What the inverter does
- Converts DC to grid-quality AC.
- Tracks the maximum power point (MPPT) as sunlight changes.
- Synchronises with the grid's voltage and frequency.
- Protects: shuts down during outages (anti-islanding) and on faults.
- Reports: most models log generation and send it to a phone app.
String vs micro vs hybrid
| Item | String inverter | Microinverters | Hybrid inverter |
|---|---|---|---|
| Where | Wall-mounted, one per system | One behind each panel (or pair) | Wall-mounted with battery |
| Cost | Lowest | Highest | Medium–high |
| Shading tolerance | Good with multiple MPPTs | Best | Good |
| Backup in outage | No | No | Yes (with battery) |
| Service access | Easy, at eye level | On the roof | Easy |
| Best for | Most homes and businesses | Complex, shaded, multi-angle roofs | Outage-prone sites |
Sizing the inverter
The inverter is normally rated close to the array size — a 3 kW array with a 3 kW inverter. A DC:AC ratio slightly above 1 (e.g. 3.3 kWp of panels on a 3 kW inverter) is common and improves morning and evening output with minimal clipping at noon. If you plan to expand, an inverter one size larger saves replacing it later.
Single-phase or three-phase
Your inverter must match your connection. Homes up to about 5 kW are often single-phase; larger homes and businesses are usually three-phase. We check your sanctioned load and phase during the survey.
Datasheet checklist
- Max efficiency and European/weighted efficiency (≥97%)
- Number of MPPT inputs (two helps split roofs)
- IP65 or better for outdoor/semi-outdoor mounting
- Built-in DC switch, surge protection (SPD) and anti-islanding
- Wi-Fi monitoring and a local service network
- Warranty length and how claims are handled
Where it goes
We mount inverters at eye level, in shade where possible, with ventilation around them — inverters derate when hot. In the photos on our projects page you'll see them on stair-headroom walls with the AC and DC distribution boxes beside them.