Inverters & components
Solar inverters: how they work and the types explained
Solar panels produce direct current (DC), but your home and the grid run on alternating current (AC). The inverter is the device that converts one to the other — and it does much more besides, including the safety functions that let generation connect to the mains.This hub explains what inverters do and how the main types differ, so you can see why plug-in solar is built around the microinverter.
Written and edited by Christopher Panteli
Christopher is the founder and editor of MyPlugInSolar. He oversees the site’s research standards, data tools and editorial process. He is not an electrician or solar installer, and specialist technical claims are sourced from official documentation or reviewed by appropriately qualified professionals.
What a solar inverter actually does
Beyond DC-to-AC conversion, a modern inverter tracks the panels' optimum operating point (maximum power point tracking, or MPPT) to extract as much energy as conditions allow, matches its output to the grid's voltage and frequency, and disconnects safely if the grid goes down. That last function — anti-islanding — stops a system feeding electricity into wires that should be dead, and is essential for safety. We cover it in anti-islanding explained.
The three main types
For a focused comparison of the first two, see microinverter vs string inverter.
| Type | How it works | Typical use |
|---|---|---|
| String inverter | One central unit converts several panels wired in series | Whole-roof rooftop systems |
| Microinverter | A small inverter per panel or pair of panels | Plug-in solar and panel-level rooftop systems |
| Hybrid inverter | Combines solar conversion with battery charge/discharge | Solar-plus-storage systems |
Why plug-in solar uses microinverters
Plug-in systems are small — one or two panels — and need to produce mains-compatible AC at the panel itself so the output can connect through a lead rather than a roof-mounted string inverter. A microinverter does exactly that, with built-in grid protection. Learn more in our microinverters guide, and how to check a microinverter suits your panels in microinverter compatibility.
UK rules
What to look for in a microinverter
- Reputable manufacturer with clear documentation and certification.
- Appropriate AC output rating (commonly 800W for plug-in systems).
- Built-in grid protection and rapid shutdown.
- Monitoring so you can see what the system is doing — see solar panel monitoring.
Safety and compliance
Frequently asked questions
- What is the difference between a string inverter and a microinverter?
- A string inverter is one central unit converting several panels wired together; a microinverter is a small unit per panel (or pair). Microinverters handle shading better and suit small plug-in systems, while string inverters are common on larger rooftop installs.
- Do I need a separate inverter for plug-in solar?
- No — plug-in solar kits include a microinverter, usually rated around 800W. It converts the panels' DC to mains-compatible AC and provides the required grid-protection functions.
Sources
- 1. Engineering Recommendation G98 (connecting small generation) — Energy Networks Association
- 2. BS 7671 Requirements for Electrical Installations (IET Wiring Regulations) — Institution of Engineering and Technology
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Related guides
- Microinverters explainedThe component at the heart of plug-in solar.Read more
- Microinverter vs string inverterA focused comparison of the two approaches.Read more
- Anti-islanding explainedThe grid-protection function that keeps wires safe.Read more
- Solar panel monitoringSeeing what your system is really doing.Read more
- Is plug-in solar legal in the UK?The current rules on connecting generation.Read more