Efficiency can be associated with all things electrical, however solar panels command their own definition of 'efficiency'. Below you can find helpful explanations as to what is commonly referred to in the industry as "solar panel efficiency".
What is Solar Panel Efficiency?
It is the amount of energy produced in relation to the area of solar cells exposed to useable sunlight. A percentage is given to this ratio, then we are able to compare different solar panels based on this technical specification. Solar panel efficiency is often referred to as ‘solar panel conversion efficiency’, or an easier way to think of it is how much sunlight can be converted into power
What is a typical Solar Panel Conversion Efficiency Rate?
The range of solar panels on the market today has an efficiency rate between 14% and 21% conversion efficiency.
Efficiency of Solar Panels Available In New Zealand
Trina Solar’s PD14 – 290W – 16% panel efficiency
Mitsubishi Monocrystalline Premium – 270W – 16.3% panel efficiency
Renesola Virtus II - 260W - Module- 16% panel efficiency
Test Conditions for Measuring Solar Panel Efficiency
STC (standard test conditions) is the industry standard for testing the efficiency of solar panels. STC specify standard test conditions including the temperature of the solar panel, the solar irradiance and mass of the air.
Most solar panel manufacturers will publish the STC percentage on the specification sheets for their solar panels, which gives us a good indication of how one solar panel performs compared to another product.
Are High Efficiency Solar Panels Better?
Many customers appear to prefer higher efficiency solar panels, but at what cost? Higher efficient panels are more expensive, so it might be worth considering the value of the real estate and where the panels are going to be placed. If the solar panels are going on a large warehouse roof then the efficiency might not be so important, because you can just add more panels to reach the system size you want. If the solar panels are going to be on a solar power farm, where the land was specifically developed to house solar panels, then having higher efficiency and a higher output for each solar panel might be more important.