Functional unit Vs Declared unit

What is the difference between functional unit and declared unit?
My question is specifically about PV panels where functional unit is stated as 1Wp and there is a declared unit of 1m².

One example of EPD for PV panel:

Hi Mahdi!

We have an article on this specific topic on the help center. In short:

  • Think of the functional unit as measuring the effectiveness of the product.
  • Think of the declared unit as measuring the amount of the product.
1 Like