Ptc Rating Of Solar Panels

They are very important when more than one solar panel is to be used together in an array.

Ptc rating of solar panels.

The ptc of solar panels with stc rating of 260 watts varies in the gosolarcalifornia table from 217 1 watts ptc stc 0 835 to 239 8 watts ptc stc 0 922. For example a solar panel that had a manufacturer provided stc standard test condition or labeled rating of 100 watts would have their panel tested by pvusa and might be given a ptc rating or pvusa rating of 89 4 watts. As you can see the canadian solar 260 watt polycrystalline module has a ptc rating of 239 1 watts and an stc rating of 260 watts. Stc standard test condtions and ptc pvusa test conditions are the two methods of testing module performance.

Although ptc ratings offer a realistic view of photovoltaic output they don t indicate exact energy production. And as panels cool their output goes up this type of power drop off happens for all panels. Ambient temperature at 10 meters above ground level and wind speed of 1 meter per second. Generally if no ptc value is listed in the specifications for a photovoltaic panel you can expect it to be about 10 to 15 percent less efficient than the stc rating.

Ptc is often referred to as pvusa test condition but more explicitly it is photovoltaics for utility scale applications test condition. So what is ptc rating on a solar module and how is it used. Every panel is assigned a nameplate power output value which is measured using stc standard test conditions. If a solar panel has 20 percent efficiency that means it s capable of converting 20 percent of the sunshine hitting it into electricity.

The highest efficiency solar panels on the market today can reach almost 23 percent efficiency. Ptc power rating power ratings measure a solar panel s power output in watts. The stc and ptc ratings of solar panels are one of the ways of comparing the performance of one brand and or type of solar panel to another. As the panel heats up as they all do in the real world its output drops.

Because the stc rating is a measurement calculated under ideal laboratory conditions it s not always a useful metric for designing your system. Factors that affect solar panel efficiency. The ptc rating represents a more real life condition of 1 000 watts per square meter solar irradiance 1 5 air mass and 20 degrees c.