A string inverter is a single, standalone unit that converts power from a whole string (or strings) of solar panels. String inverters are cheap and convenient, but tend to be the least efficient in situations where there is shading issues on the roof.
String inverter + power optimizer: Power optimizers are attached to each individual panel. They perform MPP tracking at the module level; the optimized DC power is then sent to the string inverter for conversion into AC power. Combining string inverters with power optimizers will increase your cost but allow your system to handle issues like shading better.
Advantages of installing a string inverter
One of the main advantages of a string inverter is that you only need one of them to convert the DC electricity coming from your solar array to AC power. If anything is going to fail in a solar system, it is likely to be the inverter – making troubleshooting relatively easy when things go wrong. Installing a single string inverter on a solar panel installation is cheaper than installing microinverters. Less labor hours are required, and string inverters are more affordable than many microinverters.
Microinverters are another type of solar inverters. Microinverters are attached to individual solar panels. They perform both MPP tracking and power conversion at the module level, allowing each panel to output usable AC power. They’re especially beneficial in situations when there is shade from trees, etc and have the additional advantage of making your solar system easy to expand. They are, however, the most expensive type of inverter.
Advantages of installing a microinverter
- Rapid shutdown capability
New electrical codes require rapid solar system shutdown so first responders or firefighters are safe from high voltage when they need to be on rooftops or servicing power lines. Microinverters comply with these rapid shutdown requirements and have this capability embedded into each module.
- More electricity
The core advantage of using microinverters is that theoretically, you can yield more solar electricity. The reason for this is that there are slight differences in currents between solar panels. When solar panels are in a string, the current is reduced to that of the least-producing panel in the string.
- Suitability for challenging installation conditions
If a solar system is facing multiple angles, meaning some panels are facing south, some east, and some west, then microinverters are the way to go. Or, if you have shading issues from trees or a large chimney, again microinverters help combat issues that come with shading by helping your solar panels produce optimal power.
In these situations, the solar panels will be producing different amounts of electricity at different times of the day, but microinverters will ensure you harvest all of the energy, while with a standard inverter you will lose some of this solar production.
Microinverters typically have 25-year warranties while standard string inverters typically have a 10 year warranty. Microinverters and the add-on optimizers have the ability to track the production of each individual solar panel, while with a string solar inverter you only can track the production of the whole system. Microinverters are definitely a value-add, but are only recommended if you need to comply with rapid shutdown requirements, have panels facing multiple orientations or you have shading issues. Otherwise, the less-expensive standard string solar inverter is usually more cost-effective.
Contact Austra Solar today for a free quote on a solar power system and let our solar experts help guide you on the right type of inverter for your home or business.