Solar maths, minus the sales pitch.

A named editor, not a content farm

SolarMath is written and edited by Marcus Hale, the site’s editor, who reviews every calculator assumption and every guide before publication. Marcus spent a decade in residential energy — first on installation crews, later auditing other companies’ quotes for homeowners — and started SolarMath after watching the same three estimation tricks appear in quote after quote: production modelled without system losses, savings projected on expired incentives, and export rules left unmentioned until the first disappointing bill.

The editorial rules are simple. Every figure on this site traces to a checkable source class: US Energy Information Administration rate data for electricity prices, published industry cost benchmarks for price per watt, utility tariff documents for billing rules, and annual-average sunshine data of the kind produced by national solar resource datasets. Where a number is an estimate, the site says so and shows the formula. Where the rules changed — most importantly the end of the federal residential credit after 2025 — the site says that too, loudly, because outdated incentive claims are the single most expensive error in solar shopping today.

What SolarMath is not

• Not an installer, broker or lead generator — we never sell your details to solar companies.
• Not paid by panel brands; no calculator result changes because of a sponsorship.
• Not a substitute for a site survey, an engineer’s assessment, or regulated financial or tax advice.

Corrections

Rates, tariffs and incentive rules change, and we would rather be corrected than current-looking. If a figure on SolarMath is wrong for your state or utility, tell us via the contact page with a link to the official source; verified corrections are made and noted on the page.