Ptc Rating Of Solar Panels

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.

Ptc rating of solar panels.

Ambient temperature at 10 meters above ground level and wind speed of 1 meter per second. Because the stc rating is a measurement calculated under ideal laboratory conditions it s not always a useful metric for designing your system. Meaning the normal expected pv condition expected on a utility scale project. Stc standard test condtions and ptc pvusa test conditions are the two methods of testing module performance.

If a solar panel has 20 percent efficiency that means it s capable of converting 20 percent of the sunshine hitting it into electricity. So what is ptc rating on a solar module and how is it used. 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. The average efficiency of solar panels falls between the 17 to 19 percent efficiency range.

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. 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. The highest efficiency solar panels on the market today can reach almost 23 percent efficiency. And as panels cool their output goes up this type of power drop off happens for all panels.

Ptc power rating power ratings measure a solar panel s power output in watts. Although ptc ratings offer a realistic view of photovoltaic output they don t indicate exact energy production. Ptc is often referred to as pvusa test condition but more explicitly it is photovoltaics for utility scale applications test condition. As the panel heats up as they all do in the real world its output drops.

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