Best solar inverter 2024 guide

A solar panel inverter is a key component of any solar energy system. This device bridges the gap between raw sunshine and usable power for your home or business.

This guide looks at different types of solar panel inverters and offers tips for choosing the one that’s right for you.

Solar panels are composed of photovoltaic (PV) cells. The photons in sunlight hit the PV cells and knock electrons loose, which creates DC electricity. 

However, most homes and appliances operate on AC electricity. DC flows in one constant direction, while AC periodically reverses direction in a wave-like pattern.

Solar panel inverters use a process called inversion to convert steady DC into oscillating AC, which is suitable to use at home and to feed into the power grid.

Inverters also handle other tasks, such as exchanging energy with battery systems.

All solar inverters perform the same basic function of converting DC power from solar panels into AC electricity for consumers. 

However, there are different types of inverters to consider depending on your solar system components, budget and needs.  

String inverters

String inverters are a popular choice among owners of residential and small commercial solar power systems. 

A string inverter converts the combined DC output from a series or “string” of solar panels into AC power. One reason the string inverter is popular is that it’s cost-effective. A single inverter is all you need to convert an entire solar array’s DC output into AC. 

But there is a major drawback to using a string inverter: the performance of the entire string is contingent on every panel operating optimally. A single poorly performing panel negatively impacts the whole string’s efficiency.

Reasons for subpar performance may include the presence of shade or debris, which prevents sunlight from reaching the panel. 

Best suited for:

• Homeowners with tight budgets who are seeking reliable solar energy systems
• Homes with lots of unshaded roof space where all the panels face the same direction 
• Solar systems where you can easily access and maintain your panels

Considerations:

• A string inverter might not be the best fit for homeowners with shade falling unevenly on their roofs or with future plans to expand their solar power systems
• A single malfunctioning panel could shorten the entire solar system’s lifespan

Microinverters

Microinverters are installed beneath individual solar panels. There is a separate microinverter for each panel. Each microinverter turns just one panel’s DC into AC. 

This setup ensures that problems with one panel don’t affect the energy output of others. For example, if shadows fall on a panel and lower its power output, the rest of the array continues operating at peak efficiency.

Microinverters are more expensive than string inverters and aren’t always necessary for simple or compact solar arrays.

Best suited for:

• Homeowners who plan to start small and expand their solar energy systems later
• Homes whose roofs have multiple sections where panels face different directions
• Solar arrays with some panels that get intermittent shade from nearby trees or chimneys

Considerations:

• Installing microinverters requires an initial investment that can be significantly greater than the initial outlay for a string inverter
• Microinverters’ high efficiency and low maintenance costs can make up for their hefty upfront costs over a solar energy system’s lifetime

Hybrid inverters

Like other types of solar panel inverters, hybrid inverters convert DC from solar panels into AC.

Hybrid inverters also connect to battery systems that store DC electricity and convert it to AC as needed. The batteries preserve surplus energy that the solar panels produce during peak sunlight hours. 

Hybrid inverters moderate the flow of electricity between solar panels, batteries, appliances and the power grid. 

You don’t need a hybrid inverter unless you wish to store excess solar energy in batteries for later use.

Best suited for:

• Homeowners who want to store excess electricity produced during the daytime for night-time use
• Homeowners who see solar energy as a long-term investment and are willing to pay a premium for battery storage systems
• Homes in areas that are prone to power outages or that have unreliable power grid connections

Considerations:

• Homeowners must buy battery storage systems that are compatible with their hybrid inverters, which increases the total cost of their solar energy systems
• A hybrid inverter’s initial setup and integration are complex and might require specialised installers

Your inverter plays a significant role in determining how reliable and efficient your solar energy system is and whether you get a good return on investment. So, consider these three factors before choosing an inverter:

Efficiency matters

Inverter efficiency is a measure of how much of the energy your solar panels generate is usable in your home. For instance, an inverter that is 95% efficient loses 5% of the electricity it converts from DC to AC.

Most modern inverters are more than 95% efficient. 

So, when you choose an inverter, it’s important to decide whether greater efficiency is worth the higher price you will pay for it.

The power rating is important

An inverter’s power rating indicates its maximum capacity. While there are various approaches to sizing inverters, the best way to proceed in most situations is to match your inverter’s capacity to your solar panels’ output. 

For instance, if your solar array produces 3kW at peak, the inverter you choose should have a similar rating at the very least.

Future-proofing is desirable

To choose an inverter that’s unlikely to become obsolete, look for features such as mobile apps, dashboards and easy integration with smart home technology. 

Your inverter’s size and compatibility with your array can significantly impact your solar energy system’s overall performance. 

Solar inverter sizing

If your inverter’s capacity is too small, you won’t be able to harness your solar energy system’s full power. But if your inverter’s capacity is too large, you risk inefficiencies and accelerated wear and tear.

Here’s how to proceed: 

1. Start by adding up the wattage of the panels in your array. For instance, 10 300W panels produce a total output of 3kW.
2. Installers sometimes suggest that you choose an inverter that can handle unexpected power surges or potential future expansions. They recommend an inverter with a maximum capacity that’s 10 to 15% greater than your panels’ calculated total output. So, for panels with a total output of 3kW, an ideal inverter size would range from 3.3kW to 3.45kW.
3. In some cases, installers recommend that you undersize your inverter. This practice, which is called “inverter clipping,” can boost your solar energy system’s performance.
4. You should consult a professional if you’re considering inverter clipping. In most situations, it’s wise to choose an inverter with a capacity that closely matches your solar array’s output. If you’re thinking about oversizing your inverter, be aware that many models have 10 to 30% more capacity than their listed wattage rating. 

Installing and maintaining inverters requires you to deal with electrical components, which must be handled with care.

You should always follow the manufacturer’s safety guidelines for installation, but here are some general guidelines for keeping safe:

1. Switch off the system: To minimise the risk of electrical shocks, turn off the entire solar energy system before you begin working on the inverter.
2. Wear safety gear: Appropriate protective gear includes goggles and insulated gloves.
3. Consult a professional: Though you might find do-it-yourself projects appealing, electrical systems’ intricacies can be dauntingly complex. It’s wise to hire a professional to install your inverter and ensure its optimal performance.

Monitoring and data connectivity allow homeowners to keep track of their solar installation’s performance. 

Modern inverters often come with built-in monitoring systems. Look for models with wifi or Ethernet connectivity so you can use dashboards and apps. For instance, the MySolarEdge app provides real-time data about inverters and solar panel arrays.

You might have to purchase a separate communication module that collects data from your solar energy system and makes it available over wifi. 

Monitoring dashboards

Your dashboard tracks metrics such as peak output and daily yield that you should familiarise yourself with. These metrics will reveal inefficiencies in your solar energy system, which you can then address in a timely manner.

Most platforms allow you to customise your notifications. For example, you can get text messages or email alerts if energy production drops below a certain threshold or there is a system fault.

Monitoring inverter data

You should regularly check your solar energy system’s performance metrics. Sharp drops in efficiency or consistent underperformance could mean it’s time to clean your solar panels or do other types of maintenance.

Also, the data will reveal your energy consumption habits and help you figure out how to change them. For instance, you could determine what times of day your solar system produces the greatest amounts of electricity and run your heavy appliances at those times.

Solar panel inverters transform the DC that’s generated by your solar panels into usable AC. 

Consider the merits and drawbacks of different types of inverters to determine which one is the best fit for your solar energy system. 

For the most part, it’s advisable to match your inverter’s maximum capacity and your solar array’s output. But in some circumstances, professional installers recommend the use of undersized inverters to trigger inverter clipping.

Most modern solar panel inverters have wifi or Ethernet connectivity, which simplifies the process of monitoring your system’s performance and your energy-consumption habits.