How this site makes money

When you click a link to Amazon on this site, the address carries an identifier that tells Amazon the visit came from us. If you buy something during that visit, Amazon pays us a percentage of the order. The money comes out of the retail price the merchant already charges, so the total on your screen does not change.

Two parts of this site earn nothing. The calculators run in your browser from files we publish, and they do not send what you type anywhere. The wattage tables are our own collection of figures from public sources, and they carry no links to shops.

We also link out to standards bodies, government agencies and manufacturers. Those are plain links. They exist so you can check a number, not so we get paid.

Not every link on this site is monetized. The table below shows the four kinds you will meet and what happens when you follow one.

Every Amazon link opens in the same tab and carries both rel="nofollow" and rel="sponsored". The sponsored value is the machine readable half of the disclosure you are reading now.

We do not print prices. Amazon requires retailers to show live prices, so a static number would be out of date within a day. Every product link says Check current price, and the real figure lives on Amazon's own page.

We do not publish scores we have not earned. We have not bought or run the equipment on this site, so we do not claim that we did. Where a manufacturer publishes a specification we cite it and date it. Where we are estimating, we say so in the sentence, not in a footnote.

We do not sell placement. No brand can buy a higher position, a longer entry, or a mention in a calculator result. Nobody reviews a page before it is published.

We do not run paid reviews dressed as editorial. If we ever publish something a brand paid for, it will say so at the top of the page in plain words. So far we have published none.

A product gets a place because it fits a load profile we can compute, not because it pays well. The order never changes. Work out daily energy in watt hours, running watts and startup surge first. Then look for hardware that covers all three with some margin.

When two products meet the same requirement, the tie is broken by specifications a reader can verify: surge rating, usable capacity, input limits, warranty length. The commission percentage is not part of that decision, and we do not sort by it.

This is also why some lists on this site are short. When only one product in a category meets the numbers and the certification requirements, the list has one entry. Padding it out with products that fail the check would waste your money to make ours.

Appliance figures come from energy labels and manufacturer specification sheets, collected into our own wattage table. Each row records where the figure came from and the date we read it. Sun hour figures are long run averages for a region, not a forecast for your roof.

Each calculator links back to the page its assumptions came from, so a number can be traced instead of trusted. If the label on your own appliance disagrees with our table, your label is right. Type its figure into the calculator and the result moves to match.

We label estimates as estimates. A figure marked typical or planning value is a starting point for a calculation, not a measurement of your house.

This page was first published on 2026-11-02. If the way we earn money changes, this page changes before anything else does, and the date at the foot of the page moves with it.

This page describes our commercial practices. It is not legal advice, and it does not replace the terms Amazon applies to your own order.

How the numbers on the site are produced and corrected is set out on the method page. Who publishes the site is on the about page, and what you agree to by using it is on the terms page.