Solis
S6-GR1P3.6K
3.6kW single-phase string inverter. No proprietary ecosystem — works with any panels and any battery.
~£549
How it scores
Scores based on published manufacturer specifications and weighted criteria — not lab testing. Methodology.
Specifications
- KW
- 3.6
- Mppt
- 2
- Phase
- single
- Efficiency %
- 97.6
- Warranty years
- 10
What I noticed
The Solis S6 is the go-to budget-conscious choice for a shading-free roof. Two MPPT inputs let you connect two separate panel strings — useful if you're splitting panels across two roof pitches.
Who it suits
Simple unshaded installations where you don't want vendor lock-in. Open protocol means you can pair any compatible battery and monitor with any third-party system (Home Assistant, SolarLog, etc.).
Watch for
No built-in optimizers — if you have any shading, consider SolarEdge or micro-inverters instead. The 10-year warranty is standard but shorter than SolarEdge's 12 years.