Inverters from KOSTAL – equipped for 400W solar modules

Solar module manufacturers are responding to the growing demand for energy by adapting photovoltaic cells. New primary materials, changes in the manufacturing process of semiconductors, and the optimisation of production costs provide the solar market with larger wafers, which are needed for the production of photovoltaic cells.

Even now, the total solar module production using the larger wafers and a rated output of 54 gigawatts makes up about half of the module designs available on the market in 2021.

KOSTAL’s 400W Modules

Until recently, photovoltaic cells with an edge length of 166 millimetres were normally connected as a whole or as half cells in solar modules. The new cell sizes of 182 mm or even 210 mm have a new structure and change the module dimensions.

For example, 108 millimetres of the new 182 mm half cells are interconnected in modules (M10 wafers) for the home environment. The larger cells make the module slightly wider (approximately 1.14 metres). However, fewer cells are interconnected internally than in the previous generations with 120 half cells.

Fewer cell gaps mean higher module efficiency as more active area is used. A module with 108 half cells achieves an efficiency of 20.46% with a 400W output (for example, the Suntech STP405S).

Manufacturers who use cells with an edge length of 210 mm made of so-called M12 wafers take a different approach. For modules in the home environment, these are divided into three equal one-third cells and interconnected again to form 120 one-third cells in one module.

The larger cells are structured in a new cell matrix with 5 x 24 one-third cells. Since only five strips of cells are then installed, the modules are approximately 1.08 metres wide. With a 400W output, the module achieves an efficiency of 21.3% with 120 one-third cells (such as Trina Vertex S).

KOSTAL’s compatibility with the new generation of 400W modules

KOSTAL inverters are already compatible with the new generation of 400W modules. The PLENTICORE plus, PIKO IQ, PIKO 12-20, PIKO MP plus and PIKO CI (see KOSTAL's list of solar inverters) are equipped to handle the larger module currents of up to 13 amps.

KOSTAL’s inverter range includes the right converter and control units for every installation that features solar modules of the new generation of 400W modules, from a small rooftop area to a larger ground-mounted system.

The importance of choosing the right inverter

With the new module cell sizes comes the importance of choosing the appropriate inverter. This is because larger but fewer cells on the roof mean a lower voltage per module, and at the same time, higher current movements, which the inverter must control and process with an optimal performance.

KOSTAL inverters already process the input current of the latest generation of modules with an output of 400 watts and more. This means that the entire module output can be used without the inverter having to limit the current flow.