Grid-tie inverter that does not feed into the grid


This is a new addition to the grid-tie inverter. First, let me explain the system very well! If you have a hybrid inverter with off-grid capability, you can successfully switch the system. But, the question is how?

Here’s come a small twist. Before you move on, you need to disconnect the grid side when the power goes off. Then, simply put the system on off-grid mode and operate. However, you will still need batteries; otherwise, the inverter would shut down. If you find the PV output cannot satisfy the power load, you have to install batteries.

Now, to understand the entire mechanism clearly, you have to learn an entirely new chapter. What is it? It is the system of Grid-tied, off-grid, and Hybrid solar inverters.

Grid-tied inverter systems

A grid-tied or on-grid solar system is directly connected to the utility power grid. Hence it’s called ‘grid-tied! Fortunately, this system offers a higher efficiency rate. Moreover, its lower equipment and installation charge enables optimum benefits for the users.

grid-tied-solar-system.png

If you are looking for a cost-saving option grid-tied system is an ideal choice. Henceforth, many homeowners install this inverter system for better utility. On the other hand, net metering plays a crucial role here. Apart from that, a residential solar system is a feasible option.

Equipment needed for the GTI system

Using two basic equipment, you can install the system.

  • Grid-tie inverter
  • Power meter

Off-grid system

As the name suggests, it is a standalone infrastructure. Moreover, once you have access to the grid, the question of off-grid never comes to mind.

off-grid-solar-system.png

In addition, to ensure the supply of electricity, this system requires a backup. Of course, battery storage takes control if anything goes off. However, this battery bank needs to be replaced at least after ten years of interval.

Interestingly, off-grid refers to self-sufficiency. Most importantly, it is cheaper. On the downside, the supply of a battery bank might pose an issue here. Unfortunately, consistent cloudy weather can be another challenge for the owners. In that case, they need to install an additional generator to continue the power supply.

Equipment needed for the off-grid system

  • Solar charge controller
  • Additional DC connector
  • Off-grid inverter
  • Optional back-up generator
  • Battery bank

In this case, a potential charge controller is fundamental. On the other hand, based on the regional setup, owners also need additional backups.

Hybrid system

It combines both grid-tied and off-grid mechanisms. However, this system is quite complicated compared to the other two. Fortunately, it is much cheaper than the installation of an off-grid system.

hybrid-solar-system.png

As a smart inverter technology, it offers various promises. Hence, it still has room for innovation. Consequently, the owners can temporarily store the excess electricity in the batteries. Then they can also put it on through the utility grid.

Equipment needed for hybrid system

  • Charge controller
  • Sustainable battery bank
  • Additional DC connector
  • Battery-based grid-tie
  • Robust power meter

Understanding grid-tie inverter

So, a grid-tie inverter converts DC or Direct Current into AC or Alternating Current. Hence, it prepares the system to inject the electrical power grid. Usually, the voltage ranges within 120 V. 

However, the inverter should match the voltage to infiltrate the electrical power securely to the grid. Moreover, with net metering, the excess power would be recorded.

Operation

Now, let me discuss the operational mechanism of the grid-tie inverter:

  • An efficient grid-tie inverter can generate lined up voltage. Hence, it matches with the higher parameter of the AC power grid.
  • It also has an onboard computation system. Interestingly, this automated system can analyse the AC grid waveform and the output voltage.
  • In addition, it also can disconnect the grid when the utility goes down. In fact, it is an NEC requirement to ensure any blackout. Hence the inverter gets shut down to prevent energy transition.
  • Moreover, the configuration enables the owners to use the alternative power system. However, if the energy source is not sufficient, it automatically consumes the power from the electricity grid.
  • Its conventional and low-frequency type is suitable for AC and DC suitable grid. In addition, the transformer uses an automated computing process to convert high frequency into Direct Current. Then, it is converted to Alternative Current output.

Grid-tie inverter that does not feed into the grid

This process is often practised. However, it is still not widespread. If you follow the following process to enable the GTI, that doesn’t feed into the grid.

Finally, the inverter power generation capacity must the large enough to produce the capacity of a Grid-tied inverter. Then, the grid-tie inverters are connected through a switch and allow a safe disconnection. To monitor or protect the circuit, a relay can be used.

However, you need to make there are adequate loads to absorb the power. Typically, it should be large enough to absorb the power from the GTI. Once it is fully charged (90%), you can disconnect the protection relay.

Can I use a grid-tie inverter without Netmeter?

If you have ZED Advance available, you might not need net metering. Moreover, you don’t need any approval from the state electricity grid with a Grid-tie inverter. Hence, commissioning a net Metering is possible with ZED Advance.

Can you trick a grid-tie inverter?

You can trick a grid-tie inverter with an off-grid system. The off-grid system is a tricky method that needs a 600-volt string inverter. If you can add battery backup to an existing grid-tied, it can automatically turn on the power of the critical appliances.

Can a hybrid inverter work without a grid?

An off-grid inverter can work with an off-grid solar system as it needs enough space to store energy for at least two days. Similarly, hybrid system inverters use hybrid grid connectors. The battery needs to be large enough to supply 5 to 10 hours of energy based on the application.

Can we connect the grid-tie inverter directly to the off-grid system and use it without connecting it to the grid?

YES, YOU CAN. However, you have to modify the control system of the inverter. Hence, it will help the control system to switch between grid operations and standalone operations.

Matt

I’m Matt, a computer and electronic embedded system developer. Currently, working as an electronic engineer. In my leisure time, I do love to blog about technology stuff. Specially, new advance high tech devices. Portable solar systems are one of topic that I love to investigate. They are becoming more powerful day by day which keep me alert.

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