Solar Micro-inverter 101

Micro-inverter can be said to be a branch of solar inverter, or to be very different from solar inverter. If you are hesitating whether to purchase a micro-inverter for home/commercial PV panels, this guide will effectively help you acquire the introductory knowledge of micro-inverter, and you can grasp the direction without complicated thinking.

What is micro-inverter?

Solar micro-inverter is an inverter designed to connect?with a single PV module. It?is a device that directly converts the DC generated by each module into AC and then connects to the grid.

The main advantage of micro-inverter?is that each module?can be independently controlled by MPPT?function(Maximum Power Point Tracking), which will greatly improve the overall production efficiency.

How does micro-inverter work?

Inverter plays an important conversion role in the solar system, it needs to convert the DC generated by the solar system to AC used by home. Generally speaking, string?inverter can connect PV?panels in series and parallel to form a PV?array, then convert?DC into AC and connected to the grid.

Micro-inverter also convert DC to AC, but the difference is that a micro-inverter is installed after each PV module, and the module-level conversion efficiency is much higher than that of conventional inverters.

Micro-inverter product type

Single-in/Dual-in/Quad-in/Sexa-in

1-in-1 means one micro-inverter connects one solar panel, 2-in-1 means one micro-inverter connects 2 solar panels, 4-in-1 means one micro-inverter connects 4 solar panels, and so on. The x-in-1 is a very powerful technology that can simplify installation steps and reduce installation costs for complex rooftop PV systems.

Why choose micro-inverter? (compared to string inverter)

• Independent MPPT control which greatly increase power generation;
• Full AC design to avoid the danger caused by DC high voltage;
• Good expansion, the system can be freely expanded by monolithic cells;
• Module-level monitoring;
• No single point of failure;
• Lifespans up to 25 years;
• Easy to install;
• Enclosure rating IP67;
• Highest safety

Why not choose micro-inverter? (compared to string inverter)

• Compared with string inverters, the cost per watt of micro-inverter is higher. The micro-inverter is installed behind each PV panel separately, which can realize panel-level monitoring, but the quantity required is large, and the price of a single product is relatively high.
• Large number of installations and high maintenance costs. Micro-inverter usually requires a number of installations which cause the high cost. After the fault occurs, it is difficult to detect the specific fault location in many micro-inverters, and the maintenance cost is high.

What need to know before buying a micro-inverter?

Cost

Cost is a factor to consider before purchasing PV system supporting facilities. Micro-inverters, in particular, have a higher cost per watt than conventional inverters. Buyers need to fully consider the budget to purchase the products.

But in fact, in distributed PV systems such as residential scenarios, after considering the higher total system efficiency, calculating LCOE (kWh cost) or IRR (return on investment ratio) has more advantages than string inverter systems. And in recent years, the cost of micro-inverter has decreased significantly.

Specifications

There are many types of micro-inverters on the market, and their main specifications should be fully considered before purchasing: rated power, peak power, peak efficiency, CEC/EURO efficiency, maximum short-circuit current, maximum continuous current and communication.

MPPT

Maximum Power Point Tracking (MPPT) is a technique used with variable power supplies to maximize energy extraction as conditions change. This technology is most commonly used in PV systems. The core problem addressed by MPPT is that the power transfer efficiency of a solar cell depends on the amount of sunlight available, shade, solar panel temperature and electrical characteristics of the load.

Warranty

The power of a single micro-inverter is 250w-1000w. It uses?the glue filling process and has an IP67?enclosure rating. It is estimated that the electrical parameters of the micro-inverter?are basically stable within the ambient temperature range of -40℃ to 65℃. The service life of the micro-inverter is 2-3 times that of the string inverter, which?is up to?25 years?and consistent with?the PV modules, and is complied?with the design and use of PV systems.

Who are the current excellent micro-inverter manufacturers?

BENY

Headquartered in China, BENY?Electric has offices in the Americas and Europe. It is a globally trusted manufacturer of PV?system protection components. BENY?has more than 30 years of experience in the PV?industry, and the R&D team is able to manufacture solar modules that meet the latest DC standards.

BENY micro-inverters offer many advantages such as rapid shutdown, flexibility in panel layout, and module-level monitoring and diagnostics. BENY Electric also independently developed a PV parallel optimizer for the characteristics of micro-inverter products. It has the characteristics of ultra-low drop and ultra-low loss, which can solve the problem of current backflow reducing the life of photovoltaic modules or damage to parallel photovoltaic modules, and can improve the performance of parallel PV modules MPPT efficiency.

ENPHASE

ENPHASE is an American energy technology company headquartered in the United States that develops and manufactures solar microinverters, battery energy storage and electric vehicle charging stations. ENPHASE is the first company to bring micro-inverter to the market and implement commercialization.

ENPHASE's IQ series micro-inverters use a simplified wiring system, and the latest IQ8 series can achieve backup during grid interruptions. ENPHASE micro-inverter product series is divided into residential?and commercial use, independent research and development of monitoring equipment and monitoring system, and use together with the supporting energy storage system.

APsystems

Headquartered in China, APsystems focuses on the R&D of module-level power electronic. Its products include micro-inverters, power optimizers, EMA intelligent monitoring and operation platforms.

APsystems has developed the earliest three-phase micro-inverter optimizer. Dual-in and quad-in micro-inverters for residential use, and three-phase for commercial use, supporting monitoring equipment and monitoring system to realize intelligent micro-inverter operation system.

Conclusion

Micro-inverter utilization rate in residential small PV systems has gradually increased, and it is a strong competitor of string inverters. The small size and high-efficiency design of the micro-inverter can well solve the decline in PV production capacity caused by the shadowing problem of some panels.

In summary, if you have fully understood the specifications of the PV system used and your own needs, contact BENY now to obtain the industry's highest performance micro-inverter product details, and we will provide you with a free customized quotation.