The essentials in 30 seconds
A solar panel inverter converts the direct current (DC) your panels generate into alternating current (AC), which your appliances and the grid use, the DOE explains. It does this by switching the DC back and forth very rapidly and filtering it into a clean sine wave. A home inverter usually also monitors the system. There are three common layouts: a string inverter (one inverter for a row of panels; cost-effective, but shading or a fault on one panel reduces the whole string), microinverters (one per panel; one shaded panel doesn't affect the others, but they can cost more) and power optimizers (a device on each panel working with a central inverter). Batteries can be charged over DC or after conversion to AC. The Energy Saving Trust says panels should last 25 years or more, but the inverter needs replacing after around 12 years; warranties are at least five years, often extendable to 15.
- Ask whether your system will keep working in a power cut: most won't without a battery and the right inverter.
- Installation is a job for a certified installer: MCS in the UK, NABCEP in the U.S.
What a solar inverter does
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Converts
Panels produce DC at a constant voltage in one direction; the inverter turns it into AC, whose voltage alternates between positive and negative.
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Shapes the output
Filters and electronics produce a clean, repeating sine wave that can be fed into the grid without damaging equipment built for set voltages and frequencies.
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Monitors
Most home inverters monitor the system and connect to the internet; the Energy Saving Trust says some can email you if the system fails.
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Supports the grid
Inverters are designed to "ride through" small voltage or frequency disturbances and to disconnect if a disruption is long or large (DOE).
The DOE calls the inverter one of the most important pieces of equipment in a solar system.
String inverters, microinverters and optimizers
| Type | Where it sits | Strength | Watch out for |
|---|---|---|---|
| String inverter | One inverter for a set of panels (a string) | Cost-effective | Shading or a problem on one panel reduces the whole string's output |
| Microinverters | A small inverter on every panel | Shading or damage on one panel doesn't affect the others | Can be more expensive |
| Power optimizers | A device on each panel, with a central inverter doing the DC-to-AC conversion | Panel-level output and monitoring, less loss from shading | Check compatibility with the inverter |
| Central inverter | One inverter for a whole utility or community plant | Large scale | Not used on homes |
SolarEdge says its optimizers reduce losses from shading and panel mismatch and let you monitor every panel in an app. The DOE's point about strings is the key one for most homes: if part of your roof is shaded for part of the day, ask your installer whether microinverters or optimizers are worth the extra cost.
Hybrid inverters and battery storage
The DOE says batteries can be charged directly over DC or after a conversion to AC. In practice that gives two layouts:
- Hybrid inverter: one inverter handles the panels and the battery, which is charged on the DC side.
- Separate battery inverter: the solar inverter stays as it is and the battery is charged from the AC side, through its own inverter.
The Energy Saving Trust suggests asking for battery quotes at the same time as the panels; if you might add one later, ask the installer which layout your inverter allows.
Does a solar inverter work when the grid goes down?
Usually not. Grid-connected inverters are designed to disconnect when the grid has a long or large disruption, the DOE says. Solar-plus-battery systems use advanced inverters that can run without the grid in an outage, if they are designed to do so. If backup power matters to you, it has to be specified from the start: the inverter, the battery and which circuits it will power.
Inverter lifespan, warranties and faults
- Lifespan: panels 25 years or more; inverter replaced after about 12 years (Energy Saving Trust).
- Warranty: at least five years on most inverters, often extendable up to 15 years. The Energy Saving Trust notes a 15-year warranty can cost almost as much as a replacement inverter, so weigh it up.
- Faults: your installer should leave written maintenance checks, including the inverter's main fault signals and troubleshooting steps. Check the inverter display or app now and then; a fault light or zero output usually means calling the installer.
- Replacement: because panels outlast inverters, a failed inverter normally means replacing the inverter, not the whole system. Our how long do solar panels last guide covers panel ageing.
How to choose an inverter for your solar panels
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01
Shade
Little or no shade and a simple roof: a string inverter is the cost-effective choice. Partial shade or panels on several roof faces: consider microinverters or optimizers.
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02
Battery plans
Fitting a battery now or later? Ask whether a hybrid inverter or a separate battery inverter makes sense.
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Backup
Do you want power during outages? Only some inverter and battery combinations do it.
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Monitoring
Panel-level (microinverters, optimizers) or system-level (string).
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Warranty and service
Length, what extension costs, and who replaces it.
Costs depend on the system and region; see solar panel cost UK and solar panel cost US.
Solar panel inverters: FAQs
What does an inverter do in a solar panel system?
It converts the DC electricity the panels produce into AC for your home and the grid, as a clean sine wave, and usually monitors the system.
Which is better, a string inverter or microinverters?
String inverters are cost-effective; microinverters cost more but stop one shaded or damaged panel from reducing the others' output, according to the DOE.
What is a hybrid inverter for solar panels?
One inverter that handles both the panels and a battery, charging the battery on the DC side.
How long does a solar inverter last?
The Energy Saving Trust says to expect to replace it after around 12 years, while the panels last 25 years or more.
Will my solar panels work in a power cut?
Usually not: grid-tied inverters disconnect. Only systems with a battery and an inverter designed for backup keep running.
Sources
Government, energy advice and manufacturer pages, checked on 3 November 2026 (03/11/2026).
- U.S. Department of Energy · Solar integration: inverters and grid services basics ↗DC to AC; switching and sine wave; monitoring; backup only if designed; ride-through and disconnection; central, string and microinverters; batteries charged over DC or after AC conversion. Read.
- U.S. Department of Energy · Homeowner's guide to solar ↗Install through a qualified professional; NABCEP certification. Read.
- Energy Saving Trust · Solar panels: costs, savings and benefits ↗Inverter turns DC into AC; panels 25 years or more, inverter replaced after around 12; monitoring emails; warranties of 5 years extendable to 15; maintenance checks and fault signals; MCS-certified installers; battery quotes. Read.
- SolarEdge · Residential power optimizers ↗Mitigate shading, clipping and mismatch; panel-level monitoring; optimized inverters. Read.
Getting quotes?
Ask each installer which inverter type suits your roof's shade, how a battery could be added, and what the inverter warranty covers.