Contact HelioCalc

Corrections and data questions

If a number on this site is wrong, the fastest route is to send the page URL, the exact statement, and a primary source we can verify — an EIA table, an IRS document, a utility tariff sheet or a program handbook. Material corrections are logged publicly on the corrections page rather than applied silently.

What we can help with

• Questions about a formula, a default or the 2026 federal credit treatment.
• State data corrections with a citable source.
• Accessibility problems with the calculator or tables.
• Suggestions for a calculator or guide that is missing.

What we cannot help with

We cannot review an individual installer contract, prepare a tax return, determine your eligibility for a specific program, or tell you whether to buy a system. For those, use a licensed contractor, a tax professional and your utility.

What happens next

Corrections are checked against the primary source before anything is changed. If the report is confirmed, the affected pages are regenerated together with every other page that shares the same data, and an entry is added to the corrections log with the date, the old value, the new value and the pages involved. If we disagree, we will say why and point to the source we relied on. Because this is a small independent project rather than a support desk, we do not promise a fixed response time, but material errors in a computed figure are handled ahead of feature requests.

Email

[email protected]

Please include the page URL in the subject line so a correction can be traced to the affected pages. Do not send utility account numbers, Social Security numbers or installer contracts.