Sources
For laws, we work from bill texts, official state and national sources (legislatures, utility commissions, government departments) and reputable trackers, and we state the date our information applies to. For products, we use manufacturer specifications, certification databases and independent reviews. For savings, we use long-term solar resource data and published electricity prices, and we show our assumptions.
Testing
Where we have tested a product ourselves, we say so and describe how. Where we have not, we say that too, and base our assessment on published specifications and independent data. We do not describe products as “tested” unless we have tested them.
Estimates
Figures such as yearly production, savings and payback are estimates. We label them as such, show the inputs, and encourage readers to use the calculator with their own numbers.
Updates
Plug-in solar rules change quickly. We review law pages whenever a bill moves and at least monthly, and we show the date of the last update. Product pages are reviewed when prices, availability or certifications change.
Corrections
If we get something wrong, we fix it and, for material errors, note the correction on the page. Please tell us if you spot a mistake.
Independence
We are not affiliated with any manufacturer, retailer or utility. Advertising and affiliate commissions do not influence rankings or conclusions. Manufacturers cannot pay for placement or review our articles before publication. How we make money.
Not professional advice
Our content is general information. It is not legal, financial or electrical advice. Check with your utility, landlord, local authority or a licensed electrician where appropriate.