When buying a solar panel system, it is important to take solar efficiency into consideration. On the Australian solar market, you will find panels that vary greatly when it comes to performance and cell efficiency.
Here we will explain everything you need to know about this, and why it is so important to consider it.
First: What is solar efficiency?
Solar efficiency is the solar system’s ability to transfer energy from sunlight into electricity via photovoltaics. The higher the solar efficiency is the more solar electricity it can produce per m2 of solar panels.
On average, the efficiency of the cells in the solar panel system is somewhere between 15 and 22%. If a solar panel system has 22% efficiency, this would mean that the panels are able to convert 22% of the sunlight that hits it into electricity.
Why can’t a solar panel be 100% efficient?
A solar panel is not able to convert 100% of the sunlight that hits it into electricity because not all energy from the solar spectrum is absorbable. The solar panel can’t process certain wavelengths of the solar light. This light doesn’t reach the panel due to reflection.
How important is the efficiency of the solar panel?
The short answer to this is “very”. The efficiency of the solar panel will directly affect the solar panel output (how much power your solar system is able to produce). The better the power output is, the more money you will save.
If the power output is high, you will not have to use as much electricity from the grid as you would with a low power output. The self-consumption rate will get higher. You might also sell more power to your power provider, and earn more from feed-in tariffs.
What factors may affect solar efficiency?
When buying a solar panel system, it is important to consider these factors:
Output tolerance
The output tolerance given by the manufacturer can affect the panel’s performance and will tell you what performance you can expect of the panel’s watts rating. In most cases, the output tolerance is +/- 3%.
Temperature
Temperature affects the efficiency of a solar panel system. The warmer the solar panel is, the less efficient it will be. The installation type, ambient temperature and the temperature coefficient will all affect the solar panel’s output.
Grime and dirt on the solar panel
As time goes by, you should expect grime and dirt to cover the solar panels. As this will reduce the amount of sunlight that hits the solar cells, you can expect dirt to affect solar power in a negative way.
By cleaning the panels on a regular basis, you can ensure better panel performance. This job should be done by professionals.
Roof orientation and panel tilt
A solar panel should be angled in a way that makes the sunlight hit it directly, as this will ensure higher solar efficiency. Both roof orientation and the tilt of the panel can affect the efficiency of the panel significantly.
The installer will place the solar panel using an optimum tilt and angle, based on how the sunlight hits your rooftop.
The efficiency of the inverter
The solar panel system has an inverter, and this component will convert DC power to AC power which can be used by your home appliances. This conversion process is never 100% efficient, and the average efficiency loss is around 5-8%.
Solar battery efficiency
Some Australians have a solar panel system that includes a battery (a hybrid or stand-alone solar system). Note that the battery usually will not be able to operate at its given wattage. Usually, there will be an 8% efficiency loss from the solar battery.
What solar panels are most efficient?
In most cases, the solar panels that are considered to be best quality-wise, are also the most efficient ones.
On the Australian market, the SunPower Maxeon 3 (400 W module) is said to be the most efficient solar panel model for residential use. This model boasts an efficiency rate of 22.6%, which is really good.
Other well-known solar panel producers like REC and LONGi, also have highly efficient solar panel models that boost efficiency rates of 21% or more.
Here is a list of highly efficient solar panel models you might want to consider:
- SunPower Maxeon 6 – 22.8%
- Canadian Solar HiHero – 22.8%
- REC Alpha Pure Series – 22.2%
- Panasonic EverVolt – 22.2%
- Trina Solar Vertex S – 21.8%
- Jinko Solar Tiger Neo – 22.6%
Choose a system with high solar efficiency
Are you planning on going solar? If so, you should focus on finding a solar panel system of high efficiency. A solar panel installer will help you find the best system for your household. Good luck!