Editorial standards

These standards apply to every guide and calculator on the site.

Sourcing

• We use primary and authoritative sources: EIA, NREL, IEA, IRENA, Ember, the US Department of Energy, EPA, USGS, national laboratories, peer-reviewed research and manufacturer data sheets.
• Every statistic carries its data year, and every page lists its sources.
• We never invent quotes, figures or studies. If a number cannot be verified, we leave it out or label it clearly as an estimate with its assumptions.

Balance

We cover the advantages and the limits of every energy source, including intermittency, land use, materials, wildlife impacts and cost. We distinguish what is confirmed, what is reported and what is projected.

Calculators

Each calculator shows its formula, uses stated default assumptions you can change, and is backed by automated tests against hand-worked examples. See the methodology.

Updates and corrections

Pages show the date they were last updated. Electricity prices and fast-moving statistics are refreshed when new official data is released. If you find an error, tell us; confirmed errors are corrected promptly.

Independence

Advertising and any future affiliate links never influence what we write or the numbers our calculators produce. We will disclose affiliate links clearly where they appear.