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SMA Solar STP 125-70 (Sunny Tripower 125)

125 kW Grid-tie Three-phase
Compare with closest alternative Datasheet PDF
Rated AC (kW)
125.00
Typical for its class
Euro eff. (%)
98.1
Weak · bottom 4%
MPPT
12
Strong · top 14%
Max DC (V)
1100
Typical · median 1100 V
Weight (kg)
96.0
Weak · bottom 11%
Warranty (yrs)
5
Typical · median 5 yrs

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.

Ranking

95 inverters from 100 to 500 kW
Metric This inverter Median Position in class Rank in class
European efficiency 98.1% 98.6% Weak · bottom 4% 57
MPPT trackers 12 10 Strong · top 14% 3
Max DC input voltage 1100 V 1100 V Typical 47
Weight per kW 0.8 0.6 Weak · bottom 11% 84
Warranty 5 yrs 5 yrs Typical 2
Colour key Strong - top 25% Typical - middle 50% Weak - bottom 25%

Specifications

Open datasheet PDF
Rated AC power 125 kW Continuous output
Max apparent power 125.00 kVA
Phases Three-phase
Nominal AC voltage 400 V 320 V to 480 V
Max AC current 181.1 A
Grid frequency 50 Hz Range 45 Hz to 65 Hz
Power factor 0.8 overexcited (leading) to 0.8 underexcited (lagging)
Harmonic distortion (THD) 3.0 %
Max DC input power 187.50 kW DC/AC ratio 1.50
Max DC voltage 1100 V Caps the string length
MPPT voltage range 180 to 1000 V
Start-up voltage 200 V
MPPT trackers 12 2 strings each
Max input current per MPPT 30.0 A Must exceed the panel's Imp
Max short-circuit current per MPPT 40.0 A Must exceed the panel's Isc
European efficiency 98.1 % Weighted across part loads
Max efficiency 98.4 % Best single operating point
Dimensions 795 × 1020 × 360 mm Height × width × depth
Weight 96.0 kg 0.8 kg per kW
Enclosure IP65
Cooling forced-air
Noise 71 dB
Operating temperature -25 to 60 °C
Interfaces Wi-FiEthernetDisplay
Protocols SMA ModbusSunSpec ModbusSpeedwire
Protection AFCIDC switchSurge protection
Warranty 5 years Standard manufacturer cover
Certifications G99CEI 0-21CEI 0-16EN 50549-1/-2:2018EN 50549-10:2022IEC 62109-1IEC 62109-2NA/EEA-NE7VDE-AR-N 4105/4110/4120:2018

Pros and cons

5 positive · 3 caution
What owners get
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.

Trade-offs
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.

Inverter Power Euro eff. MPPT Weight Difference
SMA Solar STP 125-70 (Sunny Tripower 125) 125 kW 98.1% 12 96.0 kg You are here
S5-GC125K-HV 125 kW 98.6% 10 91.0 kg +0.5 pp efficiency, -2 MPPT, 5.0 kg lighter
MAX 125KTL3-X LV 125 kW 98.4% 10 84.0 kg +0.3 pp efficiency, -2 MPPT, 12.0 kg lighter
SG125CX-P2 125 kW 98.3% 12 93.0 kg 3.0 kg lighter
SOFAR 125KTLX-G4-A 125 kW 98.3% 10 75.0 kg -2 MPPT, 21.0 kg lighter
S6-GC125K 125 kW 98.3% 10 96.0 kg -2 MPPT
S6-GC125K-HV 125 kW 98.3% 10 96.0 kg -2 MPPT
MAX 125KTL3-X2 LV 125 kW - 8 84.0 kg -4 MPPT, 12.0 kg lighter
MAX 125KTL3-X2 MV 125 kW - 8 84.0 kg -4 MPPT, 12.0 kg lighter

About the Sunny Tripower series

6 answered

These answers cover the whole series. Where a figure differs, the specification above is this model's own.

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.
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