Solis S6-EH1P8K-L-PLUS Review UK: 8kW Hybrid Inverter

The Solis S6-EH1P8K-L-PLUS is an 8kW single-phase hybrid inverter built around a low-voltage (40-60V) battery port, two MPPT trackers and a backup output that Solis says switches over in under 4 milliseconds. It sits in the "value-tier" corner of the UK hybrid market. This Solis S6 hybrid inverter review works only from Solis's own S6-EH1P8K-L-PLUS datasheet, so every figure is traceable, and it flags what that document leaves out. It is marked as a preliminary document, so check the current version before you buy.

Solis S6-EH1P8K-L-PLUS at a glance

Solis's datasheet lists these values for the 8K model:

• AC output: 8kW rated and 8kVA maximum, single phase (1/N/PE), 230V, with 36.4A rated and maximum output current at 220V (34.8A at 230V is the second figure on the sheet).
• PV input: two MPPT trackers and up to four strings, 90-435V MPPT range, 500V maximum input, 16A per tracker. Solis recommends a maximum array of 16kW, with 12.8kW the maximum usable PV input power.
• Battery: Li-ion or lead-acid, 40-60V, up to 8kW charge or discharge and 190A maximum current. Communication is by CAN or RS485.
• Efficiency: 96.2% maximum and 94.7% European efficiency. Battery discharge to AC peaks at 94.9%.
• Backup: 8kW rated backup output, 200% of rated power for 10 seconds, and a switchover time under 4ms. The datasheet also lists 50A AC passthrough.
• Build: 335 × 560 × 227mm, 22.2kg, IP66, intelligent redundant fan cooling, operating range −40 to +60°C.
• Interface: LCD display, Bluetooth and app. RS485 and CAN are standard; Wi-Fi, GPRS or LAN are optional extras. AFCI 2.0 arc-fault protection is optional.

Who the Solis S6-EH1P8K-L-PLUS suits

Homes adding a battery from a different brand. A low-voltage battery port means the inverter works with 48V-class batteries rather than one proprietary stack. The datasheet only says Li-ion or lead-acid at 40-60V; it does not list approved batteries, so ask Solis or your installer for the current compatibility list before choosing a battery. Our hybrid inverter buyer guide explains how to match inverter and battery.

Larger single-phase roofs. Two MPPT inputs allow two roof faces on separate strings, and the 16kW recommended array limit leaves room for an oversized array. A UK single-phase connection is limited, though, so see the grid section below before sizing an 8kW system.

Homes that want backup. An 8kW backup output with a sub-4ms switchover is a strong headline figure for the money, and Solis lists generator compatibility and dual backup ports. Battery size, not the inverter, decides how long backup lasts; our home battery backup guide covers realistic runtimes.

What the datasheet does not tell you

It is a preliminary document. The GBR datasheet (version 1.4, June 2024) carries a "Preliminary" watermark. Treat figures as indicative until you have the final sheet or installer paperwork.

Efficiency is modest. A 96.2% maximum is lower than many string-only inverters. That is typical for hybrids, which have more conversion stages, but it matters when comparing against a separate string inverter plus AC-coupled battery. See our best solar inverter guide.

No warranty or UK price. The datasheet states no warranty term and no price. Retailers quote their own terms, so get the warranty period and who handles replacements in writing.

Grid-code listing. The standards list includes NRS 097-2-1, IEC 62116 and IEC 61727 but does not name the UK ENA recommendations. A new UK installation is notified under G98 (up to 3.68kW per phase) or applied for under G99 (larger systems). Ask your installer for the unit's G98 or G99 compliance documentation. Our DNO application guide explains the process, and an 8kW inverter will usually need a G99 application or an export limit.

Solis vs other hybrid options

For a head-to-head against other value and premium stacks, see Sigenergy vs Sungrow vs Solis. Solis's appeal is open battery choice and price; the trade-offs are efficiency and thinner documentation than the premium brands.

Verdict

The S6-EH1P8K-L-PLUS is a capable, feature-rich low-voltage hybrid inverter on paper: 8kW both ways, two trackers, IP66 and fast backup switching. It suits a single-phase home that wants a flexible battery choice and backup. Before you accept a quote, confirm the final datasheet version, the approved battery list, UK G98/G99 compliance and the warranty in writing.