The Most Efficient Solar Panels Available on The NZ Market

Update 2024: This page is as old as the sands of the Sahara! Solar panel efficiency now ranges between 20 to 24%.  See the latest solar panel models here.

Comparing the efficiency specifications of solar panels is a great way to select the appropriate panels for your needs.  While highly efficient solar panels are definitely a plus, high efficiency isn’t the be-all and end-all; I’ll explain more in a moment.

First, let’s understand what solar panel efficiency actually means:
The efficiency of a solar panel is the amount of sunlight that a solar panel can convert into usable energy given the solar panels surface area that is exposed to the sunlight.

Simply put, it’s a percentage that calculates the panels ability to turn light into electricity.  The higher the percentage, the more sunlight it converts into electricity.

Each brand and model of solar panel is tested in a laboratory with controlled test conditions, such as light intensity and temperature.  Scientists determine how much power is created from each solar panel, with the same amount of solar panel surface area exposed in each test.

How efficient are solar panels in New Zealand?

All solar panels are assigned a percentage, this percentage represents how much power can be converted from sunlight into electricity.  Solar panels in New Zealand currently have an efficiency ranging between 18% and 22%.

As the science around solar panels improves, so does this percentage.  In 2015 My Solar Quotes looked at the average efficiency of panels available at that time, which was roughly 16%. 

The most efficient solar panel available in New Zealand is SunPower's 410W Maxeon 5 AC panel, with an efficiency of 22%.

Below is a list of solar panels presently available in New Zealand for 2022, and their respective efficiency ratings:

The Solar Panel with The Highest Efficiency Isn’t Necessarily the Best Pick, Here’s Why. 

The more efficient the solar panel, the more expensive they tend to be.

A solar power system with less efficient panels often needs a few extra panels for it to produce as much electricity as a system with highly efficient panels.  How much power a system produces is one the most important determining factors for how valuable it is, and with lower efficiency panels it may take an extra panel/panels to help bring the value up. 

If free roof space isn’t an issue, then choosing a lower efficiency panel could be advantageous if the price is better. But if space is limited a higher efficiency panel would be a better choice to gain maximum solar power.

When purchasing a solar panel, efficiency isn’t the only factor to consider.  Other factors include brand preference, warranty and aesthetics etc.  Click here to review our full solar panel buying guide.

Solar Panel Vs. Solar Panel.  Why is One More Efficient?

Silicon type, reflection and selected backsheets are just some of the factors that can affect the efficiency of a solar panel.

• Silicon type - there are three main types of solar cells; monocrystalline, polycrystalline, and thin film.  Monocrystalline is the best silicon structure for solar efficiency, whereas thin film is a lot less efficient (and hardly ever used for rooftop solar installations).  Cheap thin-film solar sheets are usually found on the top of caravans and powering calculators.
• Reflection - When sunlight hits the surface of a solar panel, some of the sun’s photons are reflected, which means a loss of potential energy.  There are ways to minimize the amount of light reflected away from the solar panels. For example, different treatments to the silicon allow the crystals to absorb more sunlight. Anti-reflective glass in front of the silicon cells can help absorb more of the sun’s energy as well.
• Backsheet - The backsheet’s colour can affect efficiency.  A black backsheet is often chosen for its aesthetics but it does absorb more of the sun’s heat, therefore heating up the solar panel, which reduces the efficiency.  It’s best to keep the solar panels as cool as possible to gain the maximum amount of solar from them.

Advice For Shopping Around And Comparing Solar Panels

Most solar installation companies will only stock two brands of solar panels.  To compare what’s on the market we recommend checking out a few different companies and compare solar panel brands and models that are available in New Zealand. To make life even easier check out My Solar Quotes Free, 3 Solar Quotes. By getting 3 free quotes from My Solar Quote’s online form, you can easily compare different solar panels that are available, contrast their efficiency ratings, and figure out the cost that works best for your solar project.