Introduction to grid-tied inverter

With the development of science and technology and the enhancement of people’s environmental awareness, more and more people want to equip their homes with a solar power generation system. In places where power outages occur frequently, solar power generation systems are a good backup power supply solution. Solar inverters are an integral part of the entire solar system. Read on to learn what a grid-tied inverter is and its role in a solar system.

What is a grid-tied solar system?

Also known as grid-connected solar systems or grid-connected photovoltaic systems. Solar panels convert sunlight into direct current, and then the inverter converts the direct current into alternating current for home use. Grid-tied inverters can feed excess power from the solar system back to the grid.

Typically a grid-connected solar system consists of the following main components:

• Solar panels
• Solar grid-connected inverter
• electricity meter
• Grid transfer switch (or transfer switch or interface device)
• wiring
• AC circuit breaker
• Brackets and mounting hardware

The alternating current generated by the solar panels is converted by the hybrid inverter into the same alternating current as the public grid and then sent to the grid through wiring.

The electric company calculates your dues based on the meter reading.

What is a grid-tied inverter?

The grid-tied inverter acts like a middleman, converting the DC power generated by the solar panels into AC power, which can both power the load and deliver power to the public grid.

Types of grid-connected solar inverters

Grid-tied string inverter

Multiple solar panels are connected together in series and then connected to a high-power inverter. The advantage of this is lower cost and installation complexity, but the disadvantage is that if a single panel fails or is shaded, it may affect the performance of all panels connected on the same string.

String inverter with power optimizer

A power optimizer is installed between each battery panel and the central inverter to optimize the power of each battery panel and reduce energy loss caused by performance changes between battery panels, shadow occlusion and other factors.

Grid-connected microinverter

Mounted directly on the back of the solar panel, it enables more precise monitoring and adjustment of the panel’s performance.
When part of the system fails, the microinverter can ensure that the remaining parts continue to operate normally.

A string inverter has multiple solar panels connected, called a string. When combined with a power optimizer, the system becomes more efficient and expensive. Grid-tied microinverters connect to the array at the panel level and are the most expensive of the three types.

How does a grid-tied inverter work?

Solar panels generate direct current after receiving sunlight. The job of the grid-tied inverter is to convert this DC power into AC power. The difference between a grid-connected inverter and an ordinary inverter is that they can transmit excess power to the grid in exchange for a certain amount of revenue.

When there’s enough sunlight, solar panels can produce far more electricity than a home needs. In order to prevent excess power from being wasted, the grid-connected inverter sends this power into the public grid in exchange for income.

At night or during cloudy weather, when your solar panels are not producing enough power to meet your home’s needs, you will draw power from the grid as usual.

Battery-less grid-tied inverter

Grid-tied solar inverters typically operate without batteries and supply power directly to the grid. During a power outage, without battery backup, these inverters will automatically shut down to prevent any power from flowing back into the grid, which could otherwise be dangerous to power workers.

Just a reminder: a grid-tied inverter without battery storage will not work during a power outage. Therefore, most grid-connected inverters today are powered with batteries.

grid-tied inverter and battery work together

Some grid-tied solar inverters come with battery backup, which means they can store the electricity produced by the solar panels. This is especially helpful during power outages, when the grid is shut down but the solar panels are still working.

Solar grid-tied inverter with MPPT control

The main function of the MPPT controller is to continuously track the maximum power point of the solar panel to obtain the maximum electrical energy under any given environmental conditions.

The power output of a solar panel is determined by the product of its voltage and current. However, these two parameters will be affected by environmental conditions (such as temperature, light intensity, etc.) and change at any time. Therefore, the maximum power point of the battery panel is not fixed and needs to be tracked in real time through a method. This is what the MPPT controller does.

The working principle of the MPPT controller is: under a given input voltage and current, through a certain algorithm, the operating voltage of the battery panel is adjusted so that the product of voltage and current reaches the maximum, thereby obtaining the maximum power output.

conclusion

Grid-tie solar inverters are becoming more and more popular as more and more people look for ways to reduce their electricity bills. These inverters allow you to sell excess electricity to the grid, offsetting your electricity bill. Grid-tied inverters come in many sizes and with many functions. When considering investing in this type of inverter, choose one with the features you need.