The Solis 3kW Hybrid 5G Inverter (S5-EH1P3K-L / RHI-3K-48ES-5G) is the smallest single-phase model in the Solis RHI-5G hybrid range, delivering 3,000W AC output with a 3kW backup port that switches in under 20 ms during a power cut. At 3kW, it is the only model in the RHI-5G series with an output below the G98 threshold of 3.68kW: no prior DNO approval required, simply notify within 28 days of connection. This makes it the fastest to deploy of all four models in the range. Two independent 600V DC MPPT trackers, fanless passive cooling, IP65, 7-inch colour LCD, integrated DC switch. 48V lithium battery compatible (Pylontech, Dyness, BYD and others). Recommended max. PV power: 4.8kW. SolisCloud WiFi monitoring, OTA firmware. Certified: IEC/EN 62109-1/-2, BS EN 62109-1/-2 (UK), EN 50549-1, CE, UKCA, TÜV SÜD.
3kW
Rated output
3kW backup
Backup port
2 MPPT
600V DC
>97.1%
Peak efficiency
G98
DNO notify 28 days
IP65 Fanless
Build quality
⚠ Qualified installer required: Installation must be performed by a qualified and MCS-accredited electrician. All wiring must comply with BS 7671 and DNO G98/G99 notification requirements. A DC breaker rated >125 A must be installed between inverter and battery.
ℹ G98 — the smallest Solis hybrid: no prior DNO approval required: At 3.0kW AC output, this is the only model in the RHI-5G range with a grid output strictly below the 3.68kW G98 threshold. The installer notifies the DNO within 28 days after connection. No prior application or waiting period required. Ideal where a 3.6kW or 5kW inverter cannot be justified or where a small, budget-optimised system is the priority.
⚠ Not suitable for lead-acid or lead-carbon batteries: The S5-EH1P / RHI-5G series is designed for 48V lithium-ion (LFP) batteries only. Lead-acid and lead-carbon batteries are not covered under warranty. Confirmed compatible: Pylontech US2000C/US3000C/US5000, Dyness DL5.0C/DL5.0C Pro, BYD B-BOX Premium LVL.
ℹ Eastron SDM630 meter included: Solis supply a 3-phase Eastron SDM630 meter in the box. Despite the three-phase wiring diagram in the manual, Solis confirm this meter can be used in single-phase installations. Use the separate single-phase wiring guide supplement.
How the 3kW Fits in the Solis RHI-5G Hybrid Range
Model
Rated output
Backup port
Battery max
DNO
Best for
★ 3kW (this)
3,000W
3,000W
62.5A
G98
Smallest systems; budget-first; fastest install
3.6kW
3,600W
3,000W
100A
G98
Most domestic rooftops; best value
5kW
5,000W
5,000W
100A
G99
Larger homes; full 5kW backup
6kW
6,000W
5,000W
100A
G99
Maximum PV; high consumption
Note: the 3kW uses the same RHI-5G hardware platform but has a lower max battery current (62.5A) and lower recommended PV input (4.8kW) than the 3.6kW–6kW models. For most domestic new-build systems, the 3.6kW is generally a better specification match at a small price premium. The 3kW suits particularly constrained array sizes or budget-limited systems requiring the G98 simplicity.
Key Features
3kW Output with G98 Simplicity — Notify, Don’t Apply
The 3kW rated output is below the G98 threshold of 3.68kW, making this the only model in the Solis RHI-5G range that does not require G99 prior approval. The installer connects the inverter and submits a G98 notification to the DNO within 28 days. This eliminates the 6 – 12-week wait associated with G99, which is mandatory for the 3.6kW, 5kW and 6kW models. For properties where the electrical installation is otherwise ready and the installer wants to commission immediately, the 3kW is the only choice in this range.
G98 — no prior approvalNotify within 28 days
3kW Backup Port — Less Than 20 ms Switching
The inverter has a dedicated backup port that switches in under 20 ms on grid loss — transparent to most electronics. The backup port is separate from the grid output; it should feed a sub-consumer unit with critical loads only (fridge, lighting, router, phone charging). The backup port must never be connected to the grid. At 3kW, the backup port matches the grid output rating exactly: the entire inverter output is available for backup without any power reduction.
Backup <20ms3kW backup = 3kW grid outputMust NOT connect to grid
97.1% Efficiency — Fanless Passive Cooling, IP65
The S5-EH1P3K-L achieves >97.1% peak conversion efficiency with a transformerless (non-isolated) topology. No fan means no fan noise, no fan failure mode, and no moving parts. The front heatsink dissipates heat passively. IP65 rating means the enclosure is fully sealed against dust and water jets from any direction: suitable for garage, utility room, or sheltered external wall installation.
>97.1% efficiencyFanlessIP65
Dual MPPT, 600V DC — 4.8kW Recommended PV Input
Two independent MPPT trackers allow panels on two string orientations to be optimised separately. Max 600V DC input, MPPT operating range 90 – 520V. Recommended max PV power is 4.8kW DC (slightly lower than the 3.6kW model’s implied 6kW oversizing). MC4 connectors; PV wire 2.5 – 4 mm².
2 MPPT600V DC max4.8kW rec. PV
48V LFP Battery — CAN/RS485 BMS
42 – 58V DC battery connection with CAN/RS485 BMS communication. Max charge/discharge current 62.5A (lower than the 3.6kW–6kW models’ 100A). At 51.2V, 62.5A = approximately 3.2kW of battery throughput — matching the inverter’s 3kW rated output. Compatible: Pylontech US2000C/US3000C/US5000, Dyness DL5.0C, BYD B-BOX and others.
48V LFPCAN/RS48562.5A max charge/discharge
Three Operating Modes + SolisCloud WiFi
Self-consumption: PV powers loads, surplus charges battery, battery discharges at night. Timed charge/discharge: charge from cheap overnight tariff (Octopus Go/Agile), discharge during peak rate. Backup: battery reserved for power cuts. WiFi monitoring via SolisCloud for real-time data and OTA firmware. 7-inch colour LCD for on-unit configuration without phone/internet.
Self-consumptionTimed TOUBackupSolisCloud WiFi
Technical Specifications
Solar PV Input (2 MPPT)
Recommended max. PV power
4.8 kW DC
Max input voltage
600 V DC
MPPT voltage range
90 – 520 V DC
Max input current (per MPPT)
2 × 15A (S5-EH1P) / 2 × 11A (RHI-5G)
PV connectors
MC4 · cable 2.5 – 4 mm²
AC Output (Grid Side)
Rated output power
3,000 W
Max apparent output power
3,300 VA
Max output current
14.5 A (S5-EH1P) / 15.7 A (RHI-5G)
Output voltage / frequency
230 V AC / 50 Hz
AC Backup Port
Backup rated power
3,000 W
Backup output current
13 A
Backup switching time
<20 ms
Battery
Battery type
Li-ion — not suitable for lead-acid
Battery voltage range
42 – 58 V DC (48V class)
Max charge / discharge current
62.5 A DC each
BMS communication
CAN / RS485
DC breaker required
>125 A between inverter and battery
General
Phase
Single-phase 1/N/PE
Efficiency
>97.1 % peak
Cooling
Fanless passive (heatsink)
IP rating
IP65
Operating temperature
−25°C to +60°C
Weight
18.3 kg (approx.)
Display
7-inch colour LCD
Operating modes
Self-consumption, Timed charge/discharge, Backup
Monitoring
SolisCloud (WiFi) — OTA firmware updates
Integrated DC switch
Yes
Standards and Approvals
Safety
IEC/EN 62109-1 & -2, BS EN 62109-1 & -2 (UK)
Grid
EN 50549-1, G98, IEC 61727, IEC 62116
Approvals
CE, UKCA, TÜV SÜD
Frequently Asked Questions
Why choose 3kW over the 3.6kW model?
The 3kW model makes sense in two specific situations. First, if you want absolute simplicity for DNO compliance: both are G98, but the 3kW’s output is meaningfully further below the 3.68kW threshold. Second, if your solar array is small (2 – 3 panels, 1 – 1.5kW) and you only want a modest battery, the 3kW inverter’s lower max charge/discharge current (62.5A vs 100A on the 3.6kW) is a better match. For most new domestic installations, however, the 3.6kW delivers better long-term flexibility at a modest premium and is the more commonly specified choice.
Does this inverter require G98 or G99?
G98. At 3kW rated AC output, this inverter is below the G98 threshold of 3.68kW. The installer connects the inverter and notifies the DNO within 28 days. No prior approval or application is required. This applies for a single inverter on a domestic single-phase supply. Always confirm with the DNO if in doubt, particularly for non-standard installations.
Can I add batteries later if I start with just solar?
Yes. The inverter can operate without a battery — it will function as a standard on-grid inverter. When you are ready to add storage, connect the 48V battery bank to the battery DC terminals and configure the battery type and parameters via the LCD menu or SolisCloud. The inverter will automatically begin managing battery charge and discharge. Ensure the battery brand is on the Solis compatibility list before purchase.
What happens to my loads when the grid fails?
Within 20 ms (typically 10 ms), the inverter switches the backup port load from the grid connection to the battery/PV supply. Any loads connected to the backup port sub-consumer unit will continue operating without interruption. Loads connected to the main consumer unit (non-backup side) will lose power in the normal way. This is why critical loads (fridge, broadband router, phone charging, CCTV) should be on a dedicated backup consumer unit wired to the inverter’s backup port.
Is the Eastron SDM630 meter in the box suitable for a single-phase installation?
Yes. Solis supply a three-phase Eastron SDM630 meter in the box. Despite the main manual showing three-phase wiring diagrams, Solis have confirmed the SDM630 can be used in single-phase installations. Use the dedicated single-phase wiring guide supplement (available on the Solis service portal) — do not follow the meter wiring in the main manual for single-phase.
Related Products
Solis 3.6kW Hybrid 5G Inverter
Next model up — same G98, higher PV input, 100A battery
Solis 5kW Hybrid 5G Inverter
Full 5kW output and 5kW backup — requires G99
Dyness DL5.0C Pro 5.12kWh LFP Battery
Compatible 48V LFP battery module
Pylontech US3000C 3.55kWh Battery
Compatible Pylontech LFP battery
BTU & WATT Calculator
Room Dimensions
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Bathroom
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Glazing Type
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External Walls
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