the equipment arrangement, conditions and assumptions. Headroom does not automatically interpret arbitrary documents or integrate with live equipment.

Natural gas: one grid connection and one already-running unit

One natural-gas engine or turbine on a common AC bus, evaluated with supplied baseline and proposal profiles. Applicable manufacturer operating points and conditions must be documented. The method does not interpolate, extrapolate or automatically derate an unprovided operating point.

Gas evidence separates pipeline delivery rate in MMBtu/hour from a finite allocation in MMBtu, both on a lower-heating-value basis. Pressure, fuel quality, protections and permitted operating periods also matter. This is not a diesel-tank model or a forecast of available runtime.

No gas-plus-battery combination, multiple units, export, startup, islanding, automatic dispatch, optimization, gas-network hydraulics or replenishment scheduling. A whole-window allocation failure does not invent a crossing time.

Grid, battery and diesel: one site, one battery, one running generator

One grid-connected site, one battery and one already-running No. 2-D petroleum diesel generator, with one isolated closed-return fuel tank. The method checks supplied baseline and request profiles, applicable limits, finite-window energy and fuel, reserves and baseline protection.

Generator net output and external auxiliaries are constant within each modeled trajectory. Site-load and battery-profile changes use explicit aligned intervals. Applicable limits and fuel-consumption evidence must be supplied.

No export, startup, islanding, refueling, multiple batteries or generators, automatic dispatch, optimization or source-specific charging attribution. A supported finite window is not repeat-cycle capability, firm capacity or permission to operate.

Cooling: bounded air, single-phase liquid or mixed arrangements

A compatible power/resource evaluation can be accompanied by one IT heat boundary, one air-removal branch, zero or one single-phase liquid branch with ordered serial interfaces, and one documented common final heat-rejection stage. Mixed cooling accounts for both paths; liquid-cooled IT may still have residual air load.

Each stage requires evidenced capacity at the applicable conditions. Baseline and proposal use the same physical chain but may have different demands, capture fractions, conditions and applicable capacities. Parallel equipment is represented only through an independently reviewed net aggregate, not automatic addition of equipment ratings.

Cooling electricity, heat removal and applicable capacity are separate quantities. Native site-load profiles must reconcile cooling electricity without double counting. Generator and battery heat must be confirmed outside the assessed cooling and rejection boundaries; missing confirmation leaves the affected checks unresolved, while a known failure still produces Not supported. Without an established failure, unresolved required evidence leaves the overall finding Unknown. Observed heat transfer is not a capacity rating. Shared sink allocations, uncertainty, physical limits and protected service remain explicit.

Transport, flow, fluid and temperature compatibility require supporting evidence. Latent and condensation requirements need separate confirmation. Chilled-water air handling without IT liquid capture remains air-cooled IT; it is not evidence of liquid-cooled IT.

No generic immersion or two-phase support, arbitrary rear-door or loop-network model, hydraulic or computational-fluid-dynamics simulation, rack/chip-temperature guarantee, automatic plant optimization or unrestricted campus aggregation.

Records and conditional evidence checklist

Three evidence levels. Different conclusions.

Software verification

Tests using simulated site data check the documented software behavior, including bounded air, liquid and mixed cooling, known failures and unresolved evidence.

Public measured-data checks

Separate electrical and thermal exercises check mapping and reported quantities. Neither establishes actual ESIF spare capacity or a complete electrical-and-thermal capacity conclusion.

Customer and engineering validation

An authorized real-site package, qualified external engineer review and evidence of operator usefulness remain outstanding. Software acceptance does not close those milestones.

Recorded software verification, integrity and replay results

The final benchmark used the unchanged, previously verified product implementation; its records closeout did not change the software.

Different, overlapping sets. No cumulative test total.
SetRecorded resultWhat it establishes
Product acceptance1,991 tests passedPreviously recorded full successor acceptance, reused for unchanged product source. Not a fresh full-suite run for the final benchmark.
Affected source tests129 tests passedFresh benchmark and affected-regression checks in the source environment.
Extracted environment129 tests passedThe overlapping affected tests in the extracted environment, not another independent acceptance suite.
Output reproduction8 files byte-identicalRecorded observed-result files regenerated exactly; not proof of physical measurement accuracy.
Selected bundle replay13 replays passedSelected reproducibility checks, not 13 real-site validations.
New archive integrity358 hashes matchedFile integrity against the recorded manifest, not permission to redistribute restricted materials.

These counts overlap and are not additive. Matching files and repeatable results do not establish measurement accuracy, engineering approval or customer validation. The 1,991-test acceptance applies to the unchanged product implementation; the later benchmark checks are separately identified above.

What the public-data exercises establish

Electrical records

A bounded exercise using Energy Systems Integration Facility (ESIF) electrical records checks mapping, consumption and power usage effectiveness (PUE) accounting, data quality and replay. It does not establish installed-site spare capacity.

Published electrical-data reference (NLR)

Thermal records

A separate exercise covers positional mapping, temperature differences and reported-heat arithmetic across 1,225 observations from an incomplete September 1, 2016 sample. Missing periods were not imputed or replaced.

It does not independently establish flow, fluid properties, instrument accuracy, capacity ratings, sink allocations or a matching electrical model. The two exercises are not a combined site-capacity validation.

The capacity examples use separate synthetic systems, not actual ESIF equipment, limits or operating assumptions. No endorsement, certification, development participation or customer relationship involving the U.S. Department of Energy or the National Laboratory of the Rockies is implied. Thermal-data reuse questions remain unresolved. The public findings do not include the underlying thermal dataset.

How to read a result

Supported
The required checks support the supplied finite scenario within its documented conditions, without granting operating authorization.
Not supported
A known constraint prevents support, even when other checks pass or evidence is missing.
Unknown
Required evidence prevents a conclusion, and no established failure determines the finding.
Not evaluated
The assessment was not performed for this question or domain.

Unknown does not mean zero physical capacity.

Power/resource, thermal and overall conclusions are reported separately. Diligence priorities and intake readiness are separate from capacity findings.

October 4, 2026: generator and fuel verification record

Verification record: October 4, 2026

Software checks, not site validation.

The October 4 records cover the standalone generator/fuel model and its extracted review package. They are retained as an earlier verification record, separate from the October 11 combined Stage 4 checks below.

This earlier entry describes the scope of that work rather than listing test counts. It is not a fresh verification of the combined engine.

The generator demonstration covers one already-running, grid-connected diesel generator, isolated No. 2-D fuel inventory, and supplied constant baseline and request profiles. It excludes startup, refueling, optimization, battery combinations, and equipment control.

Examine the decision, not just the result label.

The reviewed synthetic examples separate original records, changed-record reassessments and declared alternatives. Each identifies the relevant boundary, period, driving margin and next records. Electrical support is not a thermal finding, and a known failure is not erased by missing evidence elsewhere.

The commercial demonstrations use assumed full-interval demand bounds; they are not measured customer performance or evidence of production deployment. Their review does not replace customer-site validation or responsible-engineer confirmation.

Operator decision and changed records · Portfolio constraints and evidence gaps · Separate coupled finding

October 11, 2026 test counts, provenance and replay checks

Verification record: October 11, 2026

Combined Stage 4 software verification

The retained final-revision logs report the checks below. These are originating-run internal software checks on simulated cases, not external engineering approval or real-site validation. These dated checks describe that retained implementation, not a new acceptance run.

SuiteRecorded resultScope
Stage 4-only68 tests passedCombined-result aggregation, required-check coverage and result semantics.
Combined targeted suites756 tests passedTargeted checks across the combined stages, including Stage 4.
Full explicit-successor suite1,447 tests passedThe complete repository successor run; no failures, errors, skips, deselections or expected-failure exemptions.
Historical regressions28 tests passedPreserved regression checks against the corrected successor behavior.
Extracted compact package694 tests passedTests run from the extracted review package in a fresh, pinned environment; not the full repository suite.

These sets overlap and are not additive. Do not sum them into a total or treat them as independent approvals.

Package checks also verified 482 artifact hashes and exact membership, seven stage replay commands, and eight tamper-rejection probes. Fresh generation reproduced 68 Stage 4 artifact byte strings: 32 JSON reports, 32 Markdown reports and four supporting files. These are artifact checks, not additional test-suite counts.

The result applies to the modeled inputs and finite window. Software reproducibility and matching hashes do not establish the accuracy of equipment records, customer validation or permission to operate a site.

One site. One question. An agreed period.

First Site Evaluation

Start with a fit discussion by email. The paid assessment covers one site and one decision, with scope, quote, authorization and data handling agreed before records are shared.

Standard assessments: Written finding within five business days after scope is agreed and the required records are confirmed. Broader assessments, including coupled power-and-cooling work, follow the schedule agreed in the written quote.

Request a First Site Evaluation

Review the records checklist and who develops Headroom. No sensitive records are needed for the initial inquiry.

Read-only, export-based and analyst-assisted. Findings apply to a supplied proposal, defined period and supported method; they are not operating approval or guaranteed capacity. Public capacity examples are synthetic. Customer-site validation and qualified external engineering review remain outstanding. Method boundaries and verification