Advantages & disadvantages of microinverters & power optimizers
Last updated 7/15/2020
Centralized string inverters are still the most common technology option for rooftop solar panel systems in the United States. However, microinverters and power optimizers (often referred to as module-level power electronics, or MLPEs) have recently gained in popularity. But are microinverters or power optimizers right for you and your solar panel system?
Micro-inverters and power optimizers offer similar benefits but operate in different ways. Both are mounted next to individual solar panels and prevent performance issues if one or more of your solar panels are shaded. The key difference is that microinverters convert the DC electricity generated by your solar panels into the AC electricity that your household appliances use, while optimizers “condition” the DC electricity before sending it to a central inverter.
Both microinverters and power optimizers are premium products that come at a premium price. If your roof receives little to no shading, or if your panels are being placed on only one or two different roof planes, they may not be worth the extra cost.
- String inverters are generally the most affordable inverter option and function best when your roof is ideal for solar.
- Microinverters and power optimizers are best suited for roofs that have shading or solar arrays with panels oriented in multiple directions.
- Because micro-inverters and power optimizers are more efficient than string inverters, a system that uses them will produce slightly more power than a similar system with a string inverter under shading scenarios.
- Because there are more electronic components, microinverters and power optimizers may require additional effort to repair. However, if a malfunction does occur, the loss is more likely to be isolated to a single panel and does not cause the entire string–or even system–to stop producing power.
- If you are considering getting a solar power system with micro-inverters or power optimizers, pay careful attention to whether the additional cost is worth it to you.
Advantages of microinverters & power optimizers
MLPE technologies offer the following advantages over centralized string inverters:
- If one of the solar panels in a system is underperforming, MLPE devices ensure that your system still produces a substantial amount of power. With a central string inverter, power generation on an individual string can fall if a single panel stops producing power. With MLPE systems, the output from each panel is optimized independently and does not affect the performance of the others.
- They are a good option for complex roofs that face multiple directions. With string inverters, panels in the same string must have the same orientation so that each one has the same power output. Multiple strings can be connected to the same inverter, so if you are placing panels on two different roof planes, a string inverter may still be the right choice. Otherwise, the added cost of MLPE is worth it.
- They allow you to monitor the performance of individual solar panels, usually through a smartphone app or web portal. This makes for quick identification of problems and easy troubleshooting.
- They often come with longer standard warranties than string inverters – up to 25 years when they are integrated with solar panels. Warranties vary by manufacturer, but in many cases, manufacturers will offer extended warranties at an additional price or as a loyalty perk to their installer network.
Remember that, although microinverters and power optimizers are more efficient, they are not always a better investment. If you pay significantly more to get a system with microinverters or optimizers, you can get more power out of your panels if your situation isn’t quite ideal for solar, but it won’t always translate into a greater return on investment or shorter payback period. Get an instant estimate of solar savings with EnergySage’s Solar Calculator, or register your property to get solar installation quotes from qualified installers at no cost.
Disadvantages of microinverters & power optimizers
The potential disadvantages of microinverters and power optimizers are primarily in regards to maintenance and reliability, rather than how well the devices convert DC electricity to AC.
- MLPE technologies have higher costs than string inverters.
- More equipment means more potential points for breakdowns. While string inverters may not deal with shading as well as MLPE technologies, the upside is that a system with a string inverter includes fewer pieces of equipment.
- MLPE devices do their work in a relatively harsh environment. Your roof is exposed to the elements year-round. With micro-inverter and power optimizer systems, all or most of the critical equipment sits on the roof through rain, snow and heat. By comparison, string inverters are generally located off of the roof.
- Maintenance and replacement may require more effort. In the event of a problem, a technician will need to access the roof to make repairs. Depending on your maintenance plan and warranty, this may cost you money.
Microinverters and power optimizers are a premium product, but they come at a premium price. Spending the additional money for microinverters or power optimizers isn’t always necessary. They are the best option where partial shading or a complicated roof would negatively impact solar panel system performance. If you have an uncomplicated, unshaded roof, a string inverter can provide better value.
You should always shop around and compare the cost and savings associated with various equipment options and their cost and savings. Register your property on the EnergySage Solar Marketplace today to receive solar quotes from multiple pre-screened solar installers near you.
Comparison table: String inverters, microinverters & power optimizers
|String inverters||Microinverters & power optimizers|
|Warranty||10+ years||25 years (panel-integrated)|
|Performance when some panels are shaded||Lower||Higher|
|Performance on "complicated" roofs||Even, or lower||Even, or higher|
|Amount of electronics on roof||Fewest||Most|
|Performance with "complicated" solar panel arrays||Lower||Higher|
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