Comparing microinverters vs. inverters with power optimizers
Last updated 8/5/2020
Inverters are a very important component of any solar panel system: while solar panels convert sunlight into electricity, inverters ensure that the electricity they produce is usable in your home. There are three primary types of inverters: string inverters, inverters + power optimizers and microinverters. String inverters are the oldest technology: they are a proven, durable and cost-effective option that have been installed for decades throughout the world. Microinverters and power optimizers are newer technologies and have been on the rise in popularity over the last decade, especially on the residential market, for their ability to improve the performance of systems that experience shading or that are on complex roofs.
It is important to note that power optimizers are not inverters, while micrroinverters are. This means that the best apples to apples comparison is between microinverters and a string inverter plus power optimizer system. However, given that the pros and cons of string inverter systems are well known, we focus in this article specificcally on the performance provided by adding power optimizers to a central inverter and compare that to the performance of microinverters on rooftops.
Microinverters vs. Power optimizers: Compare and contrast
Microinverters and power optimizers are very comparable and are sometimes described as interchangeable in the industry. They are collectively referred to as “Module-Level Power Electronics,” or MLPEs.
Similarities Between Microinverters and Power Optimizers
- Microinverters and power optimizers improve performance for solar panels on complicated roofs, or roofs that experience marginal shading during the day.
- Both microinverters and power optimizers can monitor the performance of individual solar panels.
While microinverters and power optimizers provide many of the same benefits, the two technologies also have many differences, as explored in greater detail below.
Top 5 Differences Between Microinverters vs. Power Optimizers
1. Where the DC converts to AC
If you choose to install microinverters with your solar panel system, one microinverter will be placed at each panel, either integrated into the panel or placed on the panel mount. In systems with microinverters, the DC energy is converted to AC right at the site of the panel.
Like microinverters, power optimizers are installed at each panel. However, instead of converting the DC energy to AC at the panel, the optimizers “condition” the DC energy and send it to a central inverter that finishes the conversion process. The conditioning process fixes the voltage of the DC energy so that the central inverter can more efficiently convert it to AC energy. Systems with power optimizers are more efficient than the standard string inverter option under shading scenarios.
As time goes on, both microinverters and solar optimizers are becoming more cost-competitive with other inverter options. That being said, microinverters tend to cost more than power optimizers in today’s market.
Power optimizers are also the less expensive option in terms of scalability. In general, as solar panel systems get larger, the cost per watt decreases. However, if you choose to install a system with microinverters, you have to purchase a microinverter for every additional solar panel that you add to your system. If you choose to install a system with power optimizers, your system will still use one central inverter. As a result, your cost per watt will decrease as your system size increases.
Both microinverters and power optimizers have 25-year warranties. However while optimizers are warrantied for 25 years, the central inverter that they are paired with may have a shorter standard warranty. Installers often offer an extended warranty on the central inverter, either as part of their package deal or at an additional price.
Over the lifetime of inverters and power optimizers, you need to consider if and how many times they’ll fail, as well as how much of your solar production will be impacted in the unlikely event that they fail. In the event that an individual inverter fails, it will likely cost more to replace a microinverter or a power optimizer on a roof than it will to replace a string inverter on a wall at ground level, given the need for roof access.
However, that’s only part of the calculus around life-time maintenance costs. The leading microinverters are warrantied for 25 years, whereas many string inverters are warrantied for only 12, implying that you might have to replace your inverter mid-way through the lifetime of your solar panels. Additionally, it's important to take a close look at what's included–and what's not–in a company's warranty terms. Does the company cover installation labor, replacement and the shipping of parts? And what is the claim process like for getting a warranty processed? All of these are important considerations when choosing the type of inverter to install on your property.
5. Battery Options
Both microinverters and power optimizers are compatible with battery storage. However, depending upon whether you want to DC or AC couple your battery, it may need to be paired with a particular type of inverter. If you’re considering battery storage, it’s a good idea to talk to your installer or electrician about which inverters would work best with your battery of choice.
Microinverters vs. Power optimizers: Choosing the right option for your system
Microinverters and power optimizers have very similar efficiencies, are good for monitoring individual panel performance and can help maximize energy production on slightly shaded or complicated roofs. But your preferences will ultimately determine which option is best for your home.
It’s important to keep in mind that microinverters and optimizers certainly aren’t the only options available – if you’re looking for the most economic option and have a south-facing roof with little shade, string inverters are the way to go.
Compare your inverter options to find the best match
You have the power as a consumer and a solar shopper to explore both your microinverter and power optimizer options. Start by reviewing the different manufacturers offering the two types of technologies. Then register your property on EnergySage – our network of pre-screened, vetted installers will provide you with no-obligation quotes that you can easily compare side-by-side to find the best solar panel system to fit your needs.
EnergySage is the nation's online solar marketplace: when you sign up for a free account, we connect you with solar companies in your area, who compete for your business with custom solar quotes tailored to fit your needs. Over 10 million people come to EnergySage each year to learn about, shop for and invest in solar. Sign up today to see how much solar can save you.