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Do You Need An Inverter For Solar Panels?

The large panels mounted on the roof come to mind when people think about solar electricity. However, the massive panels are not the only thing you will have to convert the sun’s energy into power. To harness the sun’s energy to run your appliances, they must pass through the solar panel inverter, a vital system part. For a solar system to work, an inverter must convert the energy absorbed by the panels into a safe current.

Since home appliances cannot consume electricity from your battery storage without converting it to AC, an inverter is a must-have for a solar panel. Inverters are required for any solar panel system to function correctly because batteries and solar panels require DC. Inverters for solar panels serve as a backup for your system and also ensure safety as they will turn off if it detects a problem with the electricity. This safeguards your home in the event of electrical failures or other issues

If you want to discuss which solar inverter is right for you, Contact Us or Get a Free Quote.

do you need an inverter for solar panels in nz

How do Solar Inverters Work?

A solar inverter converts your solar panels variable direct current (‘DC’) output into alternate 120V/240V current (‘AC’). Since your home devices run on AC instead of DC, your solar panels DC output should be converted by the solar inverter.

Solar panels or photovoltaic (PV) cells, are composed of silicon cells or aluminium gallium semiconductor layers, and the sun shines on them. The layers are made up of a junction that connects negative and positive layers.

The semiconductor layers absorb light from the sun and deliver it to the PV cell. This energy bounces electrons around, causing a direct current between the negative and positive layers (DC). After being generated, this energy is either kept in the battery for future use or delivered immediately to a working inverter. 

The power to the inverter is given in DC format; however, your home requires AC. The inverter captures the energy and sends it via a transformer, which generates an AC output. In essence, the inverter ‘tricks’ the transformer into believing the DC is true AC by forcing it to behave like AC – the DC is sent through two or more transistors that turn on and off incredibly quickly, supplying two distinct sides of the transformer.

Types of Solar Inverters

Inverters come in different types, and they are all over the market; here, we shall look at different types of solar inverters.

What are String Inverters?

String inverters, also known as central inverters, are the most popular and oldest type of solar inverter now in use. They operate by connecting a series of solar panels to a single inverter, transforming the whole DC input into AC output.

Advantages of String Inverters

String inverters are the most reliable and oldest type of solar inverter, and they have worked out most of the problems after decades on the market. 

 They are also the most affordable alternative for solar inverters.

String inverters can also be mounted on the side of your house or near the side of a ground-mount solar system. This makes monitoring, repairing, and replacing the inverter much easier.

What are solar power optimisers?

Each solar panel has a power optimiser on the back that converts DC to AC with the help of a string inverter. This is accomplished by conditioning the DC electricity generated by each panel and passing it to the string inverter to be converted to AC electricity.

Since power optimisers may condition the DC electricity generated by each solar panel, they can reduce the effect of shading on those panels. As opposed to a simple string inverter configuration, if one solar panel is partially shaded, the output of the entire string will not suffer. 

Advantages of Solar Power Optimisers

Power optimisers enable both panel-level and system-level monitoring.

Since each solar panel is monitored individually, any problems with solar production can be identified more quickly. 

The homeowner can also observe a more detailed level of surveillance.

What are Hybrid Solar Inverters?

This is a multi-mode inverter that requires installing batteries in addition and setup. The inverter supplies DC power to the storm and AC electricity to the grid and your household appliances. 

It can track the amount of charge your battery needs and when it’s time to draw the head from the grid at a reasonable cost because it’s equipped with MPPT.

Advantages of Hybrid Inverters

This charge controller can send extra power back to the grid once the battery has been fully charged. 

Instead of turning off fully, this inverter can be switched to standby mode if a problem occurs.


Micro-inverters are the most recent advancement in solar inverter technology, converting DC to AC directly from the back of each solar panel. Because each micro-inverter does DC conversion on the fly, there is no need for a string inverter.

Since each micro-inverter is responsible for the DC to AC conversion on each panel, shading on individual panels has a negligible impact on the system. In a string inverter design, if shade covers one panel, only that panel will generate decreased power output rather than the entire system.

Advantages of Micro-inverters

Micro-inverters are also simple to integrate into a solar system in the future. A micro-inverter should be mounted on the back of any solar panel added to the system.

Micro-inverters, like power optimisers, enable panel-level monitoring of the solar system, making it easier and more accurate to diagnose any solar output difficulties.

Factors to Consider When Choosing a Solar Inverter

Stability of Output Voltage

Solar cells create electricity held in storage batteries before being converted to 220V or 380V AC by solar inverters in photovoltaic systems. The output voltage of storage batteries, on the other hand, is determined by the charge and discharge of storage batteries themselves. 

Storage batteries with a nominal voltage of 12V, for example, can have voltages ranging from 10.8V to 14.4V. (beyond this range, storage batteries may be damaged). Whenever the input power varies within this range, the change in steady-state output voltage for a certified solar inverter must not exceed 5% of the rated value. 

Meanwhile, the voltage output variance should not surpass 10percent of the rated value when the load changes unexpectedly.

Rated output frequency

Since their ideal frequency is 50Hz, loads with motors, such as washing machines and refrigerators, will heat up and degrade system efficiency and service life. As a result, the output current of solar inverters should be a  steady number, typically 50Hz, with a fluctuation of less than 1% under normal operating conditions.

Waveform Distortion of Output Voltage

The maximum waveform deformation (or harmonic content) should be set for sine wave inverters. The output voltage’s total waveform distortion is one way to express it, which should not exceed 5%. (10 percent is allowed for single-phase output). 

Since inverters’ high-order harmonic output current will generate eddy current and other additional losses on the inductive load, excessive waveform deformation of inverters will cause severe heating to load components, which is not amenable to the safety of equipment and impacts the operational effectiveness of the process.

Load Power Factor

Sine wave inverters have a load power factor of 0.7 to 0.9, with a rated value of 0.9, and can handle inductive and capacitive loads. Whenever the load power is constant, and the active management of the inverter is low, the power inverter’s required capacity grows. 

On the one hand, the cost will rise. When the perceived power of the photovoltaic system’s AC circuit increases, the loop current increases, lowering the system’s loss and efficiency.

What is Electronic Noise?

In power and electronic devices, noise is produced by transformers, filters, inductors, electromagnetic switches, and fans. Solar inverters should not make more than 80 decibels of noise in regular operation, while small-scale inverters should not make more than 65 decibels.

Rated Output Current (Or Rated Output Capacity)

The rated output current of a solar inverter is defined as the rated output electricity within the given load power factor range. Specific solar inverters’ rated output capacity is measured in VA or KVA. 

When the output power factor is 1, the product of the rated output volts and the rated output current is referred to as the inverter’s rated generating capacity (i.e., the pure resistance load).

Solar Inverter Efficiency

The efficiency of a solar inverter is defined as the percentage of output power to input power under specific operating conditions. In general, the nominal effectiveness of photovoltaic inverters refers to the efficiency below 80% of pure resistance load. 

Since the overall cost of a photovoltaic system is quite expensive, it is vital to increase the efficiency of photovoltaic solar inverters, lower the system’s price, and improve the photovoltaic system’s cost performance. 

Mainstream inverters have a notional efficiency of 80 to 95 percent. The efficiency of low-power inverters is above 85%. Not only should high-efficiency inverters be selected in the actual construction of a photovoltaic system, but the load of the photovoltaic system should also operate at near-optimal efficiency through the system’s logical arrangement.

Protection Measures

An excellent solar inverter must also have comprehensive protective functions or procedures to deal with various strange scenarios during actual operation, ensuring that the inverter and other system components are not destroyed.

Input Over-Voltage Protection 

The solar inverter should be safeguarded and displayed with a prompt if the input voltages exceed 130 percent.

Input Under-Voltage Protection

The inverter should be protected, and a prompt should be displayed when the input voltages are less than 85% of the rated volts.

Over-Current Protection

Inverter overcurrent protection should provide timely functioning when a short-circuit develops or the current surpasses the permitted value to avoid surge destruction. The converter should be able to automatically safeguard itself if the working current exceeds 150 percent of the rated value.

Over-Temperature Protection

Furthermore, inverters without voltage stabilising features should incorporate over-voltage output protection to safeguard the load from damage.

Solar Inverter Warranty

Most string inverter technologies have a 10-12-year warranty. However, module-level power electronics (such as micro-inverters and power optimisers) have a 25-year warranty. The warranty terms for the string inverter and the power optimiser are often different when installing a string + power optimiser system.

An inverter product warranty, also known as a materials warranty, protects the equipment’s structural integrity. Your product warranty kicks in if your solar inverter develops a flaw, has a mechanical problem, or shows excessive wear and tear.

Keep in mind that when searching for the best inverter solution, each will come with a product guarantee, with more extended warranties desired. Most inverter manufacturers offer at least ten years of protection under their product warranties. Those who don’t provide 25 years of coverage generally have the option to extend the contract for a cost.

How To Maintain Your Solar Inverter

An inverter is exceptionally low-maintenance. After you’ve made sure it’s installed correctly, all you have to do now is maintain it clean. Wipe it clean regularly to remove accumulated dust, grime, and cobwebs.

Clean Air Intake

If your inverter is in a dusty location, have the air intake filter cleaned by a technician. You should not try this type of maintenance on your own. Make sure a pro handles it. 

Keep It Cool

Although inverters get heated during everyday use, keeping heat-sensitive or flammable things away from them is crucial. Also, if your inverter has a cooling fan to manage its temperature, ensure it isn’t obstructed and that the airflow around it isn’t restricted. This could cause the inverter to overheat, lowering its efficiency. Allow 12 inches around your inverter for clearance.

Watch for Error Codes

Even if your solar inverter doesn’t require much maintenance, you should check for any error codes from time to time. It’s possible that your inverter needs to be serviced if it displays an error code or a different light than usual. If you observe an error code, call us right away.

Bottom line

Solar inverters are critical components of most solar power systems. Only when DC is used directly, and the system is standalone are exceptions made. Due to technological advancements, the role of solar inverters has evolved, making them multi-functional and valuable in a variety of ways.

If you want to discuss which solar inverter is right for you, Contact Us or Get a Free Quote.

Solar Inverter FAQs

Is an inverter necessary for solar?

For a solar system to work, an inverter is required. It converts the energy gathered by the panels into a safe current.

Can solar panels work without an inverter?

Yes, solar can work without an inverter if DC exclusively powers your load or appliance. An inverter converts DC to AC, allowing us to power our alternating load.

Can I use a solar panel without an inverter and battery?

Batteries are required for off-grid solar panels to work. Batteries are necessary to store electricity in off-grid solar panels. In the absence of electricity or batteries, the only option is to purchase a grid-connected solar inverter.

Can I use a battery without an inverter?

Without an inverter converting a car battery into an outlet is impossible. An inverter, which converts 12V DC (direct current) to 230V AC, would be required (alternating current). Appliances will not run without this electrical gadget.

Do inverters waste power?

Inverters lose electricity when their batteries are not used and the unit is turned on. It is subject to change. Depending on the device and design of their standby systems, they can use as little as .02 amps or as much as two amps.

Why do I need a power inverter?

When installing a solar power system, power inverters convert solar energy into electricity that can be used to power your vehicle’s electronics. This is clean energy that doesn’t deplete your car’s battery.

Do inverters use a lot of electricity?

No, since an inverter consumes about 8-10% more energy than the appliances, it is powering. This is because of the inverter’s efficiency.

Can we use electricity directly from a solar panel?

Yes, this is possible. Having a solar battery backup can be beneficial in some instances, but it is not required. In some cases, the plus solar battery can help, while in others, rooftop solar panels may be the best option.

How often should you wash your solar panels?

As a general guideline, schedule a cleaning at least once every six months, and potentially more frequently if the panels seem to be consistently dirty. One cleaning every six months should suffice if there isn’t much of a problem.

Can you use solar panels without electricity?

Solar panels will not be able to offer electricity to your home or business during a power outage.

What size inverter do I need for solar panels?

It would help match the wattage of your solar panels as a general rule of thumb. You’ll need a 3000-watt inverter if your solar panels are 3000 watts. Oversizing however can be efficient. Most systems are at their peak efficiency at around 120% oversized the solar array. 

How much does an inverter cost?

For an average-sized structure, inverters typically cost $2000 to $3500. However, if the installation grows more extensive, the price may rise quickly.

If you have any further questions, please feel free to Contact Us