From their efficiency and online ratings to the manufacturer’s decision, you need to consider a lot before purchasing 5KW solar system panels.


The average output range of solar panels is 200 to 350 watts. The highest performing panels have a higher power rating. These ratings might not always be reliable, but they are a great way to make comparisons between different panels when purchasing.

Power Output

In power output, consider the tolerance and efficiency of the panels.

Power Tolerance

This is the difference between the power rating on the solar panel nameplate and its actual power output. With a power tolerance of +/- 5%, a panel producing 250 watts could in truth only give 237.5 watts. Under the perfect conditions, the same panel can go as high as 262.5 watts. Smaller tolerance ranges offer more certainty.


This measures the effectiveness of a solar panel in converting sunlight to electricity, usually 20 percent or higher. The most efficient panels produce more kilowatt hours of energy.

Coefficient of Temperature

Did you know that high heat can be damaging to your solar panels? It seems implausible given that the panels are designed to be out in the sun all day. The temperature coefficient lets you know how your panels’ will be affected when the temperature goes higher than 77°F.

For every 4°F that the temperature increases above 77°F, most panels will reduce their output by 1 percent. Look for less sensitive temperature coefficients in our panels as they ensure higher performance.


The ISO 9000 (International Organisation for Standardisation) series are standards that assure the quality of solar panels. The certification is not necessarily an indicator of superior quality, but it is important to purchase certified products for a higher guarantee or performance.


You want to know how well the panels will survive and function over time when exposed to harsh conditions. Here are two durability metrics worth considering:

IEC 61215

This standard simulates decades of exposure to real-world conditions and anticipates any failure problems in the solar panels. Those panels that meet the International Electrotechnical Commission’s (IEC’s) 61215 reliability standard are more likely to outperform the rest.

Snow and Wind Load

Snow and wind both create extra pressure and weight on solar panels. Look for high snow and wind load ratings in panels as they will have a higher chance of tolerating additional weight.

Manufacturer Considerations

In the case of post-installation failure, a warranty covers your service needs.

Power Production Warranty

Over time, the solar panels will produce less electricity. A power production warranty assures you that the electricity output rate will not go below a certain percentage in the first 25 years of use, usually 80% or higher.
Manufacturers also provide a degradation rate of no more than 0.7% in their panels. This percentage guarantees that the power output diminishes only by a certain percentage within the first year of use.

Materials Warranty

This warranty guarantees that panel failure will not occur based on manufacturer defects. A materials warranty also protects you from failure due to environmental factors. The standard materials warranty range is 10 to 12 years, but some manufacturers go even further in promising the functionality of their solar panels.

Manufacturer’s Profile

The corporate profile will tell you, among other things if the manufacturer’s insurance coverage will survive even after they go out of business.

Take your time to understand all the factors involved while purchasing 5KW solar system.