Okay, so you’ve decided to invest in a solar system. Maybe you’re tired of those high energy bills, or maybe you want a smaller carbon footprint – whatever the reason, you’re here and you’re looking for information.
But the internet is full of varied information and content creators that have biased opinions (and we, of course, are just as biased in our views).
You probably came across some strong opinions about the differences between microinverter systems and string inverter systems. There are benefits and drawbacks to each type of technology.
At Penrith Solar Centre, we specialise in microinverter solar systems (told you we were biased) and are experts in their installation. We only sell what we put on our own homes. There are advantages to microinverters that range from safety to efficiency.
In this article, you will learn:
- How microinverters optimize system performance.
- The safety advantages of microinverters.
- The wonderful world of monitoring systems.
- Microinverter system reliability.
- The benefits of expanding your system.
As you navigate the journey to harness the power of the sun, you’ll need to understand this technology so you can make informed decisions that align with your energy goals.
By the end of this article, you’ll be better informed about microinverter solar systems and their benefits.
How Do Microinverters Optimise System Performance?
Unlike traditional string inverter systems, microinverter solar setups offer a distinctive advantage: panel-level energy optimisation. An individual microinverter can maximize the energy output of your solar panels because each panel operates independently.
Each microinverter in a microinverter solar system is mounted underneath each solar panel. The purpose of each microinverter is transforming the direct current (DC) power harvested from the sun into alternating current (AC) power that can be fed into your home.
By optimizing each panel’s output, microinverters make the most of available sunlight. Shading or obstructions on one panel won’t significantly affect the entire system’s output. If one panel is in the shade or covered by some autumn leaves (for instance), the other panels keep operating at full capacity regardless of what the others are doing.
The system is decentralised, which eliminates the central point of failure you might find in a string inverter solar system. If you’re interested in learning more about the differences between microinverter solar systems and string inverter solar systems, you might want to check out the following article titled, Microinverters vs. String Inverters: An Honest Comparison.
Why would you want your solar system decentralized? Here’s a fun metaphor: Think of a 20-panel solar system like a freeway.
With a string inverter, you’re only using one lane. You might be doing 100 kilometres an hour and you might be producing 5,000 watts, but all twenty “cars” are in that one lane. If the first car slows down, then all the cars slow down and drive at the same speed as the slowest car. The whole system slows down.
With microinverters, you’ve essentially got 20 lanes (if you have twenty panels). Each panel has a microinverter installed in it, a “car.” And that car is doing 100 kilometres an hour, producing 5,000 watts. Each car has a lane of its own because the system is decentralized and each microinverter is operating independently as it converts DC power to AC power. If one car slows down, it doesn’t affect the other cars in the other lanes. The other cars can keep going and once the slow car is replaced or repaired so it can hit the road once again.
What Are the Safety Advantages of Microinverters?
Before getting into the specifics of AC versus DC, it should be stated that the number one guarantee of safety in your solar system is the install. Have a qualified and certified solar installer who is knowledgeable of safety practices will make sure that your solar system is designed and installed with safety in mind.
If you’re interested in learning more about how your installer will affect your solar system, you might want to check out the following article titled, In-house Installers vs. Subcontractors: Which is Better?
Microinverter solar systems are safer. Full stop. This isn’t an issue of brand versus brand. This is science. The issue is direct current versus alternating current.
Microinverters convert DC power into AC power for each panel before sending that electricity down to the home.
String inverters convert DC into AC, and it is usually located on the side of the house. In a string inverter system, the electricity is in DC form for a longer period of time. Instead of being converted to alternating current immediately at the solar panel, it travels from the roof to the inverter on the side of the home and through wiring.
If anything happens to that wiring, it’s going to be far more dangerous in DC form than AC.
Why is that?
If the cable is severed, the arc (which is the distance the electrical shock jumps from one frayed end to the other) will spread depending on how much power is going through that cable. DC arcs are far more likely to start a fire.
The power in a DC cable will remain live in the cable and will continue arcing and cause a fire. This is because the power is steady, as depicted in the graph included above. The DC power is a steady directional current that continues uninterrupted.
If an AC cable is damaged, it will trip the circuit breaker and shut down the microinverters (and the whole system) immediately.
If you’re interested in learning a bit more about how microinverter solar systems work and how they create and export power to your home, you might want to check out the following article titled, How Do Microinverter Systems Work?
How Do Microinverter Monitoring Systems Help Performance?
One of the reasons a microinverter system outperforms its competitors is the advanced monitoring system that is included with the purchase of your solar system. It puts the power (pun intended) of the system in your hands.
A monitoring system will tell you when you’re using energy during the day and when you’re selling it back to the grid for a feed-in tariff. It reports how your system operates. When you’re looking at feedback from that app, ask yourself “How do I use this information to increase my self-consumption so it will lead to long-term savings?”
Real-time performance tracking allows you to quickly identify any underperforming panels due to shading, dirt, bird and bat faeces, or any possible malfunctions. By pinpointing these problems and identifying which microinverter and which panel are misbehaving, you can promptly correct the system to restore optimal performance.
Monitoring systems detect and diagnose failures quickly in your solar system.
One of the advantages of solar is that it requires little maintenance, and the parts are covered under warranties. But how do you know what to repair and replace?
A microinverter system monitoring app will diagnose whether it’s the panel or the microinverter. Repairs are easy. If a microinverter fails on a 20-panel roof, then only 5% of your system is down. The other 95% of the system is still working and producing energy until the microinverter is repaired.
When a string inverter system fails, 100% of the system goes down. There’s no individual monitoring system and it’s impossible to remotely diagnose the system because of how it’s constructed. When the system fails, a technician to be called to the site to diagnose the problem. Then the part must be ordered, which takes time. Shipping is next, clocking more time. Then the installer returns to the site again to fix the system. Your string inverter system could be down for weeks or over a month.
How much will you be paying for electricity during that time?
Monitoring systems also provide historical performance data, enabling you to analyse energy production trends in your system over time. You can compare the performance of panels or microinverters and identify seasonal patterns.
If you’re interested in learning more about the effect of seasonal patterns on the performance of your solar system, you might want to check out the following article titled, Which Way Should Solar Panels Face in Australia?
How Are Microinverters Reliable?
Microinverters are incredibly reliable pieces of technology. The reason they are so reliable is because they have no moving parts. Moving parts equal heat. Heat equals fatigue. Fatigue equals failure.
Microinverters are encased in a dense polymer housing that’s resistant to corrosion, is waterproof, and is dustproof. Inside the housing, everything is held in place by NORYL resin.
Without moving parts, microinverters run cooler than string inverters. If both a microinverter and a string inverter produce 7 kW of power, the microinverter will convert that energy from DC to AC on the roof and produce much less heat once it’s on the ground, which a string inverter can’t do.
Also (as we mentioned above) every microinverter is mounted underneath the solar panel which means they are never in direct sunlight.
Microinverters have an operating temperature of up to 85° Celsius (which is the sum of a 65° Celsius external temperature, plus the heat generated in the microinverter when the DC power is converted to AC). Most string inverters shut down at 50° Celsius. Enphase (who manufactures microinverters in Australia) did study here showcasing this ability.
What Are the Benefits of Microinverter Expansion?
Microinverter systems are inherently expandable. Adding more panels to your setup doesn’t require major changes to the existing infrastructure. You can gradually expand depending on your evolving energy needs or financial situation.
Because of a decentralized setup, adding more panels to the system doesn’t affect the existing configuration. New panels can be added, each with its own microinverter, without changing the existing wiring or setup.
The performance stays consistent when you add another array to another part of your roof. Connecting them is very easy. As opposed to expanding a string inverter solar array, which will likely require an entire second string of panels (who is the most cost effective now?).
If you’re interested in learning a bit more about the cost of microinverter solar systems, you might want to check out the following article titled, How Much Does a Microinverter Solar System Cost?
If your energy needs are low, investing in a microinverter system is a better starting point than a string inverter system. As your energy requirements evolve, your system can too.
Microinverter systems also offer the flexibility to start with a system based on budget. If you have limited space or funds, you can start with a smaller system and add panels in the future.
If you’re interested in learning a bit more about how microinverters save you money in the long run, you might want to check out the following article title, What is the Payback Period for Solar Panels in Australia?
Final Thoughts on the Benefits of a Microinverter System
In the evolving landscape of solar energy, microinverter systems are an innovation that offers a range of benefits. They optimize system performance. They’re safer than their competitors. The monitoring systems help you save on energy each month. They’re ridiculously reliable and expandable.
Now that you understand some of the benefits of microinverter systems, you might want to continue your journey to a greener future by reading up on how to evaluate your energy needs with the following article titled, How Much Solar Do You Need?