Solar modules with over 21 % efficiency - a wide variety for maximum solar yields

Solar modules with high efficiency are crucial for the optimal use of solar energy. We offer a wide selection of modules with over 21 % efficiency - including monofacial, bifacial and full black modules for different requirements.

Various cell technologies are used, such as p-doped, n-doped and heterojunction cells. N-doped half-cell modules in particular are considered to be powerful and economical.
The range includes modules from leading manufacturers such as JA Solar, Jinko Solar and Trina Solar with outputs of up to 660 W. This variety enables tailor-made solutions for commercial and private photovoltaic projects.
You can use the filter options on our platform to quickly find the right solar module - tailored to the output, cell type, color variant and other technical features.
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PV modules with high efficiency - technology at a glance

Highly efficient PV modules enable optimum use of roof or open spaces. With an efficiency of over 21 %, they are among the most powerful solutions on the market. But how is this efficiency measured - and what factors influence it?

How is the efficiency of a solar cell determined?

The efficiency of a module indicates how much of the irradiated solar energy is converted into electricity. It is measured under so-called standard test conditions (STC) in order to be able to objectively compare different products:
  • Irradiation: a "flasher" is used to simulate a radiant power of 1,000 W/m².
  • Temperature: The ambient temperature is kept constant at 25 °C.
  • Light spectrum: The natural sunlight is precisely simulated.
The electrical output of a module is calculated from the product of current and voltage at the maximum power point (Pmpp). The efficiency is then calculated from the ratio of Pmpp to the irradiated energy on the module surface.
Manufacturers often document the measurement results of individual modules in flash lists, which play an important role in logistics and quality assurance. The measured values can be clearly assigned using serial numbers.

The influence of efficiency on the efficiency of solar cells

The development of solar cells is characterized by innovations aimed at higher efficiency and better long-term stability. The following technologies currently dominate the market:
  1. Crystalline silicon (c-Si):
    The basic technology behind almost all of today's PV modules. It forms the basis for modern cell concepts such as TOPCon, PERC and HJT - with market shares of over 90 %.

  2. TOPCon cells (Tunnel Oxide Passivated Contact):
    This technology established itself in 2024/2025 as the successor to the PERC cell. TOPCon modules achieve efficiencies of up to 26 % and offer higher output at similar production costs thanks to optimized rear contacts.

  3. HJT (heterojunction) cells:
    Combine crystalline and amorphous silicon layers. They are characterized by high efficiency, low temperature losses and good low-light performance. HJT is gaining ground in the premium segment in particular, but with higher production costs.

  4. PERC cells (Passivated Emitter Rear Cell):
    Long the standard for monocrystalline cells, now increasingly replaced by TOPCon. PERC modules with efficiencies of up to 24.5 % are still in use, particularly in price-optimized projects.

Natural efficiency limits and technological advances

The maximum possible efficiencies of solar cells are limited by the physical properties of the materials:
  • Crystalline silicon (c-Si):
    The theoretical upper limit is around 26.7 % (Shockley-Queisser limit). Today, modern cells such as TOPCon and HJT achieve efficiencies of up to 26 % on an industrial scale.
  • Gallium arsenide (GaAs):
    Achieves laboratory efficiencies of up to 29-30 %, is mainly used for special applications.
  • Cadmium telluride (CdTe):
    Thin-film cells with efficiency limits of around 22-23 %.
  • Perovskite cells:
    Rapid progress with laboratory efficiencies of over 25 %; tandem cells made of perovskite and silicon already exceed 30 %.
Technical developments, particularly in TOPCon, HJT and tandem cells, are helping to get ever closer to these limits and significantly increase the efficiency of solar modules.

What influences the actual performance during operation?

In addition to cell technology, various environmental factors have a major influence on the actual energy yield of solar modules:
  • Temperature:
    The efficiency decreases as the module temperature rises. The temperature coefficient is typically between -0.3 % and -0.5 % per °C, which means that the output decreases with heat.
  • Irradiation conditions:
    Under diffuse light, such as cloudy conditions, high-quality modules with good low-light performance achieve better results than standard modules.
  • Performance Ratio (PR):
    This value summarizes real losses - such as soiling, partial shading, alignment or cable losses - and is crucial for practical system planning and yield forecasts.

Why choose high-efficiency PV modules?

High-efficiency PV modules offer decisive advantages - both on confined roof areas and in large-scale systems:
  • More power per square meter: ideal where space is limited
  • Faster amortization: higher energy yields shorten the investment period
  • Efficient space management: fewer modules mean lower installation and material costs
  • Technological future-proofing: current cell technologies remain competitive for longer
  • Contribution to the energy transition: higher yields mean more sustainability for the same area
The choice of modern high-performance modules not only increases the efficiency of a system, but also improves its cost-effectiveness and environmental balance in the long term. With every further development in cell technology, solar energy becomes more efficient, more reliable and more future-oriented.

Module variants at a glance

In addition to the cell technology, the design of the modules also plays a role - both visually and functionally:
  • All black modules:
    Completely black, discreet appearance - particularly popular in residential buildings or for visible installations.
  • Bifacial modules:
    Capture light on the front and back. This enables up to 20 % more yield, ideal for ground-mounted systems with reflective surfaces.

Find out more about inverters and storage solutions for your project.