--- title: "SMA Solar STP4.0-3AV-40 (Sunny Tripower 4.0) Grid-tie Inverter: Specs & Datasheet | ComparePV" description: "SMA Solar STP4.0-3AV-40 (Sunny Tripower 4.0) 4 kW grid-tie inverter. Specs: 97.1% European efficiency, 2 MPPT, 850 V max DC input, 17.0 kg, 5 yrs warranty." source: "https://comparepv.com/inverter/sma-solar-stp4-0-3av-40-sunny-tripower-4-0" updated: 2026-01-16 --- # SMA Solar STP4.0-3AV-40 (Sunny Tripower 4.0) ## Identity - **Manufacturer:** SMA Solar - **Model:** STP4.0-3AV-40 (Sunny Tripower 4.0) - **Series:** Sunny Tripower - **Rated AC power:** 4 kW - **Type:** Grid-tie - **Phases:** Three-phase ## How it compares Compared against 362 inverters from 3 to 6 kW. Ranks are within that class. | Measure | This inverter | Class median | Standing | Rank in class | | --- | --- | --- | --- | --- | | European efficiency | 97.1% | 97.2% | Typical | 148 | | MPPT trackers | 2 | 2 | Typical | 13 | | Max DC input voltage | 850 V | 600 V | Typical | 88 | | Weight per kW | 4.2 | 3.3 | Typical | 239 | | Warranty | 5 yrs | 5 yrs | Typical | 34 | ## Specification ### AC output - **Rated AC power:** 4 kW - **Max apparent power:** 4.00 kVA - **Phases:** Three-phase - **Nominal AC voltage:** 230 V - **Max AC current:** 6.1 A - **Grid frequency:** 50 Hz - **Power factor:** 1 (at rated power); adjustable displacement PF: 0.8 overexcited to 0.8 underexcited ### PV input - **Max DC input power:** 8.00 kW - **Max DC voltage:** 850 V - **MPPT voltage range:** 140 to 800 V - **Start-up voltage:** 175 V - **MPPT trackers:** 2 - **Max input current per MPPT:** 12.0 A - **Max short-circuit current per MPPT:** 18.0 A ### Efficiency - **European efficiency:** 97.1 % - **Max efficiency:** 98.2 % ### Physical - **Dimensions:** 470 × 435 × 176 mm - **Weight:** 17.0 kg - **Enclosure:** IP65 - **Cooling:** natural - **Noise:** 30 dB - **Operating temperature:** -25 to 60 °C - **Max humidity:** 100 % ### Connectivity and protection - **Interfaces:** Wi-Fi, Ethernet - **Protocols:** Modbus (SMA), Modbus (SunSpec), Webconnect, SMA Data, Speedwire (Ethernet), WLAN - **Protection:** DC switch ### Warranty and certificates - **Warranty:** 5 years - **Certifications:** AS4777.2, C10/11, CE, CEI 0-21, DEWA 2016, DIN EN 62109-1 / IEC 62109-1, DIN EN 62109-2 / IEC 62109-2, DK1/2 Typ A, EN 50549-1, EN 62116, G98-1, G99-1, IEC 61727, IE-EN 50438, NEN-EN 50438, NRS 097-2-1, PPDS, PPC, RD 1699, SI 4777.2, TOR Erzeuger Typ A, UTE C15-712, VDE-AR-N 4105, VDE-0126-1-1, VFR 2014 ### Pros - **European Efficiency ~97.9%** - The Sunny Tripower X models achieve a European efficiency of ~97.9%, outperforming direct competitors: Fronius Symo Advanced (~97.25%) and Fronius Symo Lite (~97.58%). Over a full year of operation, a difference of 0.5-0.7 percentage points translates into measurably higher energy yield with no additional investment. - **ShadeFix Without Power Optimizers** - SMA ShadeFix is a software-based maximum power point optimization routine that runs cyclically at the string level. The manufacturer states that in many partial shading scenarios it matches or exceeds the performance of hardware optimizers (e.g., SolarEdge P-Series), eliminating the cost of additional devices and reducing potential failure points. - **Two Independent MPPTs** - The standard dual independent MPPT inputs allow strings with different orientations or shading exposure to be connected without cross-losses. In typical Central European rooftop conditions (dual-pitch roofs, SE/SW-facing strings), this is a key design advantage that simplifies system layout and minimizes mismatch losses. - **Smart Energy Hybrid Variant** - The Sunny Tripower Smart Energy line (5-10 kW) provides three-phase hybrid operation with battery storage, backup power mode, and intelligent self-consumption management - all in a single unit. The Smart Energy version is certified for use with BYD HVM/HVS batteries and SMA Home Storage. - **Tier-1 Standing and Comprehensive SMA Ecosystem** - SMA has maintained Tier-1 ranking for over a decade. The SMA Sunny Portal / ennexOS platform supports monitoring via Wi-Fi and Ethernet, along with API integration, facilitating remote servicing. The service network and availability of spare parts is well-established compared to smaller manufacturers. ### Cons - **Premium Pricing vs. the Market** - SMA Sunny Tripower inverters are consistently priced higher than comparable models from Huawei SUN2000 and Sungrow SG - the difference is estimated at 15-30% depending on the distributor - and are similarly priced to Fronius. For CAPEX-sensitive investors, the premium can be difficult to justify, particularly in prosumer installations without demanding shading conditions. - **Sunny Portal App - Reported Shortcomings** - Users and installers report instability in the Sunny Portal mobile app, including intermittent data gaps, incomplete production statistics, and a limited charting range compared to competing platforms (e.g., Fronius Solar.web, Huawei FusionSolar). This is not a fault of the inverter itself, but it may detract from the day-to-day monitoring experience. - **Late Entry into Three-Phase Hybrid** - The three-phase Smart Energy hybrid variant did not become available until 2022, whereas the Fronius GEN24 Plus launched in 2020 and the Huawei SUN2000-L1 in 2019. The battery ecosystem and backup functionality are therefore less mature, which may be a concern for customers planning more complex off-grid or backup-capable systems. ## About this series The SMA Sunny Tripower series are three-phase grid-tie inverters for residential and commercial installations, designed for stable operation under Polish grid conditions. What sets them apart is the **advanced shading management SMA ShadeFix**, which helps maintain high yields without needing additional optimizers, and **typically two independent MPPTs** - making it easier to split the generator into two strings with different roof orientations or varying shading levels, minimizing losses. In practice, this translates to high **European efficiency**, meaning truly good energy conversion in typical, variable daily sunlight conditions. Another advantage is the **extensive communication and monitoring** - depending on the version, options include among others WiFi, Ethernet, and integration with the SMA ecosystem for monitoring the installation’s performance in the app and portal. Additionally, certain variants of the Sunny Tripower (Smart Energy) are hybrid, supporting energy storage systems and offering an emergency power supply mode. The series meets required standards and certifications (including CE), and the standard manufacturer’s warranty can be extended by registering the unit. ## Questions ### What is SMA ShadeFix technology and does it truly replace power optimizers? SMA ShadeFix is built-in shade management software that intelligently tracks the maximum power point (MPP) and minimizes losses when part of the array is shaded by a chimney, tree, or dormers. The manufacturer has integrated it into the inverter at no additional cost, which means that in most residential installations there is no need to purchase separate optimizers for each module. In practice, this translates into higher annual energy yield without extra expense. ### What warranty does SMA offer on Sunny Tripower series inverters? The standard manufacturer's warranty for the Sunny Tripower series is 5 years. After registering the unit on the SMA platform, it can be extended for a fee to 10, 15, or even 20 years, in accordance with the current SMA warranty price list. This is one of the longest warranty extension options available in the three-phase inverter market. ### Is the Sunny Tripower inverter suitable for installations with panels on two roof sections at different azimuths? Yes, the Sunny Tripower series is typically equipped with two independent MPPT inputs (voltage range 140-800 V each). Each input optimizes power independently, so panels on a south-facing section and an east- or west-facing section operate without mutual losses. This is a practical and more cost-effective solution than using two separate inverters. ### What is the European efficiency of Sunny Tripower inverters and what does it mean in practice? Depending on the model, the European efficiency of the Sunny Tripower series ranges from approximately 97.9% (X models) to 98.4% (CORE2). European efficiency accounts for the variable irradiance conditions typical of Central European climates, making it a more accurate representation of real-world energy losses than peak efficiency. The higher the value, the more of the generated energy reaches the grid or storage system. ### Does the Sunny Tripower Smart Energy support backup power supply to the home during a grid outage? Yes, the Sunny Tripower Smart Energy (hybrid) version has a built-in backup power function. Following a grid outage, it automatically disconnects from the utility grid and within approximately 30 ms switches the connected circuits to power supplied by the battery and the PV array. A prerequisite for this function is a connected and sufficiently charged energy storage system. Available power ratings are 5, 6, 8, and 10 kW. ### How can I monitor the operation of a Sunny Tripower inverter, and do I need a separate device for that? The Sunny Tripower features built-in Wi-Fi or Ethernet communication (depending on the version), allowing the inverter to connect directly to the SMA ecosystem. Production and system operation data are accessible via the SMA mobile app and the SMA Sunny Portal without the need to purchase separate data loggers. The SMA Smart Connected service also enables remote notification of the installer in the event of any faults. ## Datasheet [Manufacturer datasheet (PDF)](https://comparepv.com/datasheets/inverters/stp3-6-3av-40-ds-en-41-f70d96aff9de.pdf) ## Alternatives | Inverter | Rated AC | Euro efficiency | MPPT | Weight | Difference | | --- | --- | --- | --- | --- | --- | | [SolarEdge EV Charging Single Phase Inverter SE4000H (aka H4000SE / SE4000H)](https://comparepv.com/inverter/solaredge-solaredge-ev-charging-single-phase-inverter-se4000h-aka-h4000se-se4000h) | 4 kW | 99.0% | | 11.4 kg | +1.9 pp efficiency, 5.6 kg lighter | | [SolarEdge SE4000H (HD‑Wave, single phase)](https://comparepv.com/inverter/solaredge-solaredge-se4000h-hd-wave-single-phase) | 4 kW | 98.8% | | 9.0 kg | +1.7 pp efficiency, 8.0 kg lighter | | [Solis-3P4K-4G](https://comparepv.com/inverter/ginlong-solis-solis-3p4k-4g) | 4 kW | 97.8% | 2 | 17.3 kg | +0.7 pp efficiency | | [Ginlong Solis S6-GR3P-4K02-NV-ND](https://comparepv.com/inverter/ginlong-solis-s6-gr3p-4k02-nv-nd) | 4 kW | 97.7% | 2 | 14.7 kg | +0.6 pp efficiency, 2.3 kg lighter | | [GoodWe GW4K-DT](https://comparepv.com/inverter/goodwe-gw4k-dt) | 4 kW | 97.6% | 2 | 15.0 kg | +0.5 pp efficiency, 2.0 kg lighter | | [Growatt MOD 4000TL3-X](https://comparepv.com/inverter/growatt-mod-4000tl3-x) | 4 kW | 97.5% | 2 | 12.5 kg | +0.4 pp efficiency, 4.5 kg lighter | | [Growatt MOD 4000TL3-X2 (Pro)](https://comparepv.com/inverter/growatt-mod-4000tl3-x2-pro) | 4 kW | 97.5% | 2 | 14.6 kg | +0.4 pp efficiency, 2.4 kg lighter | | [SOFAR 4.4KTLX-G3](https://comparepv.com/inverter/sofar-solar-sofar-4-4ktlx-g3) | 4 kW | 97.5% | 2 | 17.0 kg | +0.4 pp efficiency | --- Source: https://comparepv.com/inverter/sma-solar-stp4-0-3av-40-sunny-tripower-4-0