String inverters connect multiple solar panels in a series. Power is routed to a single inverter, where it’s converted to AC, then distributed to your main electrical panel and out to your home.

Because of how the solar panels are linked, if one of them is obstructed, whether from leaves, dirt or shade, it affects the production of all the other panels in that string, too. String inverters will cap the electricity production of each panel at the level of the lowest-producing panel, which means your whole system loses production. Sort of like that one light on your holiday light string failing and all the other lights turning off.

This design also creates a single point of failure—if the inverter goes out, your home cannot use any of the electricity produced by the solar panels. When this happens, troubleshooting and repairing are more complex, usually requiring a complete inverter replacement. This can result in weeks of zero solar energy production.

String inverters are often paired with DC power optimizers on the back of each panel to meet electrical codes. The optimizers track peak panel output and regulate voltage before power is sent to the string inverter. This can help maximize energy production and reduce the impact of shading.

String inverters are more applicable for solar panels placed on simple, flat surfaces. For example, they're often used for utility-scale systems where a lot of energy is being produced in a field with little to no shading.

Microinverters like the Enphase IQ8 do the same thing as string inverters—convert DC to AC—but in a different way. Installed on the back of each panel, they do the DC to AC conversion right at the panel, and then send the AC to your main electrical panel to distribute to your house.

Unlike string inverters, microinverters operate independently of one another. So if one panel has an obstruction like shade or even fails altogether, all the other panels continue to work normally and to their full potential. With microinverters, you keep getting the most possible power for your home, your battery continues to charge and work normally, and the impact to your solar production is minimized. 

Microinverters also make monitoring and troubleshooting easier, and panel-level performance insights allow quick diagnosis of any issues. If there's a problem, the fix can often be a simple swapping out of the microinverter since they have a plug-and-play design. But with extensive testing and a 25-year limited warranty, issues are exceptionally rare. In fact, the failure rate of Enphase IQ8 Microinverters is only 0.05%. Plus, the panel-level configuration makes it very easy to expand your system if your electricity needs change over time.

Another key advantage of Enphase Energy Systems with microinverters is their built-in rapid shutdown capability. In an emergency, the system can be shut down quickly and easily with a single switch. This helps protect first responders and anyone in the home.

Expanding a solar system with microinverters is significantly easier and more convenient compared to a traditional string inverter system. With microinverters, there’s no need to upsize or replace a centralized string inverter when increasing your system’s capacity. Instead, you simply add new solar panels and pair each one with its own microinverter. This modular approach not only simplifies the expansion process but also ensures that the new panels integrate seamlessly with your existing setup, allowing your system to grow with your energy needs.

String inverters
 

Pros:

• Easy to troubleshoot at the inverter
   
• Lower upfront equipment cost
   
• Easier system design on simple roofs
   

Cons:

• Inverter presents a single point of system failure
   
• Harder to troubleshoot at the panel level
   
• Production affected by shade or single-panel issues
   
• Expansion requires the replacement of the string inverter
   
• All panels in a string must be oriented in the same direction
   
• Additional equipment needed for rapid shutdown
   
• Only 10-12-year warranties and lifespans of 15 years or less 
   

Microinverters
 

Pros:

• Every solar panel operates independently
   
• Monitoring for every solar panel
   
• Better for complex roofs with many panels
   
• Easy system expansion (panels, batteries, EV chargers,)
   
• Lifespan of 25+ years  
   
• Easy replacement
   
• Meets rapid shutdown requirements
   

Cons:

• Can be more expensive upfront, but more value over time
   

As you can see, a string inverter might be okay for a simple system on an unshaded roof. But whether your system is simple or more complex, or you anticipate your electricity demand will increase over time (buying an EV or converting from gas to electric appliances) and require system expansion, Enphase microinverters are the way to go. 

Enphase guarantees IQ8 Microinverters for 25 years; the same as most panel warranties. They also use our breakthrough Burst Mode technology.

Enphase IQ8 Microinverters are simply more reliable, productive, and provide higher value than string inverters over time.