TL;DR
Module wattage is the rated DC power a solar panel produces under standard test conditions, the headline number — currently 400 to 450 watts for typical residential panels — that multiplied by panel count gives system size. Real output runs lower than the rating because rooftops are hotter and dimmer than the test lab, which derates production 10 to 20 percent.
What it means
Module wattage is the rated DC power a solar panel produces under standard test conditions, the headline number — currently 400 to 450 watts for typical residential panels — that multiplied by panel count gives system size. Real output runs lower than the rating because rooftops are hotter and dimmer than the test lab, which derates production 10 to 20 percent. Quotes are compared on cost per watt, so this figure, the panel count, and the total system kW should reconcile exactly.
Where it sits in the glossary
Module wattage is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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