How Does A Grid-Tied Inverter Work?

Energy demand is directly proportional to the population. No, we are not solving any expressions in this blog, but we might give you an idea of how you can use renewable energy to make resourceful use of your land. 

Fossil fuels have been a significant source of energy and income. However, they are also significant producers of harmful greenhouse gases, responsible for climate fluctuations and natural disasters. The increased demand for energy is presently being balanced and fulfilled by renewable resources.

Renewable resources of energy include solar, wind, hydroelectric, or biomass. Recent developments in technology and successful development in harnessing renewable energy have made it a more reliable option.

Solar energy wins the position when it comes to easily accessible and reliable renewable options. 

Solar energy plays a significant role in the green revolution. On the other hand, solar farms increase property value and benefit the economy by creating jobs in the green energy sector.

Solar panels installed in houses or solar farms need grid-tied systems or inverters to convert sun rays into electricity. In this article we’ll see how grid tied inverters work.

What is a Grid-tied Inverter?

Solar panel systems are most common in American homes. There are different technologies to harness solar energy.

A grid-tied inverter (GTI) is an electronic device that converts direct current to alternating current. Solar energy is abundant and can be used efficiently with improved technology. 

A grid-tied system is one solar power equipment that works without battery backup. However, the off-grid system is quite different where electric power can be stored in batteries.

The growing interest in solar panels and renewable energy is a good sign. The advancement of technology has helped people to harness solar energy easily. A grid-tied inverter is an essential element for converting electricity from direct current to standard one.

Grid-tied inverters are used for solar panels, hydroelectric, and wind turbines. Grid-tied inverters are power efficient and accurate to match the voltage. GTI’s are suitable for converting current for power grid frequency from 60 Hz-50Hz, commonly used for local electrical generators.

How do Grid-Tied Inverters Work?

Fossil fuels damage the environment with weapons like global warming and greenhouse effects. The increased demand for energy sources has significantly expanded the reliability of renewable resources.

This demand supply can be balanced only by a strong distribution channel and advanced electronics technique. Continuous research and the conceptual frame have developed reliable PV grid-tied systems or inverters. 

Grid-tied inverters are reliable, and table solar panels have photovoltaic modules. When sun rays fall on this panel, a direct current is generated through the photovoltaic process. This direct current or DC flows to a grid-tied inverter, converting it into alternating current or AC.

This AC power or standard electrical current is transferred to the home’s electrical service panel to power appliances.

Additionally, you can install an optional tracking meter or check online the production and consumption of energy. This whole concept of the grid-tied system is functional only in the presence of an electric grid.

The output voltage and current are lined up and fixed in a modern grid-tied inverter. As per the National Electrical Code (NEC) or National Fire Protection (NFPA 70) rules, the United States prioritizes safe electrical practices.

According to this, GTI’s are designed so that if the utility grid goes down, it gets quickly disconnected from the grid, and this process prevents any harm to line workers.

Grid tied inverter Circuit

It’s very important to know the circuit of a grid-tied inverter to know about the working principle.

In the above circuit, there are many components like capacitors, inductors, diodes, MOSFETs, and transformers. Capacitors are denoted as C, inductors are denoted as L, diodes are denoted as D, transformers are denoted as T, and MOSFETs are denoted as Q.

Working Principle

The whole job is being done in a three-step conversion. The DC input is converted to 60 Hz AC in the first stage. Then a low-frequency step-up transformer converts it to the required level in the second stage conversion. In the third stage, another DC-AC conversion takes place that converts the remaining part of AC into the output of the second stage.

The input voltage is first raised by the boost converter formed with L1, Q1, D1, and C2. If a PV array is rated for more than 50 V, one of the input direct current buses needs to be grounded (usually the negative one). The transformer is used as a DC-DC converter. The above schematic diagram shows one “full-bridge converter.” It comprises Q2-5, T1, D2-5, L2, and C3. T1 is a step-up transformer. You may not need a “full bridge” if you use a power level below 1000 watts. Then only a half-bridge converter will do the job well (in both first and third stage conversion). The third stage converter consists of Q6-9 and LC filter consisting of L3 and C4.

Connection to the grid

In the case of a grid-tied system, you just have to know that the power source/inverter has to synchronize its frequency, amplitude, and phase with the utility and feed a sinusoidal current to the load. If it doesn’t, it might be problematic whether the output is higher or lower than the grid. The higher output will overload the grid. In the lower output, the grid will work as a sink rather than acting as a source. So, usually, there is another coupling inductor (L-grid) between the system and the grid to absorb the extra AC voltage.

What Happens on a Bright Sunny Day?

Grid-Tied inverters are designed as an interconnected link to your home and also the main power. Recent advancement and the use of artificial intelligence ensures various benefits.

AI helps to synchronize power production and its timely delivery. Even after constant variation in sunlight’s frequency, the system ensures power supply to the main panel.

Mostly, the energy consumption is low during the day, and energy production by the solar panel is at its peak. Excess power is exported to the utility grid and can be used whenever needed. Also, this saves a lot on electric bills.

Components You Will Need to Install Grid-tied Inverter

Grid-tied inverters are easy to install, stable, and efficient. They require minimum equipment and average maintenance to function. However, there are few onsite equipment and wiring you will need.

1. Solar Panels: Modules to capture and generate DC power.
2. Wiring: Proper wiring with connections to the main electric panel and net meter.
3. Net Meter: It works as a tracking system and monitors power exchange between the home and the main utility grid. 
4. Isolator: In case of any malfunction or failure, isolation helps to separate supply from the grid to prevent any major shutdown.
5. Protection unit: Although inverters have inbuilt protection units, this helps with extra security in case of any faults or overload.

The solar panels and inverters are the kit’s main components and are necessary for roof-mounted installation as it requires more effort.

Benefits of Using Grid-tied Inverters

Grid-tied inverters are bidirectional, which means they supply AC power to house electricity panels and export excess power to the utility grid.

However, you need not worry about records because net metering records input, export, and the earning at the end of the billing cycle.

Following are some benefits of using grid-tied inverters:

• GTI comes with easy installation and cost-effectiveness.
• With grid-tied inverters, you can be stress-free about the amount of load on the connection.
• It is a more efficient and stable option with no requirement for batteries.
• This system offers minimum maintenance cost and pocket-friendly equipment.
• GTI is easy to install and helps in reducing electric bills.
• It provides better efficiency rates with the support of net metering.
• According to some studies, GTI’s are capable of generating more power.
• Grid-connected solar systems are affordable and increase the value of your property.
• The best part is that you get to use one hundred percent renewable energy, which positively impacts the environment.
• With the easy transformation of electricity, GTI is resourceful.

Check out the best grid-tied inverters here!

How long-lasting are Grid-Tied Inverters?

An unlimited supply of clean energy with grid-tied solar energy systems can be known for their techno-driven and bidirectional features. Inverters are an essential part of the whole system, and daily production and consumption of power can differ according to weather and usage.

However, if excess power production occurs, the inverter will send it to the utility grid. Also, GTI works by pulling the extra power from the main utility to meet the power production needs is less than required.

GTI also works as a guard to protect from short circuits and overloads. Due to constant bidirectional supply, solar inverters need to be safe and secure for use. Solar inverters come with a lifespan of around 10 years.

Solar PV’s live for approximately 25 years; however, GTI’s can last for more than 10 years with regular maintenance and repair for smooth functioning. 

Also, 2%-7% of power is required to run the inverter. So, if the efficiency of the inverter is 93%, it means the inverter consumes 7% power for functioning.

Factors affecting the lifespan of GTI are excessive temperatures, positioning, inferior quality of inverters, and fluctuating voltages.

How to Choose and Maintain Grid-Tied inverters

Research, plan, ask, and install. You can do a little research according to your planned budget and always include replacement terms and conditions and warranty provided by the company. You can also consult someone who owns a functioning solar power setup.

After you’re done with the installation, make sure to follow safety instructions, cleanliness and prevent it from overheating by ensuring proper wire support and grid functioning.

Other Types of Grid-tied Inverter 

As the distribution channels attain importance, renewable resources successfully deliver power. So, when you decide on solar second important is solar inverter; the first is panels, of course. Here goes the list you can check:

1. String Inverters: They are the most common type of solar inverter, wired together in series, and each string between them functions by converting DC power into AC.

They are the oldest form of solar inverters, reliable, and least expensive. It works out as a suitable option for commercial and small households which require a typically low solar budget. Also, if a single panel gets under shadow or gets damaged, it affects the entire system’s performance.

2. Central Inverter: This type resembles the working of string inverter but offers a high capacity range. It is suitable for large utility consumption applicants and perfect for large commercial plants. The central inverter is comparatively resistant to environmental damage and worthy for large solar farms. 

3. Power Optimizer: It is attached at the back of each solar panel. Individual solar panels produce DC power. Also, this system does not degrade the entire setup if any solar panel is partially shaded. They have panels as well as a system-level monitoring system. As it can be installed only on the roof, repair and replacement are tricky.

4. Micrometer: This comes with the latest technology and functions by converting DC power to AC power directly from the back of each solar panel. They do not have strings interconnected, which results in a minimum effect of shading to power output.

This is a perfect solution where space is an issue. It is costly but protects from any damage or variation in output due to shade. It can be extended as per requirements and offers an individual monitoring system.

Is Grid-tied the Best Option?

GTI saves you extra by channelizing extra power to the main grid. But is GTI the best option, or is there anything better available?

Renewable resources are available worldwide, and it requires proper techniques to harness the energy and convert it to a usable form. Any energy consumption can sustain globally; however, renewable resources depend on geographical conditions, weather variation, financial reliability, and source efficiency.

GTI reflects as an investment and is a good option for businesses, homes, and solar farms. It comes with quality like easy replacement, maintenance and is less expensive. Although factors like condition, requirement, and budget always win the race!

Cost Calculation of Grid-Tied Inverters

GTI offers an uninterrupted power supply. On average, systems cost between $ 2.85 per watt as of 2021.

Considering other factors and variations in the quality of panels and solar systems, you can find the price. Also, there are various advanced online solar calculators available, and they help with the company, warranty, budget, and locality.

Difference Between Grid-tied and Off-grid System

The increased percentage of carbon emission has successfully grabbed our attention towards alternative energy sources. Renewable energy is a promising and inexhaustible resource to meet energy requirements. 

Off-grid inverters need batteries that make them more expensive, and this makes the grid-tied more environment friendly and less expensive.

Off-grid is a popular choice in remote areas, and it offers complete independence from the power company. Owners might face a surprise power cut due to any malfunction in batteries.

On the other hand, on-grid inverters are suitable in areas with proximity to the utility grid. Budget-friendly, easily add or remove panels according to requirement.

Cons of Grid-tied Inverters

• Electricity can not be stored, and you can’t access the battery bank. However, you can use a battery to store if you want to increase the cost slightly.
• Due to safety concerns, it will not function during electronic blackouts.
• Solar energy production dominantly depends on the area covered by solar panels. 
• The initial investment can be high.

Conclusion

Increasing demand for power sources is focusing the shift to alternative energy sources. Also, the slow yet significant change in weather and extinction of flora and fauna is enough to tell us something is wrong.

Choosing renewable energy and daily life can benefit the environment and secure the future. Solar energy is a free potential source with an uninterrupted supply, and the mid-1990s happened to be a milestone for solar PV. As per the reports of IEA, demand for renewable energy increased 3% in 2020.

However, the expansion of renewable energy reached more than 8%. Total solar electricity generation of the US increased from 5 million kWh in 1984 to 133 billion kWh in 2020. The United States is the second-largest solar electricity producer in the world.

Technology and innovation benefit the renewable concept of living. Also, it is a reliable and safe way for the environment too. With solar, you have the power to generate, store and use electricity. Plan your budget and finalize your requirements, and you’re good to go solar!