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What is solar panel efficiency?

Panel efficiency is the measure of the ability of solar panels to generate electricity from the sun’s light. The rate of panel efficiency is a percentage expression of its efficiency to aid in comparison with different panels and/or comparison with its earlier output. For example, if a panel has a 30% efficiency rate, it means that it has the ability to convert 30% of the sunlight it receives into electricity.

Sometimes a household does not require much energy output for their property, then it is more beneficial for them to get lower-efficiency solar panels as their power needs are smaller. Investing in high-efficiency panels is more sensible when the energy output you need for your property is high.

Panel efficiency differs for each panel type

1) Monocrystalline

Monocrystalline panels have the highest rate of efficiency of about 15% – 25%. Their average life expectancy is also the highest at more than 35 years. They perform at an excellent efficiency rate way beyond their warranty years. These panels require very little roof space. Even though monocrystalline panels have a higher initial cost than other panel types, people like to invest in them for their durability and high return on investment.

2) Polycrystalline

These panels are less expensive and less efficient than monocrystalline panels. The average efficiency rate of these panels is 11% to 17% and their average lifespan ranges between 25 to 35 years. These panels require more roof area than monocrystalline ones and are less heat tolerant than them too.

3) Thin Film

These panels are the least expensive alternative of all and have the shortest payback period. The average rate of efficiency of thin film panels is 10% to 20%. Their life expectancy is lower than both other types of solar panels. Thin film panels have low space efficiency as they require the most amount of roof space to function well making them unfavorable for domestic installation. They are more heat tolerant than the other types.

Factors that affect solar panel efficiency

Other than the panel type, there are some factors that affect the panel’s efficiency.

1) Reflection

When a panel reflects sunlight instead of absorbing it for power generation, its efficiency is lesser. Many solar companies use anti-reflective films to improve panel efficiency.

2) High temperatures

When temperatures soar too high, a panel’s performance is reduced. The ideal temperature for solar panels to perform is between 59°F to 95°F. When it gets hotter than 130°F, the efficiency is reduced.

3) Wiring

Different panels have different wiring and electrical parts. Any discrepancy during installation can result in production loss. Improper wiring and mismatch between panels and inverters can considerably impact the efficiency of your system. It is therefore always advised to buy the best quality solar panels and solar inverters in Australia from the same solar company in Gold Coast to avoid inconsistencies resulting in any loss of efficiency.

4) Shading

Hindrances like trees and other buildings around the property causing shade on the panels will affect solar panel output depending upon the length of time and size of the shadow.

5) Solar cell type

A solar cell is an electrical component on the inside of the panel which converts the sun’s light into usable electricity. Most solar cells are made up of crystalline silicon. Monocrystalline panels are made up of single silicon crystals while polycrystalline panels are made of multiple crystals. Solar cells made from single crystals are more productive than those with multiple crystals. Thin film panels are built with amorphous silicon. The atoms here are put in a random arrangement as opposed to a more orderly crystalline layout, resulting in lesser efficiency.

6) Debris

Dust, bird droppings, pollen, etc. gathered on the panels’ surface obstruct sunlight which results in lower panel efficiency.

7) Weather and climate

Areas with plenty of sunshine are more profitable for solar energy production than places with more overcast skies, rain, and storm.

8) Roof angle and direction

The efficiency of your panels has a direct relationship with the angle and direction of your roof. North-faced solar panels in Queensland give maximum power output. The east and west-facing solar panels in Queensland produce excellent output too. A south-facing roof is the least beneficial for solar production in Australia.


With solar panels in Queensland operating at their peak efficiency, you can get faster payback on your solar. Therefore, you should consider getting the most out of your system by taking care of the factors that impact its efficiency.

Do get in touch with Solar Power Nation for the best in the industry system recommendations and a variety of solar services. We hire only CEC-accredited installers to do the jobs!!

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