How to Choose the Best Solar Panel Inverter

Project Solar UK
Published: June 18, 2021

If you want a solar panel system that is working at its best, you’ll want to ensure each component is of the highest quality. In our latest blog post, we’re focusing on inverters so you can find the best solar panel inverter for your system. 

What is a solar panel inverter?

Let’s start with the basics. If you want to find the best solar panel inverter, it’s good to know what it is. Simply put, a solar inverter is an electric converter that takes the direct current (DC) electricity generated by solar panels and converts it into alternating current (AC). Alternating current is the standard electricity flow that is required for domestic appliances and electrical circuits. So, in a nutshell, a solar inverter ensures your electricity is fit for its purpose. 

What is the purpose of a solar panel inverter?

A high-quality solar panel inverter is a crucial element of your solar panel setup. Intelligent technology connects to your system and fulfils two jobs: 

  • Maximise the available energy that your solar panels have generated. 
  • Ensures your electricity is fit for purpose, converting it from DC to AC. 

How does a solar panel inverter work? 

A solar inverter works in three simple steps:

  • DC electricity generated from your solar panels and channelled through a transformer.
  • The transformer then lowers the voltage and converts it to AC electricity.
  • The DC runs through two or more transistors. The transistors are rapidly switched on and off to feed both sides of the same transformer.

Now that we’ve covered what a solar inverter is and how it works, let’s get down to business. It’s time to arm you with all of the information you’ll need to find the best solar panel inverter for you. 

Types of solar panel inverters 

There are several types of solar inverters on the market. Today, we will look at three of the most common options: string inverters, microinverters and an optimised inverter system. 

String Inverter 

String inverters have been around for some time now. With a string inverter, solar panels are sorted into groups or rows, with each panel installed on a ‘string’. Once installed, you can connect multiple strings to a single inverter, transforming DC electricity to AC electricity. Pros: 

  • Proven technology that has been used for decades. 
  • Often the most cost-effective option on the market. 

Cons:

  • If the performance on one panel is reduced by cloud coverage or damage, the performance of the whole group or row can be impacted. 
  • No option to review the performance of single panels without a power optimiser. 

Micro Inverters 

Microinverters are a popular choice when it comes to residential solar panel systems. A micro inverter is fitted to each individual solar panel, converting DC to AC on your roof. Pros: 

  • Microinverters remove the necessity of a separate inverter. 
  • They allow you to monitor the performance of each individual solar panel.
  • They’re a good option for those installing additional solar panels on their roof.
  • If one or more panels are affected by shade, it won’t impact any panels that are in sunlight.

Cons:  

  • Microinverters are relatively new to the market, typically meaning they are more expensive than other options. With that said, the increased cost could be offset by increased energy production. 

Optimised inverter system

You could also choose to opt for an optimised inverter system. This is a system that uses string inverters and power optimisers, which will ensure you’re getting the best performance from your solar panels. Similarly to micro-inverters, power optimisers are also located on each individual panel, offering many of the same benefits. The key difference between the two is that a power optimiser works with a string inverter. Rather than converting DC to AC at roof level, a power optimiser will move the DC electricity to a string inventor, which will convert it to AC. With power optimisers, you should have the ability to monitor the performance of each individual panel using an online portal. 

Solar inverter energy output 

You may think things are getting a little complicated now, but the energy output of your solar inverter is also essential. Typically, your inverter will produce one of three types of energy.

  • Sine wave – the majority of household items work on a sine wave, so you can expect your devices to work with full specification. 
  • Modified sine wave – all household items will also work on modified sine wave; however, they’ll have low efficiency. This means your devices will use more power due to low efficiency. 
  • Square wave – this type is seldom used, although it is used to operate universal motors without any issues. 

Choosing the best solar panel inverter for you

It’s time to get down to the nitty-gritty so that you can choose the best solar panel inverter to suit your individual needs. There is no one-size-fits-all option with many different types, brands, sizes, and models on the market. While you may want to consult an expert in all things solar, below are some of the key factors you should consider when choosing a solar panel inverter. Safety certificationFirst and foremost, you should ensure your inverter of choice has been certified by an independent testing laboratory. BudgetUltimately, your budget will impact your decision when it comes to choosing the best solar panel inverter for you. Rather than simply going for the most affordable option on the market, we recommend considering other factors to ensure you’re getting the best value for money. When shopping around, you’ll want to keep efficiency, longevity and your specific requirements in mind. Our expert team can help you find the right product to suit your budget and requirements.Size capacity You’ll need to know how much energy you want to generate from your solar panels to make an informed decision on the size capacity required from your inverter system. Top tip: because of system losses that may occur in solar panels, you should consider investing in an inverter that’s got a slightly higher capacity than what you want. This will boost your chances of collecting optimal energy. Efficiency The ratio of output power to input power is used to measure the efficiency of solar panel inverters. The efficiency of solar panels depends on several factors, so it’s difficult to achieve 100 per cent. Warranty and service Good inverters can last as long as 20 years, requiring little maintenance. However, you’ll want a decent warranty and level of customer service in case things do go wrong. More often than not, solar inverters come as part of a complete solar panel installation. So, take your time to choose a reputable company that offers a good warranty and service level. Expandability If you intend to expand your solar panel system in the future (many people do), it’s an important consideration. Until you need to upgrade your inverter system, you’ll want to get the most out of your current inverter. Top tip: a maximum power point tracking inverter might be the best option for you if you plan to expand in the near future. We know that finding the best solar panel inverter may seem a bit overwhelming, but a good solar panel inverter is a key component to ensure you’re reaping the benefits of your panels. So, it’s not something that shouldn’t be overlooked. As always, our knowledge and friendly team are on hand to help you with any queries or concerns regarding your solar panel system.