What To Look For On The Solar Panel Specification Sheet – So Over Rated!

Are you under the assumption that the 5kW system you have been quoted is what your system will produce? Then you need to read on to find out what really to expect!

To set the scene I do want to touch on the relationship between current, voltage, and resistance; the amount of sunshine hitting the panels and temperature increase of the panels, creates resistance. This is important because it affects how the panels perform, and they do not all perform the same.

To outline, and as I want to explain this as simple as possible, please excuse my non-technical language– Voltage is the driving force of the circuit, current is the electrons being forced around the circuit by the voltage; the rate of the flow of electrons is measured in amps, which it is this relationship that determines the amount of power that is being produced. This is important because as the panels heat up on your roof, the voltage reduces because the electrons become a little crazy causing resistance, and therefore reducing the power output of the panels.

So we need to know how the temperature or amount of sun may affect your proposed panels, and how to compare between panels from the data on their specifications sheet. We will look at data collected during the standard test conditions (STC), nominal operating cell temperature (NOCT) conditions, and the temperature characteristics to determine what can actually be expected from a typical panel.

Some figures on solar panel specification sheets can be misleading, so enable yourself to cut through the mumbo jumbo and inform yourself so you can select or reject a panel being proposed to you. The rated output of panels, that is quoted to you, is data collected in ideal conditions that are unlikely to be the situation on your rooftop. In fact, you will have factors affecting the output of your system all day long.

If you would like to read on further then please see the full article here which apparently is only a 6 minute read! There is too much information for here, and I need to show you pictures of the specification sheets to clarify what I am referring to. Go on read it, do yourself a favour!