How to choose the right solar inverter for your home

This blog outlines the purpose, function, and types of inverters to guide potential solar users in deciding the best home solar inverter.

Readers will learn about the key factors to consider when choosing an inverter, including power capacity, optimal DC-to-AC ratio, and compatibility of their specific solar setup. By understanding these aspects, users can make an informed decision that optimises their solar system's performance and meets their energy needs.

What is the Purpose of the Inverter?

Solar panels, also known as photovoltaic (PV) modules, are the primary energy source in a solar system. They capture sunlight and convert it into direct current (DC) through the photovoltaic effect. However, this DC cannot be directly used in homes and businesses, which rely on alternating current (AC) for power.

This is where solar inverters come into play. The solar inverter will convert the DC into AC that will be used to power household devices or fed into the grid. Beyond this primary function, modern solar inverters optimise the solar system by using Maximum Power Point Tracking (MPPT) to ensure solar panels operate at peak efficiency under varying conditions. Not to mention, many modern inverters are often equipped with monitoring capabilities which allow users to track energy production and consumption, alongside providing safety mechanisms to quickly shut down the system in case of electrical faults, enhancing overall safety.

In essence, the inverter serves as the control centre for the solar system to operate smoothly.

What are the Different Types of Inverters?

Solar systems rely on different types of inverters to convert DC into usable AC, each offering unique features and benefits for different applications.

String Inverters

String inverters are the most common type used in residential and commercial solar installations. They convert DC from multiple solar panels into AC for household or business use. Modern string inverters feature MPPT(s) to monitor and maximise the efficiency of each panel string. These devices optimise power output, handle varying sunlight conditions, and ensure the system operates at peak performance. String inverters are cost-effective and suitable for installations with consistent sunlight exposure across all panels.

Microinverters

Microinverters are the smallest inverter out of the 4 types, designed to operate at the individual panel level in photovoltaic systems. These units are installed directly beneath each solar panel, converting DC generated by the panel into grid-compatible AC on-site. Unlike central or string inverters that handle multiple panels, microinverters perform power conversion for a single panel. This panel-level approach allows for independent operation and optimisation of each solar module within the system. Microinverters typically incorporate Maximum Power Point Tracking (MPPT) technology to ensure optimal energy harvesting under various conditions. They are equipped with monitoring capabilities that provide detailed performance data for each panel, enabling precise system diagnostics.

Hybrid Inverters

Hybrid inverters are the most versatile of the four inverter types, combining the functions of solar and battery inverters into a single unit. They convert DC from solar panels into AC for electric loads while managing battery charging and discharging to create an energy storage system. These inverters can operate in both grid-tied and off-grid configurations, making them adaptable to changing energy needs. Hybrid inverters are ideal for users seeking future-proof systems that can accommodate retrofitted batteries as energy consumption increases. They offer advanced features such as load prioritisation, time-of-use optimisation, and seamless switching between power sources, enhancing energy independence and efficiency. Hybrid inverters offer long-term flexibility and potential cost savings for users seeking grid-tied energy storage systems capable of exporting power back to the grid.

Off-grid Inverters

Off-grid inverters are designed to operate independently from the utility grid, converting DC electricity from solar panels into AC electricity for household use. Unlike grid-tied inverters, they don't export power back to the grid but instead incorporate battery charging capabilities and energy storage management. This allows for continuous power supply even without sunlight. These inverters feature advanced functionalities such as load management, generator integration, and system monitoring, ensuring reliable operation in remote environments. Off-grid inverters are crucial for enabling energy independence in locations with poor or no grid access, offering a complete solution for standalone inverter systems.

How to Decide Solar Inverter Capacity for Home?

Choosing the right solar inverter for your home involves matching its capacity to the solar panel system size, considering the inverter’s DC-to-AC conversion ratio, and evaluating power needs.

Total Panel Capacity

The inverter's capacity should generally match or slightly exceed the total wattage of the user’s solar panel array. The inverter must be able to handle the power input from the solar panels; exceeding the inverter’s limit will result in excess power being clipped, leading to energy losses during peak production periods. However, slightly oversizing the panel capacity relative to the inverter can improve overall system efficiency by generating more energy during low-light conditions, such as early mornings and late afternoons. This practice of slight oversizing maximises the inverter’s performance without exceeding its operational limits.

DC to AC Conversion Ratio

A DC-to-AC ratio between 1 and 1.5 optimises solar system performance and efficiency by accounting for inverter clipping while maximising energy production. Oversizing the solar array relative to the inverter capacity can lead to some power loss during peak periods but often results in higher overall energy yield, especially during low-light conditions. This approach effectively balances cost and output, as it increases overall energy harvest without significantly raising system costs, given that solar panels have become relatively cheaper than inverters. This approach allows solar users to optimise their solar investment, achieving better performance and potentially higher returns over the system's lifetime.

Power Needs

A solar user's power needs are crucial in determining the appropriate inverter capacity for their home or business. By understanding daily electricity consumption patterns, users can identify the optimal inverter size to handle peak loads and ensure efficient energy conversion. It's also important to consider potential future increases in energy needs, as selecting a slightly larger inverter can accommodate system expansion. To make an informed decision, users should start by calculating their estimated daily load consumption. This information, when provided to installers or distributors, helps in selecting an inverter that caters to specific energy requirements. By carefully assessing both current and anticipated power needs, users can ensure their solar system is well-equipped to meet present and future energy demands.

How Do You Choose an Inverter for Your Home?

To choose the right inverter for your home, it's important to assess the size of the solar installation, potential for future expansion, quality certification of the inverter, and after-sales service of the chosen inverter brand.

Size of the Solar Installation

To accurately plan a solar installation, users need to consider the available space in their home or business. Microinverters are suitable for smaller installations as they can be installed beneath solar panels, minimising the amount of space needed. However, they may be less economical for future expansions, as additional microinverters would be needed to expand the solar system. For larger homes and businesses, string and hybrid inverters are still ideal choices, as they can process more DC input at a central location, though they require more space. Ultimately, the available installation space influences the size and type of solar installation, guiding the choice of the types of chosen inverters.

Future Expansion

A solar user should understand the differences among the four types of inverters. Of these, hybrid inverters are suitable for users planning future upgrades, particularly the addition of battery storage systems. Many users prefer using hybrid inverters without initially investing in solar batteries. In this case, choosing a hybrid inverter can serve as a grid-tied inverter. When the user decides to upgrade the existing hybrid system into an energy storage system, the hybrid inverter offers flexibility without incurring additional costs for a separate battery inverter. Most hybrid inverters can seamlessly convert DC to AC to power electric loads and vice versa to charge solar batteries. Therefore, users planning to expand their inverter system in the future would benefit from installing a hybrid inverter.

Quality Certification

When choosing an inverter for your home, focus on three key types of quality assurance: safety, performance, and grid compatibility. Safety certifications like UL 1741 and IEC 62109 ensure the inverter meets strict standards, reducing risks of electrical hazards. Performance standards such as IEC 61683 verify efficiency claims, helping users select inverters that maximise their solar system's output. For grid-tied inverter systems, compatibility certifications like IEEE 1547 confirm a safe connection to the utility grid. Additionally, reliability certifications from renowned labs like TÜV Rheinland provide further assurance of the inverter's quality. To ensure your inverter meets high standards, check with manufacturers for multiple certifications across these categories.

After-Sales Service

When choosing the best home solar inverter, users should consider the quality of after-sales support offered by the manufacturer. A reputable brand like Growatt provides responsive assistance for troubleshooting, warranty claims, and maintenance guidance. Growatt offers quick technical support to diagnose and resolve issues, minimising system downtime and economic losses. Users need to verify that the manufacturer has clear, easily accessible warranty policies and guidelines on their website. Additionally, Growatt provides a comprehensive maintenance guide with step-by-step instructions and visual aid to help homeowners and business owners perform preventive maintenance on their inverters. This level of support ensures users can maximise the performance and longevity of their solar investment while having peace of mind about ongoing technical support.

Best Home Solar Inverter

According to S&P Global’s latest release of its PV Inverter Market Tracker, Growatt is the world’s no.1 residential PV inverter exporter by shipments in 2022, which offers some of the best residential inverters globally. Check out our wide range of inverters that are suitable for residential, commercial, and utility applications.

Growatt’s Microinverters: NEO 600-1000M-X, NEO 2000M-X

Growatt’s Residential PV Inverters: MIC 750-3300TL-X, MIN 2500-6000TL-X, MIN 7000-10000TL-X/X2, MOD 3-15KTL3-X

Growatt’s Residential Storage Inverters (Hybrid): MIN 2500-6000TL-XH, MIN 2500-5000TL-XA, MOD 3000-10000TL3-XH, SPH 3000-6000TL BL-UP, SPH 10000TL-HU, SPH 4000-10000TL3 BH-UP, SPA 4000-10000TL3 BH-UP, MIN 30000-11400TL-XH-US

Growatt’s Commercial & Industrial PV Inverters: MID 11-30KTL3-XH, MID 15-25KTL3-X, MID 25-40KTL3-X, MID 30-50KTL3-X2, MAC 50-70KTL3-X LV/MV, MAX 50-80KTL3 LV, MAX 100-150KTL3-X LV/MV, MAX 100-150KTL3-X2 LV/MV

Growatt’s Commercial Storage Inverters (Hybrid): WIT 50-100K-HU/AU, WIT 50-100K-HU/AU-US, WIT 28-55K-HU/AU-US L2, WIT 29.9-50K-XHU

Growatt’s Utility-Scale PV Inverters: MAX 185-253KTL3-X HV

Solar Inverter Troubleshooting and Maintenance

In conclusion, selecting the right inverter for your home involves a comprehensive understanding of the user’s energy needs, inverter types, and specifications. The troubleshooting and maintenance aspects of the inverter are also important considerations. Growatt users benefit from Operations and Maintenance (O&M) applications like ShinePhone (Apple OR Andriod) and ShineServer, which enable efficient monitoring of inverter performance and help identify potential causes of technical issues.

For those seeking personalised guidance, Growatt's sales team offers free consultation sessions, providing in-depth explanations of their inverter range, which spans from 0.75kW to 250kW. By considering these factors and utilising available resources, homeowners can make an informed decision, ensuring their solar system operates at peak efficiency for years to come.