Inverters
Fronius Symo Light 6.0-3-M 6kW Three-Phase
Austrian-engineered premium 3-phase string inverter. 6kW with dual MPPT, IP66 rated for outdoor install.
£891.12 ex VAT
How it scores
Scores based on published manufacturer specifications and weighted criteria — not lab testing. Methodology.
Specifications
- Supply phase
- three
- Hybrid inverter
- No
- Max power (kW)
- 6
- IP rating
- IP65
- Weight kg
- 19.9
- MPPT trackers
- 2
- Dimensions mm
- 645x431x204
- Warranty
- 10
- Optimisers required
- No
- Peak efficiency
- 98
What I noticed
Fronius is the premium European inverter brand, headquartered in Austria with manufacturing in Europe. The Symo Light 6.0-3-M is the 6kW three-phase residential variant — designed for larger UK homes with three-phase supply or commercial-light installs.
Three-phase design eliminates phase-imbalance issues that affect single-phase inverters on high-load homes. Dual MPPT, IP65 outdoor rating, and Fronius's exceptional build quality (often cited as the longest-lasting inverter brand in the market) justify the premium price.
Who it suits
Larger homes (5+ bed) with existing three-phase supply, or installs where build quality and Austrian-engineered reliability matter more than upfront price. Strong choice for properties where the inverter will be wall-mounted in a protected outdoor location.
What I'd watch for
Requires three-phase supply — verify with DNO before specifying. Premium pricing — for single-phase value-tier installs the Growatt or Solis are better picks. UK installer familiarity is high but specialist (less of a 'default brand' than Growatt/Solis).
Sources — verified 4 June 2026
- Fronius International, “Fronius Symo 3.0-20.0 kW Datasheet” — fronius.com
Symo Light 6.0-3-M 6kW Three-Phase head-to-heads
Side-by-side scoring vs each alternative in our shortlist.
Other Inverters on my shortlist
Read next
Background reading and decision-tree pages that put this product in context.