Editorial policy

Every figure carries a label

One of three, and it is machine-checked. Sourced means quoted verbatim from a named page, with an evidence snapshot recording the URL, the quote and the retrieval date. Derived means real arithmetic on sourced inputs, with the arithmetic printed on the methodology page. Assumed means we chose it, and it is disclosed at the point of use as well as in the register. 6 of the 98 registered figures are assumptions.

A page cannot print an unregistered number

Displayed figures are fetched through a registry lookup that throws at build time when the identifier has no entry. A writer cannot type a plausible dollar amount into a paragraph and ship it — the build stops. That is the mechanism that keeps the methodology page honest, because there is no second copy of the numbers for it to drift away from.

Assumptions never wear a source's clothes

Where a figure is ours, its registry entry points at our own methodology page rather than at a government or manufacturer URL. Attributing our own adjustment to somebody else’s document would be the precise defect the labelling system exists to prevent, and it is the easiest one to commit by accident.

A blank beats a fabrication

Where the published record stops, this site stops. There is no installed-cost constant anywhere in the data module because we could not obtain a citable one, so the calculator asks for your quote. The same rule governs export credit rates, outage frequency and incentives outside the single programme we could quote from a regulator. A fabricated anchor is worse than a missing one, because a missing number is visible and a fabricated one silently determines everything below it.

Figures expire

Every registered figure carries a review date six months after retrieval. Tariffs get refiled, tax provisions lapse, and datasheets get revised, so a number that was correct in August is not automatically correct in March. Stale figures block a new deployment rather than shipping quietly.

The calculators must be able to say no

A tool that can only produce a positive result is a marketing instrument. Every engine here has an explicit null path: a tariff whose spread cannot cover the round-trip loss, a price above the pack’s lifetime earning ceiling, a load the inverter cannot start. Those return sentences rather than large numbers, and the no-payback guide exists to explain them.

Advertising is separated from content

If advertising is approved it will be clearly distinguishable from editorial content and will never be presented as a recommendation. No advertiser, manufacturer or installer sees a page before it is published, and none has ever asked to. There are no affiliate links, no referral fees and no sponsored placements anywhere on this site; if that ever changes, it will be disclosed on the page it affects and not only here.

Corrections

A figure that no longer matches its source is a defect, not a matter of opinion. Report one through the contact page with the identifier from the register and it will be checked against the source, corrected, and its retrieval date reset. Engines are covered by golden vectors, so a reproducible wrong result becomes a test case rather than a quiet patch.

Who writes this

Andrew Flores is responsible for the site's research, calculations, source verification, and corrections. Every registered figure traces to a retrieved source, documented arithmetic, or a visibly labeled assumption; the evidence snapshots keep that basis available for review.