Grid Tied Inverter - Three Phase - High Efficiency
A grid-tied inverter, also known as a string inverter, combines several solar panels into strings and feeds their electricity into the domestic grid and the public grid. It has no battery connection and is therefore the device of choice for PV systems designed without storage. The range comprises 23 models from 800 W to 125 kW from Solplanet, Growatt, SunGrow, Huawei and Fronius.
Single-phase for small roofs, three-phase from 6 kW
Single-phase units have a single phase for grid feed-in. They range from 800 W to 6 kW and are suitable for carports, garages and small roofs. Three-phase units start at 6 kW and are the standard choice for detached houses and larger areas.
| Power | Phases | Units in the range | MPP trackers |
|---|---|---|---|
| 0.8 to 3 kW | single-phase | Growatt MIC TL-X | 1 |
| 3.6 to 6 kW | single-phase | SunGrow SG RS, Solplanet ASW S-G2 | 2 |
| 6 to 20 kW | three-phase | Solplanet ASW LT-G2 Pro, Fronius Symo GEN24 12.0 | 2 |
| 25 to 60 kW | three-phase | Solplanet ASW LT-G3, Huawei SUN2000-36KTL-M3 | 3 to 5 |
| 125 kW | three-phase | SunGrow SG125CX-P2 | 12 |
Key considerations for system design
The rated power depends on the module power. The data sheets specify a maximum recommended module power, which for most units here is 1.4 to 1.5 times the AC power. An Solplanet ASW 10K-LT-G2 Pro can therefore handle up to 15 kWp, whilst an Growatt MIC 3000TL-X can handle up to 4.2 kWp.
The number of MPP trackers determines how many differently oriented roof areas can be operated separately. One tracker is sufficient for one roof area; two are required for an east-west-facing roof. The maximum input voltage for single-phase units is 500 to 600 V, and for three-phase units 1,000 to 1,100 V; this limits the number of modules that may be connected in series in a string. According to the data sheet, the European efficiency rating is between 96.5 and 98.4 per cent.
The units are protected to IP65 or IP66 and are designed for external wall installation. The manufacturer’s warranty is ten years; for the Huawei SUN2000-36KTL-M3 it is five years.
If you plan to add a storage system later
A grid-tied inverter cannot accommodate a battery. Anyone who can already foresee the need for a battery is better off planning for a hybrid inverter from the outset. For an existing system, there are two ways to retrofit: the Growatt SPA 6000TL3 BH-UP, which is added on the AC side, and the EcoFlow PowerOcean DC Fit converter from the inverter accessories range, which, according to the manufacturer, connects the battery on the DC side.
In the event of a power cut, grid-tied devices switch off. One exception is the Fronius Symo GEN24 12.0, which, according to the catalogue, has an emergency power function; this requires an additional switch-over device. The ‘Inverter Overview’ table compares all models.
For photovoltaic systems and their essential components, no value added tax is charged where the conditions of Section 12 (3) of the German VAT Act (UStG) are met. You state during the ordering process whether they apply to you.
Frequently asked questions about grid-tied inverters
What is the difference between a string inverter and a hybrid inverter?
Both convert the module current. The hybrid inverter also has a battery connection and controls charging and discharging, whilst the string inverter only feeds into the grid.
Which string inverter is suitable for 10 kWp?
A three-phase unit with 8 or 10 kW. According to the data sheet, the Solplanet ASW 8K-LT-G2 Pro can handle up to 12 kWp, whilst the ASW 10K-LT-G2 Pro can handle up to 15 kWp.
Can I store electricity with a grid-tied inverter?
Not directly. A storage system can only be connected via an additional device, such as the Growatt SPA or the EcoFlow PowerOcean DC Fit converter, or the inverter must be replaced with a hybrid inverter.