Inverters are a very important component of any solar panel system. In the past, string inverters have been the most commonly used on the market: they’re the original technology, and are also the most economical option. But in recent years newer inverter technologies, including microinverters and power optimizers, have been on the rise.
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.
While microinverters and power optimizers provide many of the same benefits, the two technologies also have many differences.
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.
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 typically has a warranty between five and 12 years. If this is a concern for you, extended warranties for inverters are often available for an additional cost.
Maintenance requirements differ for microinverters and power optimizers. With microinverters, you will have more electrical components on your roof. If a microinverter fails, an installer or electrician will need access to the roof to replace it. However, the other microinverters will continue to function and the system will continue to generate electricity. In general, microinverters tend to have relatively high maintenance costs.
If a power optimizer fails, roof access will still be needed to repair it. During that time, failure is more likely to occur at the central inverter, which means that the solar panel system will stop producing electricity. Typically, the central inverter will need to be replaced after 10 to 12 years.
Both microinverters and power optimizers are compatible with battery storage. However, depending on whether the battery stores DC or AC energy, 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 and power optimizers have very similar efficiencies, are good for monitoring individual panel performance and can help maximize energy production on complicated roofs. But your preferences will ultimately determine which option is best for your home.
If you are concerned about having too many electronic components on your roof, power optimizers would be a good choice. Alternatively, if you want an inverter option with a longer lifespan or dislike the aesthetics of central inverters, microinverters can be a good option 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 no shade, string inverters are the way to go.
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.