A solar inverter converts the DC electricity your panels make into the AC electricity your house and the grid run on. Every solar PV system has one, and in Ireland it's also the component the rules attach to: ESB Networks caps a standard home connection at an inverter rated up to 25 amps, about 6 kVA, and the inverter model goes on your NC6 grid notification form. Panels routinely last 25 years or more. Inverters usually don't, which makes the inverter both the brain of the system and its most likely future repair bill.
- String inverter: one box, whole array. The default, and the cheapest.
- Hybrid inverter: a string inverter that can also charge and discharge a battery. What most new Irish installs get.
- Microinverters: a small inverter behind each panel. Dearer, but shading on one panel doesn't drag down the rest.
- The limit: up to 25 amps (about 6 kVA) on a single-phase home under ESB Networks' micro-generation rules.
- Replacement, years from now: Irish installer guides put a like-for-like string swap around €800 to €1,250.
What the Inverter Actually Does
Solar panels produce direct current. Your kettle, your sockets and the national grid all use alternating current at 230 volts. The inverter sits between the two, usually on a wall in the attic, garage or utility room, converting one to the other all day long.
It does more than convert. The inverter tracks the array's output to squeeze the most from whatever light is hitting the roof, shuts the system down safely if the grid goes down, and logs the generation figures you'll see in your monitoring app. When people say their solar "isn't producing", nine times out of ten the question is really about what the inverter is reporting.
String, Hybrid or Micro: The Three Choices
| Type | How it works | Best for |
|---|---|---|
| String | Panels wired in series ("strings") feed one central inverter. | Simple unshaded roofs, lowest cost. |
| Hybrid | A string inverter with a battery connection built in. | Anyone fitting a battery now, or who wants the option later. |
| Micro | A small inverter mounted behind each individual panel. | Shaded or complicated roofs facing several directions. |
The practical difference is shade and layout. On a string inverter, panels in a string behave like a team roped together: heavy shade on one panel pulls down its whole string. Microinverters cut that rope, so each panel does its own thing. On a clear south-facing roof that advantage is worth little. On a roof with a chimney shadow, dormers, or panels split east and west, it can be worth a lot.
Hybrids have quietly become the Irish default because so many systems now include a battery, and because fitting a hybrid now is cheaper than swapping the inverter later when you add one. If a battery is anywhere in your plans, say so at quote stage. It changes which box goes on the wall.
The 25-Amp Rule and Your NC6 Form
Ireland regulates home solar through the inverter, not the panels. ESB Networks defines a micro-generator as one rated up to 25 amps, roughly 6 kVA, on a single-phase connection (or 16 amps, roughly 11 kVA, on three-phase). Stay inside that and connection is free under the "inform and fit" process: your installer submits the NC6 notification form and the grid work costs you nothing.
Two details from ESB Networks' own conditions are worth knowing:
- The inverter must comply with the IS EN 50549-1 standard with Irish settings, and a type test certificate proving it goes in with the NC6 form. Any inverter an SEAI-registered installer fits will meet this, but it's why you can't just import a random unit and wire it up.
- Since 31 May 2023, units with a rated current above 25 amps on their type test are not accepted through the micro-generation route at all, even if they're marketed as "6 kW" models. Checking this is your installer's job.
Bigger than 25 amps means the mini-generation process instead, with more paperwork and possible network studies. For a normal house it's rarely worth it. Note the limit is on the inverter's output, not the panel array: installers commonly fit more panel capacity than the inverter's rating, since Irish roofs rarely deliver full rated output anyway.
The Brands on Irish Quotes
Get three quotes in Ireland in 2026 and you'll likely see some of the same names: Sigenergy hybrid systems have become a favourite on battery installs, with Huawei, Solis, Sungrow and Fronius all common. None of these is a wrong answer. The honest advice is that a mid-market inverter fitted by a good installer beats a premium inverter fitted by a bad one, because workmanship and support decide how the system behaves over 25 years.
What matters more than the badge:
- The warranty term, and whether the installer or the manufacturer handles a claim.
- Battery compatibility, since hybrids typically pair best with their own maker's battery.
- The monitoring app, which you'll look at weekly for years.
- Whether your installer can still get parts for it in year eight.
Lifespan, Warranties and What a Replacement Costs
Panels degrade slowly and are usually warrantied for 25 years or more. Inverters work harder, run warmer, and give out sooner. Irish installer guides put a string or hybrid inverter's working life at around 10 to 15 years, with manufacturer warranties typically 5 to 10 years and extensions often available. Microinverter makers quote much longer lives, with warranties up to 25 years, which is part of what you're paying for.
When a replacement is eventually needed, the same guides put a like-for-like string inverter swap at roughly €800 to €1,250 supplied and fitted, and a hybrid replacement at roughly €1,100 to €1,650. Individual microinverters run around €250 to €350 each, though they rarely all fail at once. Treat these as planning figures, not quotes; prices move with the euro-dollar exchange rate and the model fitted.
The 0% VAT rate on home solar applies to solar panels and their ancillary equipment, the inverter included, when they're supplied and installed together under the same contract. That's Revenue's rule, and it's why your original install is zero-rated end to end. A standalone inverter replacement years later isn't a supply-and-install of solar panels, so expect VAT on the job, and ask the installer how it's applied when you're comparing prices.
Is There a Grant for the Inverter?
Not a separate one. The SEAI Solar Electricity Grant, up to €1,800 in 2026, is paid on the installed system as a whole, and the inverter is simply part of what it covers. There is no SEAI grant for replacing an inverter on an existing system, so budget for that yourself somewhere in the second decade.
The inverter is also part of how your export income works. It's the inverter that pushes your surplus onto the grid to earn the Clean Export Guarantee, which is one more reason the box should be sized and configured by someone who does this daily.
You Don't Pick the Inverter. You Pick the Installer.
Nobody sizes their own inverter, and nobody should. Your installer matches the inverter to your roof, your usage, your battery plans and the 25-amp limit, then stands over the choice. What you can do is compare what different installers propose and ask why. If one quote specs a plain string inverter and another specs a hybrid for similar money, that's a real difference in what your system can do in 2031, and worth a question now.
Solar Quotes Ireland matches you with SEAI-registered installers in your county. Ask each one what inverter they'd fit on your roof and why. It's the fastest way to tell a good proposal from a cheap one. No obligation, no cost.
Get free solar quotes →Frequently Asked Questions
What does a solar inverter do?
It converts the DC electricity your solar panels generate into 230V AC electricity your home and the grid use. It also maximises the array's output, shuts the system down safely during a power cut, and provides the generation data shown in your monitoring app.
What size inverter can I have in Ireland?
Up to 25 amps, about 6 kVA, on a standard single-phase home connection under ESB Networks' micro-generation rules, or 16 amps (about 11 kVA) on three-phase. The inverter must comply with IS EN 50549-1 with Irish settings, and since 31 May 2023 units type-tested above 25 amps are not accepted through the NC6 micro-generation route.
What is the difference between a string inverter and a hybrid inverter?
A string inverter converts solar power for your home and the grid. A hybrid inverter does the same but can also charge and discharge a home battery. Hybrids cost more upfront but avoid a second inverter, or an inverter swap, if you add a battery later.
How long does a solar inverter last?
Irish installer guides put string and hybrid inverters at around 10 to 15 years of working life, against 25 years or more for the panels, so most systems will need one inverter replacement in their lifetime. Microinverters are typically warrantied for much longer, up to 25 years.
How much does it cost to replace a solar inverter in Ireland?
Roughly €800 to €1,250 for a like-for-like string inverter replacement and roughly €1,100 to €1,650 for a hybrid, supplied and fitted, according to Irish installer guides in 2026. A standalone replacement does not qualify for the 0% solar VAT rate, which only applies when panels and equipment are supplied and installed together, so check how VAT is applied on the quote.
Is there an SEAI grant for a solar inverter?
Not on its own. The SEAI Solar Electricity Grant of up to €1,800 covers the installed system as a whole, inverter included, on a new installation. There is no grant for replacing the inverter on an existing system.