Solar Panel Inverters: What are they & How do they work?

At the heart of a solar energy system lies a key player that operates behind the scenes but is vital to the process – the solar panel inverter. 

In this article, we'll explore what solar panel inverters are, how they work, and the different types available. 

What is a Solar Panel Inverter?

A solar panel inverter is a component that converts the direct current (DC) electricity produced by solar panels into alternating current (AC) electricity, which is used to power your home. Essentially, it acts as a bridge, transforming the electricity into a form that your household appliances and the power grid can use.

Imagine the inverter as the conductor of an orchestra. While solar panels generate DC electricity from sunlight, most household devices and the electrical grid operate on AC electricity. The inverter coordinates these two types of electricity, ensuring that your home can effectively use the clean, renewable energy captured from the sun.‍

Solar Optimisers Explained

Solar Optimisers are often used in conjunction with solar inverters. They are small components that can be connected to each solar panel in your system. Their primary role is to ensure that each panel operates at its peak efficiency, regardless of the varying levels of shade or sunlight exposure they might encounter throughout the day.

Whilst we only need to know the above to understand solar inverters better, you can dive into our article on what are solar optimisers for an in-depth breakdown.

How Do Solar Panel Inverters Work?

With an understanding of what solar panel inverters and optimisers are, it's time to delve into how solar inverters work. 

Solar inverters ensure that the electricity produced by your solar panels is compatible with your home's electrical system. Here's a simplified breakdown of how this conversion process unfolds:

1. DC to AC Conversion: The solar inverter takes the DC power generated by your solar panels and converts it into AC power. This process involves changing the electrical current's direction, creating a waveform that is similar to the electricity supplied by utility companies.

2. Stable Voltage and Frequency: In addition to converting the current type, the inverter stabilises the voltage and frequency of the electricity. This ensures that the power supplied to your home is consistent and reliable.

3. Synchronisation with the Grid: For grid-connected solar systems, the inverter synchronises the solar-generated electricity with the electrical grid. This allows excess power to be fed back into the grid as part of the smart export guarantee. 

Maximum Power Point Tracking (MPPT)

A key feature of many solar inverters is Maximum Power Point Tracking (MPPT). This technology is crucial for optimising the energy output of your solar panels. 

Solar panels perform at their best when they receive direct sunlight. However, real-world conditions are rarely perfect—shadows, cloud cover, and variations in panel temperature can all affect their performance. 

MPPT technology addresses these challenges by constantly monitoring and adjusting the voltage and current to keep each panel operating at its optimal power point, even when conditions aren't ideal. Essentially, it ensures that your solar panels generate the maximum amount of electricity possible, enhancing the overall energy production of your solar system.

‍Recommended Article:Do Solar Panels Need to be In Direct Sunlight?

Types of Solar Panel Inverters

When selecting a solar panel inverter for your residential solar system, it's crucial to consider the different types available. Each type offers distinct features and benefits, allowing you to tailor your choice to your specific needs and circumstances. 

Note: We won't delve into central inverters, as they are typically used in large-scale solar installations and not meant for residential use.

String Inverters

String inverters connect multiple solar panels in series, forming a string. All panels within a single string are typically at the same height and orientation. This configuration ensures uniformity in electrical characteristics. 

String inverters usually have connections for multiple strings, allowing you to have panels on different sides of the house without the need for optimisers. This makes them perfect for east/west-facing roofs, where the panels receive sunlight at different times of the day.

Pros:

Cost-Effective: String inverters are usually more budget-friendly compared to other inverter types.

‍Reduced Efficiency: If one panel on a string underperforms due to shading or a fault, it can affect the entire string's performance.

‍Easy Maintenance: Simplified design makes them easy to maintain and repair.

Cons:

‍Design Limitations: May not be suitable for installations where panels have varying orientations and heights, or face different directions. However, this can be worked around if there are enough connections on the inverter.

‍Proven Technology: They are a popular choice for residential use, with a history of reliable performance.

Microinverters

Microinverters offer a unique approach by providing each solar panel with an inverter. These inverters sit directly under the panels and convert the electricity there. With our microinverter systems there’s no need for a main inverter elsewhere in the property. 

In this setup, every panel operates independently, which means that if shading or a fault occurs on one panel, it doesn't affect the others. This design can enhance your solar panels' energy production by 5-30% compared to string inverters, but it typically comes at a higher cost.

Pros:

Optimised Performance: Each panel operates at its maximum capacity, even if other panels are shaded or underperforming.‍

‍Easy Installation: Microinverters simplify the installation process as there is no need to string panels together.

‍Monitoring Capabilities: Microinverters often come with advanced monitoring systems that allow you to track the performance of each panel.

Cons:

Maintenance Complexity: As there are more individual components, potential maintenance could be more intricate.

Higher Cost: Microinverters are typically more expensive than string inverters due to their advanced technology.

Power Optimisers

Power optimisers are devices that are installed behind each solar panel in a system using a string inverter. They serve the function of optimising the electrical output of each panel. Much like microinverters, power optimisers prevent shading or fault issues on one panel from affecting the performance of the entire string. Without them, one shaded panel would bring the other panels down to its level, dramatically decreasing your energy production.

Pros:

Enhanced Efficiency: Power optimisers can improve the energy production of your solar panels by mitigating issues that affect a single panel's output.

‍Flexible Design: They offer greater flexibility in terms of panel placement, allowing you to harness energy even if panels face varying directions.

Cons:

Higher Cost: Like microinverters, power optimisers come at an additional cost compared to string inverters.

‍Hybrid Inverters

Hybrid inverters are essentially just string inverters that are also compatible with batteries. Thus allowing your system to store excess solar energy. 

Hybrid inverters can intelligently manage the flow of the electricity generated by your solar panels, directing it to where it’s needed most; whether it’s powering your home, charging the battery, or exporting to the grid. 

Enhanced Efficiency: Hybrid inverters combine the benefits of both string and micro-inverters, offering improved energy production and performance optimisation.

‍Moderate Cost: While more budget-friendly than microinverters, hybrid inverters can be costlier than traditional string inverters.

‍Cost-Efficiency: They strike a balance between microinverters' higher cost and the lower cost of string inverters.

‍Compatibility Check: Like power optimisers, compatibility with your central inverter is a crucial consideration.

Do I need Inverters for my solar panels?

Without a solar panel inverter, the energy produced by your solar panels would be unsuitable for powering your home. So, whether you opt for string inverters, microinverters, power optimisers, or hybrid inverters, these devices are essential for transforming solar energy into a usable power source. 

How much does a solar inverter cost in the UK?

The cost of a solar inverter in the UK can vary significantly depending on several factors, including the type of inverter you choose, your specific energy needs, and the quality of the inverter. Here's a general overview of the price range for different types of solar inverters:

String Inverters - Prices typically range from £500 to £1500, making them one of the more budget-friendly options.

Microinverters - On average, microinverters cost between £150 and £200 each. For a system with 10 panels, you might be looking at a total cost of £1500 to £2000

Power Optimisers -  Power optimisers typically cost about £50 each each but require a string inverter as well. 

Hybrid Inverters - The cost of hybrid inverters can range from £1200 to £1500.

The right choice of inverter can make a significant difference in the efficiency and performance of your solar panel system, leading to greater energy savings and potentially a faster return on your solar investment.

Which solar inverter is right for you?

For personalised recommendations on the best solar inverter and panels for your specific needs, consider using our solar panel tool. This tool takes into account your location, energy goals, and budget, to provide tailored suggestions to help you harness the full potential of solar energy.

Or if you’d prefer to do it yourself, here's a quick guide to help you make an informed decision:

1. System Size and Configuration - Consider the size and configuration of your solar panel system. Larger systems may benefit from microinverters or hybrid inverters, while smaller systems can work well with string inverters.

2. Budget Considerations - Your budget plays a significant role in your inverter choice. String inverters are typically the most cost-effective, while microinverters and hybrid inverters come at a higher price point. 

3. Efficiency and Performance - Assess the efficiency and performance of the inverter type. Microinverters and hybrid inverters are known for their efficiency, especially in scenarios with shading or panel faults.

4. Maintenance Requirements - Consider the maintenance needs of different inverter types. While string inverters are relatively low-maintenance, microinverters and optimisers may require more attention over time.

Final Thoughts

Solar panel inverters are often the unsung heroes of your solar energy system. By making well-informed choices about your solar inverter, you can enhance your solar panel’s energy production, reduce costs, and support a more sustainable future.

To help you find the perfect inverter and solar panels for your needs, we offer a user-friendly solar panel tool. Just provide some details about your property and energy usage, and our tool will calculate and deliver a detailed breakdown of your potential investment.

Don’t forget to explore our other green guides. You might find our comprehensive solar panel guide useful, or you could check out our latest insights on whether solar panels are worth it.

Recommended Guides:

- How many solar panels can i fit on my roof?

- Do solar panels need to be in direct sunlight?

- Are solar panels worth it in the uk?

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