Off-Grid Inverter – The Ultimate Guide

Choosing a highly efficient and reliable off-grid inverter will guarantee an uninterrupted and steady power supply to your home.

However, this is only possible if you fully understand all the critical aspects of off-grid power inverter. You should know how these power inverters work, their benefits, main components, and output signals, just to mention a few.

For an easier understanding – this guide has everything you are looking for about these power systems.

What is an Off-grid Inverter?

An off-grid power inverter is a special device with interconnected electronic components for transforming direct current (DC) into alternating current (AC), designed for use in an off-grid system.

That is, when using these systems, you don’t connect to the public utility lines or electrical supply. However, you can conveniently use this power inverter with home solar systems or batteries.

At times, you may also refer to this device as an off-grid solar inverter.

Functions of Off-grid Solar Inverter System

These DC power inverter systems perform two critical roles:

Converting DC to AC

Most electronics use alternating current (AC). Remember AC is popular due to easy power transformation, power generation, suitability for distribution, and minimal power loss during transmission.

For this reason, on-grid supply is always in AC. Therefore, converting your DC to AC is critical.

Allows you to Generate Power

An off-grid power inverter will allow you to generate power using either battery or solar panels. Therefore, you can set up an independent power supply system without relying on the on-grid power.

Benefits of Off-grid Power Inverter

There are many reasons why you should consider installing off-grid power inverters such as:

• Provides uninterrupted power– During power outages your best off-grid solar inverter for homes provides an alternative source of power from solar panels or batteries.
• Forms part of green power supply– Solar power is a known source of green energy. By incorporating off-grid power inverter, you will be promoting sustainability in the energy sector.
• Modular design– The modular design guarantees easier maintenance, portability, and effectiveness when deploying the system.
• Remote monitoring capability– remote accessibility allows for easier monitoring and troubleshooting of the system in case of any possible faults.
• Free from increasing energy bills– Since solar inverters will help you generate power, you will be free from any increase or fluctuations in energy bills. Remember, you will not pay for any energy supply from the grid ties system.

But, even as you choose the best off-grid power inverter, there are certain limitations you must consider such as:

• The initial cost may be high as you will need to purchase an off-grid inverter, solar panels, storage batteries and related accessories, but you can make choices based on actual usage
• Both solar panels and battery determine the total power you can get, which may require prudent energy management
• Battery requires constant maintenance for better efficiency

Features of Off-grid Solar Inverter

The best off-grid inverters have features that optimize DC to AC conversion. It will also include other additional features that guarantee safety and reliability.

Let’s look at critical features the best solar inverter for off-grid should have:

Battery Charging and Management Systems

Ideally, this system optimizes the stored energy. The systems achieve this through advanced battery protection, monitoring battery operation state, and optimizing battery performance, among other functionalities.

Voltage Regulation

The off-grid inverter supplies a stable alternating current. With a stable voltage output, there will be no possible fluctuation in all electronic performance.

Remote Monitoring Capability

There are off-grid solar power inverters with remote monitoring capability. This option allows for remote fault detection, and performance status monitoring.

Expandability

A system allows for expansions. Therefore, you can increase your power supply capacity. Of course, this will depend on your energy requirements.

Safety Features

In any electrical system, safety is critical. Therefore, an off-grid inverter must have appropriate safety features such as:

• Overload protection
• Overheating protection with automatic shutdown
• Short circuit protection
• Protection against both under-voltage and over-voltage
• AC back feed protection

All these features ensure the off-grid power inverter operates within safe parameters.

Off-Grid Solar Inverter Working Principle

Whether you are referring to an off-grid solar panel kit with battery and inverter or a design without a battery, the principle is quite straightforward – convert direct current into alternating current.

To understand how off-grid solar inverters, first it is important to mention that the electricity from batteries or solar panels is unidirectional. That is, the electrons move from the source, through the load, and back to the source. It is what we refer to as the direct current.

However, an alternating current is a situation where the electrical energy is bidirectional. That is, it periodically changes the direction of flow. So ideally, the voltage is never constant since it moves from zero to maximum (positive) then back to zero, and to maximum in the opposite direction (negative).

Now, the number of times the voltage transitions from positive to negative is a critical parameter called the frequency. Remember, if you are designing an off-grid solar inverter for regions like the U.S. then it should achieve a 60Hz frequency. However, for other regions globally, it should be 50Hz.

Therefore, your off-grid inverter should achieve this particular scenario – the ability to alternate the direction of current at a desired frequency rate.

The working principle of an off-grid inverter depends on a special switching mechanism. The most common switches in power inverters for off-grid systems are insulated-gate bipolar transistors (IGBTs).

Additionally, it has a controller that helps in opening and closing the IGBTs. Usually, the opening and closing is very fast.

Now, as the DC flows from either the battery or solar into the off-grid inverter circuit, the circuit will open in a manner that alternates the current flow. As a result, you will have an alternating current flow.

To achieve the desired frequency, you must configure the controller system. That is:

• Closing and opening 120 times in a second –  then the output will be 60Hz
• Closing and opening 100 times in a second gives an output of 50Hz

However, this process will not alter the voltage output from the switch. Since you may want to achieve either 120V or 240V from the off-grid power inverter, you need a transformer.

Therefore, a step-up transformer will increase the low voltage to a desired threshold that is useful.

But, the working principle does not end there.

Usually, the output from the transformer is not a smooth waveform. That is, the output will be a square wave (both negative and positive regions). A square waveform is not suitable for sensitive electronics.

By using a pulse width modulator, you can control the power output thereby producing a smooth waveform. The result will produce a smooth sinusoidal waveform electrical signal.

At times the design of these off-grid solar inverter systems may vary slightly depending on the manufacturer. Depending on your design, you can get:

Off-Grid Pure Sine Wave Inverters

A pure sine wave is an expensive option, but versatile and works better for all electrical systems. The off-grid pure sine wave inverters are popular for most home applications. These may include electronic systems, fluorescent lighting systems, fancy electronics, new television models, and inductive loads, just to mention a few.

Even if you need to use higher power loads, you can connect off-grid pure sine wave inverters with parallel capability in parallel for higher power output. For example, two 5kW off-grid Pure Sine Wave inverters can be paralleled for up to 10kW.

Off-grid Modified Sine Wave Inverters

If you are working on less efficient power off-grid systems, then you could opt for modified sine wave inverters.

Generally, they are only suitable for simpler systems and are not expensive in most cases.

Off Grid Square Sine Wave Inverters

They are simple output which is cheap and not very versatile for most applications such as motor systems.

Remember, you can also use the type of power waveform above to classify the various types of solar off-grid inverter systems.

With this information on how off-grid inverter works, let’s have a quick recap about a few aspects:

• The main source of direct current for off-grid power inverters isphotovoltaic solar panels or batteries.
• Off-grid inverter system is the center for voltage conversion
• Depending on the power inverter design, there are multiple operating options and modes

Modes of Operating Off-Grid Power Inverter

Depending on the off-grid inverter design, there are varying modes of operation such as:

Off-grid Mode

In off-grid mode, the power inverter converts the direct current from the solar panels or battery to alternating current.

Battery Backup Mode

During this mode, the off-grid solar inverters use power from the battery and supply it for use. Usually, it switches to the battery mode when the power from the grid is off.

Grid Assisted Mode

When the off-grid solar inverter works alongside the utility grid, then we refer to the mode as grid-assisted. That is, even though it uses solar power as a source of energy, the system can also use power from the main grid whenever necessary.

Comparing Off Grid Vs On Grid Inverter

When it comes to the power inverter industry, you can choose either off-grid or grid-tied inverter. Let’s compare these two power systems:

In short, the main difference between an off-grid inverter and a on grid inverter is whether or not it must be connected to the grid for use, and whether or not it can be connected to batteries.

How Much Best Off Grid Inverter Cost

Usually, the off-grid inverter manufacturers will determine the ultimate price based on the equipment features, specifications, and technology. Additionally, the off-grid power inverter model and brand will also determine the prices.

On average, experts estimate that for a complete solar panel system, the inverter alone can cost about 25% to 30% of the total value of the entire system.

Take for example the price of a 10kVA off-grid solar inverter will not cost the same as a 3000-watt off-grid inverter.

Simply put – once you know your power requirements, simply contact a reliable off-grid inverter manufacturer or supplier for an accurate price quotation. Even if you want to venture into OEM off-grid inverter or distribution, you will get better prices.

How Hybrid Inverter vs Off Grid Inverter Compare

Both off-grid and hybrid inverters are two technologies that have changed the modern power supply industry.

Although a hybrid inverter is costlier than an off-grid solar power inverter, it offers additional sophisticated  functionalities. That is, the hybrid system has an inverter and rectifier as a single unit.

The most important difference between the two is that the hybrid inverter can be fed back to the grid, but the off-grid inverter can’t.

How to Choose Off Grid Power Inverter

When shopping for an off-grid power inverter system for your applications, you should consider the following;

• Calculate your energy needs requirements which helps in off-grid inverter sizing
• Know the solar inverter power rating
• Consider waveform type and frequency
• Types of off-grip power inverters in the market
• Identify where you intend to install the system
• Safety protection features
• Understand the benefits of going off-grid
• Ensure you comply with the regulations and laws
• Understand off-grid inverter installation requirements
• Identify brand and model

Once you consider all these, you will choose the best off-grid solar inverter for your home or office.

Where to Use Off-Grid Inverter

These power systems are a perfect choice for most off-grid applications. That is, they are a perfect choice when you do not want to connect to the main electrical grid supply.

Among the common applications include:

• Cabins
• Boats
• Homes
• Farms
• Ranch
• Small Workshops
• Recreational vehicle
• Standalone storage facilities
• Schools
• Hospitals in remote areas

FAQs

What is the Service Lifespan of Solar Inverters?

On average, off-grid solar power inverters have a lifespan between 10 and 25 years depending on:

• Solar inverter type
• Use
• Installation environment
• Maintenance
• Following recommended instructions
• Brand

Always check the solar inverter warranty period.

Which Certifications Should Solar Invert Comply with?

They may vary depending on the jurisdiction. Some common certifications include IEC 62109-1L458, 62109-2, 61000-6-1, 61000-6-3, 61000-3-11 and 61000-3-12.

Others may include RoHS, CE, CCC, and UL.

How will you know if the Battery Connected to Off-grid Power Inverter is Charging?

Most inverters have LCDs to show whether the batter is charging or not, thanks to technological innovations.

How Can you Connect Off-grip Power Inverters to Batteries?

The process is simple:

• Battery bank voltage should match the off-grid power inverters. These inverters can be designed for 12V, 24V, or 48V.
• Choose a strategic location for your inverter and batterypack. It must be well-ventilated and waterproof areas away from possible flammable materials.
• Mount the off-grid inverter on a stablewall
• As a safety precaution, disconnect other power sources to prevent possible electrocution or possible damage
• Identify the positive (+) and negative (-) terminals on the battery and power inverts. Then fix the connections. They must be secure and tight.