String inverters (also known as central inverters) and best for more simple solar systems. With a string inverter, groups of solar panels are connected to a ‘string.’ Several strings can be connected to one inverter. Energy flows from the panels to the inverter, which changes DC electricity into AC electricity before powering your home. String inverters are easy to manage because they’re often located in a home’s garage or basement, making them easily accessible. They’re also cheaper than other inverters because only one inverter is needed to accommodate multiple strings of panels.
A disadvantage of string inverters is that when one panel underperforms, it can affect the whole string of panels. Due to the inability to optimize each panel’s performance, string inverters are unsuitable for roofs with regular shading.
Small inverters are installed next to every solar panel with a micro-inverter system. Unlike string inverters, where power flows from every panel to one inverter before converting, micro-inverter systems convert DC electricity to AC electricity at each panel. Micro-inverters are best for houses with more complex panel designs or homes with regular shading, as the system maximizes each panel's performance to reduce shading effects.
Because each panel has its own inverter, micro-inverters make it easier to expand your system. String inverters are often sized based on the number of installed panels, which means they can’t handle additional electricity.
The biggest downsides of choosing micro-inverters are their price and maintenance. They’re more expensive than string inverters and are more challenging to maintain because they’re located on the roof.
Power optimizers are a mix of string inverters and microinverters. Energy from your solar panels goes to a central inverter like a string inverter, but each panel has an optimizer like microinverters. Power optimizers maximize electric voltage before sending energy to the string inverter. Since each panel’s electrical output is maximized, they reduce shading issues on panels.
Power optimizers are great for roofs with obstructions like gables and chimneys because they’re still able to maximize your system despite these challenges. However, just like microinverters, the biggest downside of power optimizers is their cost and maintenance. They tend to be more expensive than string inverters though they often cost less than microinverters. Maintenance is also more difficult because they’re on the roof, like microinverters.
A hybrid inverter has the advantage of being able to convert electricity in both directions. It can convert DC electricity from solar panels into AC power and AC power from the grid into DC energy for charging electric cars or solar batteries.
Hybrid inverters are popular among homeowners who want energy backup options because you can install them like regular inverters. However, you don’t collect additional costs when adding a battery to your solar system. After you install the battery, you can charge it with grid power and store it when solar power isn’t meeting all of your energy needs.
Disadvantages of hybrid inverters are their price and the types of roofs they can be used on. They’re more expensive than string inverters and aren’t ideal for roofs with complicated panel designs or areas with a lot of shade.