A Look at Micro-Inverters, String Inverters & Power Optimizers

Every solar power system requires a power inverter to convert the energy from the panels to AC electricity. There are three types of inverters, micro-inverter, string inverter or power optimizer, and each offers its own unique features and advantages. Choosing between them may come down to your needs, personal preferences or, simply, the system you choose.

Here’s a look at each of the inverters:

Power Optimizers

Over the past ten years, power optimizers have virtually taken over the inverter side of the residential rooftop solar energy market. Power optimizers are module-level power electronics (MLPE), also like micro-inverters, but have less electronics in the hot space on the back of the solar panels.  This leads to a lower failure rate and longer life when compared to micro-inverters.  Power optimizers isolate each panel from the solar array. However, unlike micro-inverters, power optimizers don’t convert DC power to AC power. To achieve power conversion, a power optimizer is connected to a string inverter, providing the best of string inverter and micro inverter functionality.  Although this can seem like a complicated set up, power optimizers’ true value can be found in their price. When paired with a string inverter, the power optimizer set up is still more affordable than the micro-inverter. Plus, the combo matches the efficiency and safety of micro-inverters.

Micro-Inverters

The popularity of micro-inverters and power optimizers is easily attributed to the many advantages they offer. For example:

  • They offer panel level monitoring
  • They’re weatherproof and can be installed on the system’s frame or rack
  • Simple ‘plug and play’ installation and setup
  • Convert a solar panel’s direct current (DC) into alternating current (AC) at the panel(micro-inverter only)
  • Operate optimally in shady conditions, unlike other inverter types
  • Are safe to handle, even when exposed to the sun
  • A single malfunction doesn’t affect the other solar panels

String or Central Inverters

If you know how solar energy works, you know that solar systems can’t operate without a power inverter, and that the original inverter offering was the ‘string’ inverter. The name is derived from how the system works. The single or central inverter for the solar array has wires or DC panels that are set up in a string and converted to grid AC by that central inverter. These inverters are ideal in areas that won’t have shade.  For this reason they are the best option for ground mounted systems. They are durable and more affordable than other micro-inverters or optimized inverter types. They’re also a ‘tried and true’ technology that solar system owners have trusted for the past 40 years. Not to mention, string inverters are the most popular grid-tied inverter.

Have questions about inverters? Call us for more on this or any other questions you may have with regards to a residential, commercial or agricultural solar energy system.