Micro Inverters vs Central Inverters
A solar inverter converts DC power captured by your solar panels into AC power that can be used in your home. The two types of inverters used in residential solar are micro inverters and central inverters with power optimizers.
While there are several excellent solar panels on the market, there are only two inverter brands that have the features and benefits needed for dependable solar. The best micro inverters are made by Enphase, and the best central string inverters are made by SolarEdge. But which is better?
Picking the best inverter comes down to a choice between SolarEdge vs. Enphase. You can easily compare how they rank in our solar inverter features table:
|Reliability||✔ No Single point of failure||Single point of failure|
|Warranty||✔ 25 years||12 years|
|Expandability||✔ Easy to expand||Limited by inverter size|
|Minimizes Clipping||Clipping at peak hours||✔ Easy to minimize|
|Customer Service||✔ Short wait time||Long wait on phone|
|Replacement Process||✔ Fast||More complex|
|Aesthetics||✔ No central inverter||Central inverter on wall|
|Battery Compatibility||Only AC-coupled||✔ Compatible with most|
|Cost||Usually higher||✔ Usually less expensive|
|Monitoring||✔ Panel level & great interface||Panel Level Optional|
|Design Flexibility||✔ Few limits to design||Stringing limitations|
Benefits of Micro Inverters
Microinverters are small inverters mounted under each panel, and they convert your DC power to AC right on your roof. A major advantage of micro inverters is that if a panel is shaded or stops producing, the rest of your solar continues to produce power. Another major benefit of microinverters is their flexibility of design including the ability to add more panels later without having to upsize a central inverter. You also get panel-level monitoring, giving you a detailed look at your system’s performance. Warranty periods for micro inverters are typically longer which is a reflection of their expected lifespan. Enphase’s IQ7 micro inverters have a 25 year warranty.
Drawback of Micro Inverters: Clipping
The biggest disadvantage of micro inverters is clipping. Clipping is when the panel output (wattage) is higher than the microinverter’s capacity to convert energy. For example, if you have a 100-watt lightbulb in a lamp that can only output 60 watts of light, 40 watts of light would be clipped. Similarly, if you have a 370-watt solar panel with a microinverter that can only handle 290 watts, 80 watts of power will be lost during peak hours of the day.
Keeping the range small between inverter capacity and panel output is critical. Don’t waste money on high wattage panels that are coupled with low output micros. The system price is a good way to tell because higher capacity microinverters are more expensive. Insist on seeing inverter output data sheets.
Central Inverter with Power Optimizers
Central inverters convert the DC power from your panels to AC power in a central unit mounted on a wall. Hybrid inverters like SolarEdge have power optimizers mounted on each panel to mitigate the effects of shading on an array. Central string inverters without power optimizers are like the old style of Christmas lights: when one panel goes down, all panels in the string go down. Power optimizers stop that from happening, and enable panel level monitoring.
However, if the central inverter goes down, you lose all the power from your panels connected to it. This single point of failure increases the chance that the entire solar system goes down when a failure occurs. While power optimizers reduce the effects of shading and underperforming panels on each string, they don’t help if the central inverter goes down.
Benefit: Less Clipping, Higher Efficiency
A major benefit of a string inverter is reducing or eliminating clipping if the inverter is sized properly. Many installers, however, tend to undersize central inverters, so be sure to check the inverter maximum capacity against your system output capacity. Another benefit of central inverters like the SolarEdge HD Wave is that it has a higher efficiency rating than microinverters. This means there’s a higher conversion rate of DC power into AC power.
Drawbacks Of Central Inverters
The big drawback with central inverters is the risk of losing all of your production if the inverter goes down because it is a single point of failure. Another major drawback is the inverter has only a 10 – 12 year warranty, but you can extend it up to 25, which we highly recommend. Many installers offer the extended warranty, so be sure to ask. Optimizers have a 25 year warranty.
The Best Solar Inverter: SolarEdge vs Enphase
What’s the Best Solar Inverter?
Enphase Microinverters is our top pick for the best solar inverter for residential solar systems, with SolarEdge coming in secondCalifornia Solar Guide
- Enphase Micro Inverters: Enphase is our pick for the best solar inverter. Enphase produces microinverters in different models for different panels. The micro inverters can be mounted in the field or in the factory (AC modules). Both Panasonic and Sunpower offer panels with factory-mounted Enphase micro inverters. See the Enphase family of microinverters.
- SolarEdge Inverter plus Power Optimizers: The industry standard for central inverters, SolarEdge’s HD Wave technology has reduced the size of central inverters. They’re less expensive than microinverters. They even have an integrated EV charger option, which is popular for homeowners with electric vehicles. If you get an LG Chem battery for energy storage, your only inverter choice is a SolarEdge StorEdge inverter. (LG is currently developing a proprietary inverter to couple with their flagship battery.)
Solar Monitoring: Enphase vs SolarEdge
Monitoring is a feature of your inverter, and the app you receive depends on the inverter you choose. The inverter manufacturer hosts your monitoring system. Your system monitoring shows the production of your solar. Enphase shows it on a panel level and array level. SolarEdge gives installers the option to grant access to panel level monitoring or not. Because they get more calls for service, many installers don’t grant access. Ask for it!
Keep an eye on your monitoring for any issues and to be sure everything is operating well. Installers aren’t always following their fleet daily. Since it’s your investment, you have the biggest interest in it.
Both have mobile phone apps and desktop platforms which are similar. I’ve set up hundreds of systems in both Enphase enlighten and SolarEdge monitoring, and Enlighten is more elegant yet simple too, so I give the nod for the best monitoring system to Enphase.
Do I Need Consumption Monitoring?
Consumption monitoring shows your power usage from both solar power and the grid. It requires a special connector that does’t fit in all electrical panels. There’s usually an additional cost for it, but it’s well worth it. With consumption monitoring, you don’t have to do the math between your solar monitoring and your utility bill. If your installer offers it, get it to see your consumption right in the monitoring portal.
Pro Tip: Get Consumption Monitoring
Why? Neither your net-metered bill nor your solar monitoring has the complete picture of your energy usage. Most people are confused that their utility bill does not match their solar production on their monitoring reports. This is because the utility company never sees all of your solar production, only the excess that flows into the grid.
Conversely, your solar production monitoring does not show how much power you pulled from the grid without a consumption meter. This is why adding consumption to your solar monitoring provides you with the big picture so all the numbers make sense.
Transferring Equipment Warranties
Most panels and inverters have transferrable warranties. Some charge a fee to transfer the warranty, others are automatic as they remain with the system itself. Enphase, for example, charges $299 to transfer the warranty when you sell your home.
Our Pick For The Best Solar Inverter
To summarize, the best inverter choice is a micro inverter system. While the best central inverter is SolarEdge, Enphase is the best micro inverter and the best overall inverter for solar. Due to the single point of failure issue of string inverters, Enphase systems are the most reliable choice for homeowners.
If you are choosing a high-power solar panel then you need to read the best inverter for high power solar panels because high wattage panels may lose power with microinverters. If you pick one of the best solar installers, they will help you make the right choice.