Microinverter vs String Inverter? How to Pick With 1 Easy Question (Solar Inverters)

Georgette Kilgore headshot, wearing 8 Billion Trees shirt with forest in the background.Written by Georgette Kilgore

Solar Panels | March 15, 2024

While looking at microinverter vs. string inverter a man wonders how to choose between solar inverters and what’s the advantage of grid tie solar inverters, micro inverter solar panel and string inverter panels?

Microinverter vs string inverter can be a tough decision when choosing the perfect solar inverter system for your home.

Both inverters effectively help you convert DC to AC, but the problem is, what qualities should you look for when picking one?

Thanks to tech advancements over the last decades, you can now use solar inverters and maximize panel performance, but there’s one easy way to choose between the two.

When deciding between a microinverter vs string inverter options, it boils down to how dependent you plant o be on your solar energy system and how much money you want to spend.

However, since there is more than one difference between the two solar inverter designs, it’s always a good idea to compare both the advantages and disadvantages of each before making the final choice.

This complete guide to solar inverters can help.

Microinverter vs String Inverter, Which Is Better?

Microinverters and string inverters are equally effective in converting DC to AC, but each has an advantage over the other that makes it challenging to pick one.

An image depicting a comparison between microinverters and string inverters, two types of devices used in solar panel systems. The image is intended to showcase the benefits and drawbacks of each type of inverter and aid in the decision-making process for selecting the appropriate inverter for a specific solar panel system.

For instance, microinverters are the top choice for tech advancements and high performance, while string inverters win in affordability and easy maintenance.

Therefore, it is a close call between them, and the decision entirely relies on personal preference.

What Are Solar Inverters?

Before discussing the types of inverters and how they play out against each other, it is crucial to find out what is a solar inverter first.

Everything starts with the solar cells in your panels. When the sun’s rays hit the PV system, the electrons inside vibrate, creating direct current (DC).

When you learn how to wire solar panels, you will understand that the circuits in the cells collect the energy that powers your home.

Since households use AC (Alternating Current), the solar inverters’ main job is to convert the energy into a more usable form.

Physical hardware of a solar inverter including various ports and connectors for power input and output that convert direct current (DC) electricity produced by solar panels into alternating current (AC) electricity that can be used by household appliances and fed into the electrical grid.

(Image: Paul Krashefski, U.S. Department of Energy10)

You cannot solely rely on the energy from the panels, and the solar inverters turn it into electricity that can power all your household appliances.

Besides, if your system produces more power than you need, you can revert it to the grid in exchange for credits.

What Is a Micro Inverter?

Microinverters have a unique design to help your panels perform at their most optimal level by converting DC power to AC. Each is a tiny gadget that attaches beneath a solar panel, but you can find brands modify their inverters to link to 2-4 solar panels.

It is a more flexible system since each panel links to its inverter, and the best part is that it is easier to boost the output of each panel instead of focusing on how multiple panels work. Using MPPT technology, the voltage goes through each microinverter unit such that an issue with one panel doesn’t affect how others in the system work.

Related Reading: MPPT vs PWM Charge Controllers? How To Choose in 3 Quick Steps (See Chart)

This mode of operation makes it stand out from the sting inverter and works if the panels are facing different directions or if some panels are shaded. This way, only the affected panel with have issues while others usually work.1

A person preparing to install a microinverter onto a solar panel system on a roof.

(Image: Laksh Muchhal, U.S. Department of Energy11)

Ultimately, there is no single point of failure; one inverter’s issue doesn’t affect the entire solar power, which is a significant selling point for microinverters.2

Micro Inverter Solar Panel Pros and Benefits

  1. Rapid Shutdown: Microinverters have in-built capabilities to allow immediate shutdown whenever necessary to avoid the dangers of high voltage.
  2. Efficiency and Reliability: Given that each panel works independently, microinverters ensure that the entire system works regardless of a point of failure. Considering how much power does a solar panel produce, this inverter will improve the performance of the whole setup.
  3. More Power: Compared to stringing solar panels, letting them run independently has the advantage of facilitating more electricity, even when there are some differences in the energy from each panel.
  4. Accommodation of all Panels: Sometimes, there are issues with shading or heavy coverage, and you want the panels to face in different directions; the microinverters will allow it.
  5. Performance Tracking: Microinverters can track each panel’s performance, making it easier to make necessary adjustments.
  6. Ease of Expansion: You can always add a microinverter and a panel, a pair at a time, if you plan to expand the system.
  7. Lifespan: Microinverters come with 25-year warranties, meaning they will serve you longer than other inverters.

Downsides of Microinverters

  1. Cost: One thing new installer notice when buying microinverters is that they are pricier to buy and install. They cost about $1000 more than other systems since they feature expensive and high-tech equipment.
  2. High Maintenance: Given the elaborate design, a significant drawback of microinverters is that if one fails, you wouldn’t detect it, and it would be tasking to replace it.
  3. Excessive Hardware: Each microinverter links to a solar panel, meaning there will be a lot of activity on your roof. Since they can be tiny lightning rods, you should be especially cautious if you live in a stormy region.3

What Is a String Inverter?

A string/central inverter works differently from microinverters.

Instead of each linking to each panel, string inverters connect all of them in the system to a main component, forming a “string” of panels. This tech has been used for the longest time and has an impressive track record.

Depending on the design, the inverter can hold multiple panels simultaneously.

For instance, five panels can form three strings, meaning fifteen are in the system. All the strings connect to the central inverter to help boost their performance.

A 6-string inverter of a solar panel system showing several input and output ports that are connected to the solar panel strings and the electrical grid.

(Image: Scott Ely, U.S. Department of Energy12)

Generally, the larger the string inverter, the more panels in the system. If you know how to test solar panels and have the technical knowledge of how the setup works, you can experiment with string sizing (determining how many you can link to an inverter).4

String Inverter Solar Advantages

  1. Easy Troubleshooting: Given how simple the setup is, you will always know that the inverter is the problem if the system fails, and the central component makes fixing easier. It is also one of the most user-friendly systems.
  2. Low Cost: Unlike microinverters, central inverter systems are cheaper to install since there are fewer labor hours and less equipment to buy. Given how much do solar panels cost, this option will help squeeze your budget.
  3. Fewer Chances of Failure: Thanks to few connections in the entire setup, it reduces the chances of wiring mix-ups or poor connections.
  4. Low Maintenance: Central inverter systems are some of the easiest to maintain, given that fewer solar panel connectors types and equipment are involved.

Downsides of String Inverters

  1. Reduced Efficiency: The working principle of the central inverters makes them less efficient since the low performance of one panel interferes with the power output and the entire setup.5 One mishap quickly affects the whole chain, which is a problem in cases of partial shading.
  2. Monitoring Issues: You cannot track each panel’s performance if they are in a chain. You can only check the total power output, making it difficult to pinpoint which is defective or not working.
  3. Tasking Expansion: You must link new panels in a string together with a new central inverter if you have expansion plans. This process is tasking and costly compared to expanding when dealing with microinverters.
  4. Short Lifespan: string inverters have a relatively shorter warranty of only 8-12 years, meaning that you will have to buy a new one at some point after installing solar panels.

Microinverter vs Solar Inverter Pros and Cons

After closely looking at the individual features of the two inverter systems, you have a better picture of how they work and which will serve you best.

The following is a breakdown of the microinverter vs string inverter pros and cons based on various features.

Factor Microinverter String Inverter
Price Expensive Affordable
Monitoring Easy to track individual panel performance Impossible to remotely monitor panel performance
Troubleshooting Complex to troubleshoot Easy troubleshooting
Safety Rapid shutdown enabled No emergency shutdown
Efficiency More reliable Less efficient
Hardware It uses a lot of hardware6 A straightforward system with less wiring and hardware
Expansion Easy to expand More tasking to expand
Maintenance More complex to maintain Easier to maintain
Lifespan 25 years of service 8-12-year lifespan

The table above clearly indicates the winner based on various factors, and as a new user, you can use it to guide your decision.

Consider the features you are looking for and the dealbreakers, identifying what you expect from your inverter and what you cannot compromise.

Microinverter vs String Inverter, What Is the Difference?

The main difference between a microinverter vs string inverter is the performance. The central inverters link all the solar panels in a chain that attaches to a single inverter, while the microinverters link to one panel at a time.7

Microinverters have the advantage of allowing every panel to work independently, facilitating close monitoring of how each performs. On the other hand, the string inverter lets all the panels work as a team, and any hiccup affects the entire system.

However, its advantage over microinverters is that it is cheaper and easier to install and maintain.

What Is the Difference Between Grid Tie Solar Inverters and Regular Solar Inverters?

Grid-tie solar inverters help convert DC to AC while linking your home’s power supply to the grid. It works like a standard inverter, ensuring that the electricity from the PV cells powers your appliances but at the same time switches to the grid when the solar power is insufficient.

Four central inverters situated under a wooden structure with solar panel systems in the background.

(Image: Scott Ely, U.S. Department of Energy13)

However, standard or off-grid inverters don’t work with the grid; they only provide your home with usable solar power. They work independently to draw power from the batteries and transform it to AC which runs your house’s appliances.

Microinverters vs Optimizers, What Is the Difference?

While microinverters convert DC to AC, the optimizers don’t; their job involves conditioning or fixing the DC’s voltage to allow the string inverter to convert it to AC. Unlike microinverters, they don’t actively perform the conversion.

Graphics of types of solar panel inverters showing how solar panels are connected to home through a string inverter, microinverters, and power optimizers.

Secondly, microinverters have more extended warranties, unlike optimizers which attach to string inverters with shorter lifespans, meaning you may have to replace optimizers sooner than microinverters.

What Is the Cost of Solar Inverter?

On average, solar inverters usually cost $1000-$1500 for a standard setup size, but the cost can be higher depending on the installation’s size. Considering the total cost of the entire project, from the price of the panels and other equipment, experts estimate that the solar inverters should cost $0.18 a watt.

Accounting for all other factors, the rate could drop as low as $0.09 or be as high as $0.27. Typically, the inverters should cost 6% of the total installation cost, costing an average of $ 0.18 a watt.

Microinverter vs String Inverter, Which One To Choose and Why

No solar inverter system is perfect; each has a fair share of ups and downsides, and as a user, the best you can do is to weigh them carefully. It is advisable to have a checklist of what you are looking for to help you narrow down the options.

For instance, microinverters are your best bet if you are going for high efficiency, reliability, and easy monitoring of individual panels. However, you will have to consider that they are more expensive to acquire and install due to their design.

Similarly, your top choice would be the string inverter if you want a cost-effective solution that is easy to troubleshoot and maintain. However, this decision means losing out on features like emergency shutdown and individual panel performance monitoring.8

Therefore, your version depends on your budget, what you want in an inverter, and your preferences. Regardless, both are effective systems that help you convert DC from your panels to AC that powers your devices.

Microinverters and string inverters are practical tools to help convert the DC your panels harness into AC that runs your household. They are unique systems with differing working principles, and deciding between them can be challenging.

While central inverters are simple equipment that is easy to install and maintain, microinverters are more efficient.9 The latter may also be very effective but more expensive and complex to install and troubleshoot than string inverters.

The two have their up and downsides and compelling selling points.

Therefore, the winner in the microinverter vs string inverter war is based on perception; which appeals more to you?

Frequently Asked Questions About Microinverter vs String Inverter

Are Microinverters Worth It?

You can invest in microinverters if you are looking for high performance and efficiency in conversion. They are ideal if your region has weather challenges and your panels have shading problems because they will keep working regardless of the hiccups.


References

1Burke, D. (2023, January 13). Microinverter vs string vs optimizer: A solar inverter guide. A&R Solar. Retrieved March 29, 2023, from, <https://www.a-rsolar.com/blog/microinverter-string-inverter-optimizer/#pros-micro>

2Rojas, D., Muñoz, J., Rivera, M., & Rohten, J. (2021, September 28). Review of Control Techniques in Microinverters. National Library of Medicine. Retrieved March 29, 2023, from <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8512252/>

3Sendy, A. (2023, March 24). Pros and cons of string inverters vs microinverters. Solar Reviews. Retrieved March 29, 2023, from, <https://www.solarreviews.com/blog/pros-and-cons-of-string-inverter-vs-microinverter>

4Chaaban, M. A. (n.d.). Stringing PV inverter. PennState. Retrieved March 29, 2023, from <https://www.e-education.psu.edu/ae868/node/906>

5WAARE. (2022, August 16). Pros and Cons of micro inverters vs string inverters. WAARE. Retrieved March 29, 2023, from, <https://www.waaree.com/blog/micro-inverter-vs-string-inverter>

6Solar Energy Technologies Office. (n.d.). Solar Hardware. Office of ENERGY EFFICIENCY & RENEWABLE ENERGY. Retrieved March 29, 2023, from <https://www.energy.gov/eere/solar/solar-hardware>

7My Generation Energy (2021, January 21). Microinverters vs. Central Inverters: What’s Best?. My Generation Energy. Retrieved March 29, 2023, from, <https://www.mygenerationenergy.com/2021/01/21/microinverters-vs-central-inverters/>

8Go Green Solar (2022, April 29). Microinverters vs. String Inverters: What’s the Difference?. Go Green Solar. Retrieved March 29, 2023, from <https://blog.gogreensolar.com/solar-101-whats-the-difference-between-microinverters-and-string-inverters>

9Solar Energy Technologies Office (n.d.). Solar Integration: Inverters and Grid Services Basics. Office of ENERGY EFFICIENCY & RENEWABLE ENERGY. Retrieved March 29, 2023, from <https://www.energy.gov/eere/solar/solar-integration-inverters-and-grid-services-basics>

10Solar inverter hardware attached to the rooftop array Photo by Paul Krashefski, U.S. Department of Energy / U.S. Government Works. From Flickr <https://flic.kr/p/YjkLgX>

11Solar rooftop installation Photo by Laksh Muchhal, U.S. Department of Energy / U.S. Government Works. From Flickr <https://flic.kr/p/Y2LfUo>

12String inverters Photo by Scott Ely, U.S. Department of Energy / U.S. Government Works. From Flickr <https://flic.kr/p/Y2Lgw5>

13Four central inverters and associated switchgear Photo by Scott Ely, U.S. Department of Energy / U.S. Government Works. From Flickr <https://flic.kr/p/XNgifB>