There are 2 different types of solar inverters worth noting. They both have their benefits and drawbacks, some of which are outlined below.
- String Inverters
- Micro Inverters
A solar system with a string inverter only has 1 inverter converting energy from DC to AC. This type of inverter requires modules to be connected in series (called a string). Multiple strings can then be connected in parallel which then are connected into 1 inverter.
Since there is only 1 inverter, this piece of equipment can be placed anywhere around your home or site location. This allows for easier serviceability and increased speed of installation. These systems are in general less expensive than micro-inverter systems.
These inverters have electrical input properties that limit the # of modules that can be strung together in series, directly affecting your system size. This in turn could limit whether a system can work on your home/project or not.
If shading is present on any of the modules, the entire string's output of power is affected, lowering your overall system production.
There are other pieces of equipment than can help alleviate some of these stringing and shading issues (DC optimizers), which are discussed in another section.
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Micro inverters convert an individual solar module's DC output directly into AC. That means that each module's output is independent. If 1 module is compromised in any way, it won't affect any of the other modules.
Each module is isolated and independent of all the others in the system. Modules can be placed in any azimuth or tilt. This allows for greater flexibility when trying to design a system in confined areas or projects that have shading issues.
These systems are usually more expensive for a few reasons. Each module needs a microinverter. The cost/watt is much higher than a standard string inverter. Also, maintenance can be a bit more challenging if malfunctions occur. These inverters are located under the module, most likely on the roof. A repairman would need to climb on the roof and replace the microinverter instead of fixing a single inverter on the ground.