Do I Need a Power Optimiser?
A power optimizer is an electrical device added to a solar system to improve its efficiency. Power optimizers are considered to be MLPE (module-level power electronics). The condition and fix the voltage of the DC energy then sends it to an inverter where it is converted to AC energy. Power optimizers are usually paired with centralized string inverters as they cannot invert energy on their own.
A power optimizer increases the efficiency of electricity generation of your solar system if your roof is complicated or prone to partial shading during the day. It also allows you to monitor the performance of individual modules for easy troubleshooting, repair, and maintenance.
So, if your modules are prone to mismatch loss due to degradation, partial shading, or manufacturing tolerance, a power optimizer will eliminate these issues and boost energy production.
There are several reasons to use power optimizers. These include:
- When you want to monitor the performance of your panels, power optimizers will help you know how individual panels are performing. This allows for quick troubleshooting and repair of specific panels.
- If your panels are facing different directions due to a complicated roof, a power optimizer ensures maximum performance of each panel whenever they are hit by sunlight.
- Power optimizers also optimize power production for roofs that experience marginal shading during the day.
With a power optimizer, your solar system will be more efficient and durable.
How do power optimisers work?
Typically, the sun hits PV solar panels which then create DC electricity that is sent to central string inverters for conversion into AC energy. However, complicated installations and roofs with marginal shading issues may reduce the power output of the panels. Power optimizers use the maximum power point tracking (MPPT) technology to improve the efficiency of each solar panel.
Power optimizers are usually installed at the rear side of individual solar panels and turn them into smart modules. These devices track the peak power output of the panels in real-time and then regulate or condition the voltage before sending the electricity to the central inverter.
This optimizes the performance of individual solar panels in your system regardless of their orientation, damage, or shade.
Which power optimiser do I need?
Before you choose a power optimizer, you should consider the factors below.
Efficiency
Power optimizers have different efficiencies, just like solar panels. The efficiency of a solar optimizer is measured by how much energy is lost when energy is being converted from DC to AC. Optimizers with higher efficiencies are the best to buy as they will offer more solar energy production.
Price
Power optimizers are not as expensive as solar panels, but it is essential to know how much they cost. Usually, power optimizers with longer warranties and higher efficiencies will be costlier than optimizers with lower efficiencies and shorter warranties. The device you choose will depend on your budget and preference.
Warranty
Most manufacturers offer a 25-year warranty for their power optimizers. This warranty protects consumers in case of manufacturing defects. Also, string inverters paired with the optimizers come with a separate warranty that may last between 5-15 years. Ensure you read the warranty agreement of several products before purchasing them.
Size
Solar optimizers and inverters are available in different sizes designed for different electricity voltages. Generally, larger optimizers and inverters will be costlier than smaller ones. Ensure the optimizer and inverter you buy suit your system.
Do I need to use a Solar Inverter with a power optimiser?
Yes, you should use a solar inverter with a power optimizer to make sure all the DC energy produced by each panel becomes converted into AC energy. The power optimizers track the maximum power output of the panels in real time. It then conditions and soothes the DC electricity before sending it to the solar inverter. This ensures the inverter processes more electricity, which increases the power output of your solar system.
Are power optimisers safe to use?
Absolutely yes! Power optimizers come with a safety voltage function designed to automatically reduce the DC voltage of the solar panels to a safe level (usually 1VDC) in case of the following scenarios:
- When the grid power or inverter shuts down
- The optimizer and modules become disconnected
- When the system becomes faulty
- When the inverter or safety switches are turned off
Your power optimizers can also be grounded depending on city regulations or racking components.
Does a power optimiser work on days with bad weather?
Yes, power optimizers can still work during bad weather. These devices are designed to function in harsh weather conditions, but their efficiency becomes lower than on days with favorable weather. More so, with the MPPT tracking technology, your solar system may have a better performance during bad weather than systems without microinverters or solar optimizers.
If a single panel is completely shaded, the power optimizer for that panel may shut down temporarily. This will, however, not affect the performance of the other power optimizers.
What are the advantages and disadvantages of power optimisers?
Power optimizers have several advantages and disadvantages, as outlined below:
Advantages
Increased efficiency in partially shaded panels
Solar panels that are partially shaded or installed on roofs with several angles tend to have a lower DC output. A power optimizer increases the output of individual panels that experience shading or do not get direct sunlight. This increases the overall power output of your system.
Monitors individual panels
Solar optimizers are MLPEs that collect and feed solar energy production data such as peak efficiency and output voltage from each panel to the cloud. You can then get updates on the performance of individual solar panels in real time.
Smaller inverter size
Voltage cleaning and tracking occur at the individual panel level, which means the inverter will be smaller. This makes power optimizers an excellent choice for homes with limited installation space.
Disadvantages
High installation cost
Power optimizers are installed on each solar panel, which means every solar module will have its own optimizer. This increases the installation cost compared to the traditional string inverters.
Different warranties
The standard warranty for power optimizers is 25 years, but the inverters paired with them have a warranty of 5-15 years. This can be frustrating as you may be forced to replace your inverter before your solar panels.
Limited inverters
Solar inverters are a new technology that is fast becoming popular for commercial and residential solar systems. However, finding a genuine inverter is quite daunting. SolarEdge is by far the only reliable manufacturer of inverters, and you cannot use other brands with their solar optimizers. This limits the options for customers that may want to explore other options.
Are power optimisers worth it?
Yes, power optimizers are a worthy investment for both commercial and residential solar arrays. If your site or roof experiences shading during the day, or you want to increase the efficiency of your solar system, power optimizers are an excellent option.
DIY vs. hiring a Professional
Installing power optimizers is not as complicated as most people think. If your solar panels are already installed, you can affix the inverter to the backside of the panel without a hassle. However, you must follow the installation guidelines carefully.
While DIY installations are cost-effective, they are prone to mistakes, especially if you are a beginner. It is better to let professionals do the installations for seamless results.
Do It Yourself
Below are the pros and cons of DIY installations.
Pros
- They are cost-effective as you will not pay for labor
- You will get an opportunity to hone your skills
- You get to decide which power optimizers to use and where to install the inverter
- You will feel fulfilled and satisfied after the project
Cons
- Higher risk of roof damage and leakages
- Physical danger due to inexperience
- It is time-consuming
- DIY is costly in the long run due to damages during the installation
Hiring a Professional
Some of the pros and cons of professional installations include:
Pros
- Professionals are experienced to install power optimizers
- Low risk of physical danger and damages to the modules, roof, and solar optimizer
- Pros will complete the installation within the timeline
- You will get warranties for the solar optimizers and inverter
Cons
- Professional installations are quite costly
- You may not be sure of the results
FAQ's
Are power optimisers better than microinverters?
Both power optimizers and microinverters are excellent options if you are looking to increase the efficiency of your solar panels. However, microinverters do cost more than power optimizers.
Besides, the cost per watt for power optimizers decreases as the systems get larger. This is because you can use one central inverter when you increase your system size, unlike microinverters, where you have to buy a new microinverter whenever you add a new solar panel.
How much does a solar optimiser cost?
A solar power optimizer costs around $70 to $100, depending on the size and type. The installation cost will depend on your location and the number of power optimizers you will need for your system.
Which power optimiser is the best?
SolarEdge is one of the best power optimizers in the market. This power optimizer increases the energy output of solar systems on complicated roofs and roofs prone to marginal shading during the day. The SolarEdge power optimizer individually tracks each panel’s MPPT (maximum power point) to make sure it works efficiently.
Author: 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.