SMA Sunny Boy Smart Energy 4.0
A 4kW residential hybrid inverter with 3 MPPTs, EPS backup power and the SMA Home Storage battery ecosystem, built for a fixed rooftop solar system.
Characteristics
- Power: 4000W, single-phase, 3 MPPTs
- Solar input: 8000W max
- Battery: SMA Home Storage, up to 13.12kWh
- Safety: 3680W emergency power supply (EPS)
- 3 MPPTs, EPS backup and the SMA Home Storage ecosystem
Detailed overview: SMA 4kW hybrid inverter for the home
The SMA Sunny Boy Smart Energy 4.0 is a hybrid inverter for a fixed, grid-tied solar installation on a house roof, quite different from a plug and play balcony micro-inverter or a portable power station. Unveiled at Intersolar 2024, it combines PV conversion and home battery management in a single unit.
It carries three independent MPPT trackers, handling up to 8000W of panels in total across a 60 to 480V range, enough to cover several roof orientations without a performance penalty. AC conversion tops out at 4000W, single-phase. Unlike some rivals, the Sunny Boy Smart Energy 4.0 doesn't include a built-in battery: it pairs with the SMA Home Storage ecosystem, 3.28kWh modules that combine up to 4 units (13.12kWh total), chosen separately to match budget and desired backup runtime.
During a grid outage, a 3680W emergency power supply (EPS) output keeps essential circuits running, more a continuity feature than a full whole-home backup. SMA's ShadeFix technology continuously re-optimises output when a panel is partially shaded, and the zero feed-in mode prevents surplus export where a grid connection doesn't allow it.
Control runs through the SMA app (Ethernet and Wi-Fi), with detailed tracking of production, consumption and battery state of charge. The unit measures 500 x 586 x 236mm and weighs about 17.5kg, with peak efficiency near 97.5 to 98%. The manufacturer warranty runs 10 years. It's a sound pick for anyone building a full, expandable home energy system rather than shopping for a standalone inverter at the lowest price, backed by SMA's well-established engineering reputation.
Full specifications
Detailed characteristics
Battery
| Expandable up to?Maximum capacity reachable with add-on modules. | 13120 Wh |
|---|
Power and protection
| Output power?Maximum power delivered (for storages with a 230 V output). | 4000 W |
|---|
Solar section
| MPPT controllers?Number of built-in MPPT solar controllers (lets you connect panels facing different directions). | 3 |
|---|---|
| Max solar input?Maximum connectable PV power. | 8000 W |
| Micro-inverter?Power of the inverter that feeds energy back into the home grid. | 4000 W |
Connectivity
| Wi-Fi?Remote control and updates over Wi-Fi. | Yes |
|---|
Durability and format
| Weight?Weight of the battery. | 17.5 kg |
|---|---|
| Dimensions (L × W × H)?Length × width × height, in millimetres. | 500 × 586 × 236 mm |
Availability and warranty
| Market launch?Date the model first became available on the European market. Useful to place its generation: technology moves fast in this segment, and a device several years old may be at the end of its commercial life. | June 2024 |
|---|---|
| Warranty?Length of the manufacturer's warranty. | 10 years |
Comparison
How does the SMA Sunny Boy Smart Energy 4.0 stack up against other residential hybrid inverters?
| Criterion | SMA Sunny Boy Smart Energy 4.0 | Huawei SUN2000-3K-LB0 | Kostal PLENTICORE plus 4.2 |
|---|---|---|---|
| AC power | 4000W, single-phase | 3000W, single-phase | 4200W, three-phase |
| MPPTs | 3 | 2 | 3 |
| Outage backup | EPS, 3680W | ~20ms (with LUNA2000) | Depends on battery setup |
| Battery | SMA Home Storage (external, up to 13.12kWh) | LUNA2000 (external, plug and play) | BYD HVS/HVM (external) |
| Warranty | 10 years | 10 years | 5 years (10 with activation) |
The SMA stands out with its three independent MPPTs and ShadeFix, a real advantage on a multi-face or partially shaded roof. Against the Huawei, notably cheaper for a more modest power rating, the SMA targets a heavier-consumption home. Against the Kostal, three-phase and built for larger homes, the SMA stays single-phase but with comparable power. A sound choice for anyone who values the brand and an expandable storage ecosystem over the lowest entry price.
Related video
Video: Field Tested | Product Review: SMA Sunny Boy Smart Energy
Our tester's review: Julien De Jurquet
The Smart Energy 4.0 lives up to SMA's reputation: three MPPTs rather than two (a real plus if the roof has several faces), ShadeFix that limits the damage when a chimney or tree shades a panel, and a clear app that shows production, consumption and battery state without unnecessary jargon. The EPS backup switchover worked as advertised in our simulated outage tests, with one honest limit: it only covers 3680W, so not the whole house at once, just essential circuits if the consumer unit is set up for it beforehand. Since it stores nothing on its own, the real budget climbs fast once you add one or more SMA Home Storage modules, making this a pick for anyone aiming at the full ecosystem rather than the cheapest standalone inverter. One more thing worth knowing before signing: several customer reviews flag SMA's after-sales support as slow for warranty replacements at times. Still a solid, thoroughly German unit for a home that genuinely wants to manage its production and consumption.
Frequently asked questions: SMA 4kW hybrid inverter for the home
No, the inverter doesn't store energy on its own. It pairs with one or more SMA Home Storage modules (3.28kWh each, up to 4 modules for 13.12kWh total), sold separately to match the backup runtime you want.
The EPS output delivers up to 3680W, enough for essential circuits (fridge, lighting, router, a few sockets) if the consumer unit is prepared beforehand, but not enough to run the whole house at once.
Up to 8000W spread across three independent MPPT inputs, for an AC output capped at 4000W. That headroom lets you oversize the panel array for better output on overcast days.
It's an SMA technology that continuously re-optimises each string of panels when part of the array is shaded by a chimney, tree or cloud, limiting the production loss across the whole system.
Yes, like any residential inverter wired into the consumer unit, installation must be carried out by a qualified electrician and registered with the grid operator before commissioning.
Need help choosing?
Other products in the "Hybrid residential inverters" category
EG4 12kPV Hybrid Inverter
£2224.00
The EG4 12kPV turns up to 12000 W of solar into 8000 W of usable household power, charges your batteries and can sell the surplus back to the grid.
Huawei SUN2000-3K-LB0
£684.47
A 3kW residential hybrid inverter compatible with the LUNA2000 battery: 2 independent MPPTs, IP66 protection and a 10-year warranty for your roof.
Kostal PLENTICORE plus 4.2
£1151.00
A three-phase 4.2kW residential hybrid inverter with 3 MPPTs and smart battery management: the German pick for a well-equipped home.
Sol-Ark 15K Hybrid Inverter
£3707.00
The Sol-Ark 15K delivers up to 15000 W continuous, accepts 19500 W of solar across 3 MPPT trackers, and switches to backup in 5 ms to protect the whole house.
Published on 04/09/2026