Methodology

Our calculations are versioned, reviewed, and reproducible. Each result carries a formula version so a future calculation can be reproduced against the same method.

Assumptions include location scope, effective date, review date, source type, confidence, and formula compatibility. Results use ranges where site conditions, prices, weather, or behavior materially affect the answer.

Primary public pages focus on the strongest solar and electricity calculators and guides. Supporting routes remain usable while their data, examples, sources, and review notes continue to improve.

Calculators are planning tools. Solar results are not engineering designs, certifications, guaranteed savings, or binding quotations.

Calculator methods begin with explicit user inputs, then apply documented units, ranges, and formula versions. The result pages expose the assumptions that most affect the estimate so readers can replace planning defaults with bill, roof, equipment, or quotation evidence when available.

Editorial reviews distinguish Philippine primary sources from international technical references. Philippine utility, regulatory, and market claims use locally applicable sources where available; international sources are identified as general technical context and are not presented as Philippine rules or prices.

Material errors can be reported through the corrections page. A correction is checked against the affected formula, source, visible wording, and related pages before publication, and significant formula changes receive a new version rather than silently changing an earlier method.