How Efficient Are Solar Cells

Updated: August 29, 2023

Solar panel efficiency measures how well solar panels convert sunlight to usable electricity.

Solar panels efficiency is about 19.2% on average, ranging between 16% to 22%. In Australia, solar panels have a much higher efficiency of between 25% and 25.54% due to the high amounts of sunshine.

The more efficient a solar panel is, the more power it produces. Different types of solar panel brands have different rates of efficiency. Carry out extensive research before you purchase your solar panels.

Manufacturing technology

There are many solar panel manufacturers in the market. Each claims the highest efficiency.

Over time, solar panel manufacturing technology has developed. It has led to highly efficient solar panels.

In the last decade, as manufacturing technology has improved, solar panels have achieved as much as 22% efficiency.

There are three types of solar panels you can get on the market. First, monocrystalline solar panels. They are made with the purest silicon. They are the most advanced technologically and have the highest efficiency.

Second, polycrystalline solar panels. They are not as efficient as monocrystalline solar panels. However, they are more affordable.

Third, thin film solar panels. They are based on old technology and are the least efficient of the three types.

Manufacturing technology

Available sunlight

Solar panels convert sunlight into usable electricity.

The longer the solar panels are exposed to the sun, the more electricity they produce. Thus, solar panel efficiency is affected by the availability of sunlight.

Australia enjoys sunshine most days all year round. Different regions have more sunshine than others. The efficiency of solar panels will vary in different regions. Solar panels will be more efficient in regions of higher sunlight availability.

The CEC has divided the country into four parts based on the amount of sun in each region. Regions with more sunlight enjoy higher rebates than those with less sun due to the efficiency of the solar panels.

Solar panel installation and orientation

Improper installation of solar panels leads to their loss of efficiency. Thus, you should always have a professional install the panels for you.

One of the factors to consider when installing solar panels is the angle of installation or tilt. Depending on where you live, solar panels are not installed flat on the roof. They must be tilted to a particular angle to ensure that they can absorb as much sunlight as possible.

The wrong angle affects how much sunlight reaches the solar panels and, how much electricity is produced.

Orientation is the direction in which the solar panels are installed. East-facing solar panels are more efficient in the morning when the sun is in the East. West-facing solar panels are more efficient in the afternoon until the sun sets.

Consult a professional for the best orientation of your solar panels.


Solar panels must be exposed to sunlight at all times to enhance their productivity. Shade reduces the working of your solar panels.

When installing solar panels, ensure that they are away from shade. Depending on the design of your solar system, shade on one solar panel affects the productivity of the whole system.

Shade reduces how much sunlight gets to your solar panels. Consequently, it reduces how much usable electricity they can produce.

A professional installer will carry out a site inspection before panel installation. It helps the installer to know which parts are affected by shade and how to design the solar panels installed.


Different seasons have a different impact on the efficiency of solar panels.

In hot seasons, solar panels are highly efficient due to the availability of sunlight. In cold seasons, the panels produce less electricity due to poor sun exposure.

At night and on cloudy days, solar panels produce less electricity. You will need a solar battery for these days.

A solar battery stores excess power from the solar panels. The stored power can be used these days when the panels cannot or produce less power.

Age and condition of solar panels

Solar panels have a 25-year lifespan. The older the solar system, the less efficient it is.

Installing a new solar PV system loses 20% of its efficiency in the first ten years. The remaining 80% is lost as it ages.

After 25 years, your solar panels will lose their electricity production capacity and have to be replaced.

Additionally, you will need to clean or remove dust from the surface of your solar panels.

When the dust accumulates, it hinders the amount of sunlight the panels can absorb. It reduces the efficiency of the panels.

Clean your solar panels at least once every year.

Solar inverters

Solar inverters are the other core component of a solar power system.

Solar inverters convert the sunshine captured by the solar panels into usable Alternate Current electricity that can power the home lights and run appliances.

Solar power technology ensures that you will only need a single solar inverter for up to ten solar panels installed on your rooftop.

Thus, you don’t need much space to set up your home power generation station.

Solar panels and inverters are bought together. They are affordable and easy to install if you engage Clean Energy Council-accredited installers.

For a high-efficiency solar system, get the requisite inverter capacity. It will ensure that you have maximum power production at all times.

Benefits of high-efficiency solar PV system

Solar PV System | Matt Montagne | Flickr | CC BY-SA 2.0

Benefits of high efficiency solar PV system

Higher amounts of electricity produced

The more efficient solar panels are, the more electricity they produce. Highly efficient solar panels absorb the sun easily and produce more power than less efficient solar panels.

Depending on the size of your solar panels, more efficient solar panels will produce more electricity.

Quick ROI

The more efficient a solar panel is, the more power it produces. As a result, the faster you can recoup your investment in the system.

With higher power production, especially for commercial use, the bigger the savings on your electricity bill. It contributes to a faster recovery of your initial investment.

Additionally, you will not need to buy many solar panels if you use highly efficient solar panels.

The cost of a solar system depends on the number of solar panels you need. The fewer panels you require, the less you invest, and the faster your ROI.

Lifetime productivity of the system

High-efficiency solar panels produce more power over their lifetime than lower-efficiency solar panels.

As they age, more efficient solar panels will produce more power than lower efficiency panels.

Thus, you will have more efficient solar panels for longer. You may have to replace the low-efficiency solar panels before their estimated lifespan is over.

Climatic conditions

Depending on the climatic conditions of where you live, high-efficiency solar panels produce power even in less than ideal conditions.

High-efficiency solar panels can produce sufficient electricity for your home even with a few hours of little sunlight. They will provide power even on cloudy and cold days.

How to save money when buying solar panels

Buy the right size of solar system for your home

The larger the solar panels you purchase, the more you spend.

Assess your electricity consumption or daily power needs before you purchase a solar system.

Buy an upgradeable system

When buying your solar system, it is essential to consider your future power needs.

In the future, you may need a larger-capacity solar system for your home as you may have more power needs.

Talk to your installer so that you can get an easily upgradeable system.

To upgrade your solar system, you may require a few extra solar panels and maybe a battery system.

The additional solar panels will have your system increase its capacity, the battery system will help store the excess power to enhance the availability of more power when you need it.

Government incentives

To get a solar panel rebate when you buy solar panels, you must purchase them from Clean Energy Council Accredited installers. It will ensure that you get up to $3,000 off on your purchase, depending on the size of your solar panels.

The larger the solar system, the higher the rebate you will likely receive.

You can also get low-interest loans to purchase and install solar panels in your home.

Get quotes from different installers

Before purchasing solar panels, find out how much they cost from different installers.

Different brands of solar panels cost differently, even for the same size of solar panels.

Getting several quotes ensures you know the price range of the required solar system size.

Factors to consider when buying solar panels

Size of solar panel

The size of a solar panel is defined according to its rated power output efficiency. The bigger the solar panel, the higher the price.

Choose a solar panel size based on your power consumption.

Your choice of installer

Different solar panel manufacturers and installers offer different prices for their solar panels.

Before you purchase a solar system, get several quotes from installers. Also, read customer reviews of the different installers that you would want to use.

The brand of solar panel you choose to buy

With more Australians adopting solar use, many solar panel brands are on the market.

Check the rated efficiency of the solar panels you choose before you buy.

Also, ensure that you buy from an accredited retailer or installer.

Government rebates

New solar panel customers in Australia enjoy government rebates that help to lower the cost of solar panels.

How much you get as a rebate depends on the size of the solar panel that you purchase.

The rebate amount ranges from $1000 to $5,400 depending on the size of the solar panel. The bigger the solar panels the higher the rebate.

Hire a pro to install your solar system

If you want to install a new solar system, here is a free tool that you can use. is a free tool that connects homeowners to accredited solar panel installers.

  1. At the top of the tool, enter your zip code.
  2. Then, fill out the subsequent form to provide more information on your house size and electricity consumption.
  3. You will then receive three quotes from professional installers with no obligation to hire them. Compare the quotes and choose one of the installers to install the solar system for you.
solar mobile free service hand

Ben McInerney head shotAuthor: Ben McInerney is a renewable energy enthusiast with the goal of helping more Australians understand solar systems to make the best choice before they purchase. Having an accredited solar installer in the family helps give Ben access to the correct information, which allows him to break it down and make it easily understandable to the average homeowner.