Solar Panel Inverter

Also sometimes referred to as a “centralized” inverter, the string inverter is the most common type of solar power inverter used in residential solar energy systems in the United States. It’s also the simplest and most cost-effective type of inverter on the market. In a string inverter system, groups of solar panels are linked together in series and connected by “strings.” Each string is then wired back into a single, centralized inverter that is typically located in a garage, a basement or mounted to the side of your home.

String inverters are simple, time-tested and easy to maintain, but they aren’t ideal for all applications. String inverter systems are only capable of producing as much electricity as their least productive panel, so your entire solar system could potentially be compromised by just one or two panels that are shaded or otherwise not producing as much energy as they should. For this reason, string inverters are best used in systems that are mounted to simple roof structures and that receive consistent, uninterrupted sunlight throughout the day.

Whereas string inverters provide a single, centralized inverter source, micro-inverters convert your solar panel energy to AC in a more decentralized manner. In a micro inverter system, each individual solar panel is fitted with its own small inverter right at the site of the panel. This configuration provides several benefits. First, because each panel has its energy inverted individually, there’s no risk of one or two panels bottlenecking the production of your entire system. Second, micro-inverters make it possible to monitor the performance of each solar panel separately.

Unfortunately, micro-inverter systems are also considerably more expensive than string inverter systems. The distributed nature of the system also makes it more difficult and costly to repair, as there are more potential points of failure and the hardware is mounted directly to the roof itself. For these reasons, micro-inverters are typically only cost-effective in specific situations. This includes systems that have solar panels facing multiple directions, homes that have complex roof shapes and systems that are at risk of shade-related bottleneck issues.

If neither of the previous solar system inverter options sounds quite right for you, there’s also a middle ground between the two. Power optimizer systems can be thought of as a hybrid option, offering some of the benefits of micro-inverter systems at a lower price point. Like micro-inverters, power optimizers are either built into each individual panel or installed on the roof next to them. However, rather than converting the electricity from each panel to AC, power optimizers “condition” the DC electricity to ensure that the total energy output is consistently maximized. The energy is then fed into a centralized inverter similar to a standard string-type system.

As with micro-inverters, this setup limits the impact of panel shading on your overall system. It also allows you to monitor the performance of each individual panel. However, while the cost is lower than a micro-inverter system, it’s still more costly than a basic string inverter system. It also presents the same maintenance and repair difficulties as micro-inverters. Because of this, a power optimizer system is a good compromise for anyone who wants the benefits of a micro-inverter system at a somewhat lower up-front cost.