Inverters

Solar inverters are an important part of a solar system. in our online shop, you will find a large selection of different solar inverters for your PV system.

Please also note that due to the high demand, the delivery times are currently a little longer (10-20 days).

Showing 1–9 of 13 results

Which inverter is the best?

Solar cells produce direct current due to the system. So-called inverters are required to convert solar power into usable alternating current. But not all inverters are the same. There are models with and without a transformer, module inverters, stand-alone inverters, and a few more. We explain the differences, name advantages, and disadvantages, and make recommendations.

Basically, inverters have to be distinguished according to whether they are components of a grid-connected photovoltaic system or an island system. Depending on whether there is a connection to the mains or not, the converter works slightly differently:

solar inverter how it works

Inverters for grid-connected photovoltaic systems

In a grid-connected PV system, the inverter is located between the solar module(s) and the electricity meter or between the solar module and consumer or, if applicable, the electricity storage device.

To feed into the power grid, the inverter must have an AC voltage that is identical to that of the grid. These so-called grid feed-in inverters must be approved by the grid operators. In general, small systems with an output of up to approx. 5 kW usually feeds in the electricity in one phase, and larger systems in three phases. Knowledge of the voltage converter, the device types, and the design helps when selecting the right inverter.

Transformer inverter or transformerless inverter?

Transformer inverters have long been considered the safest. Correct: The transformer provides galvanic isolation, which protects the inverter and thus the entire photovoltaic system from serious damage in the event of overvoltage. On the other hand, this also creates conversion losses, which are usually reflected in lower efficiency. The heavy transformer devices can be connected to both positively and negatively grounded solar modules. This can be crucial when installing thin-film modules.

Transformerless inverters achieve significantly higher efficiencies because the input and output sides are electrically connected. They are also lighter and therefore easier to install. Further plus points: Fanless inverters run more quietly and are cheaper to produce. Crystalline modules do not require grounding and can therefore always be operated with an inverter without a transformer. Care must be taken with thin-film modules.

Conclusion: Due to the better efficiency (approx. 98% vs. 95%), the lower operating noise, and the lower purchase price, transformerless devices have prevailed. In order to provide adequate protection against overvoltages, they must be installed in accordance with protection class II.

Inverter types

Depending on the size of the system, four device types can be considered:

  • Module inverters for small systems: With this design, each solar module has its own inverter. The disadvantage: if the system consists of several modules, a corresponding number of devices are required; As a result, disruptions occur more frequently. The advantage: If the individual modules are aligned differently and shaded, the system can be optimized most easily with module inverters.
    Module inverters are made for the increasingly popular mini solar systems, also known as plug-in solar devices.
  • String inverters for small to medium-sized systems: If several modules are connected in series, the power losses with module inverters would be too great. On the way out one inverter for the entire string. With several strings, several string inverters are also necessary. The disadvantage in unfavorable conditions: Since the solar cells influence each other, the performance of all connected cells drops. String inverters are the most commonly used inverter types.
  • Multi-string inverters for medium-sized systems: Instead of connecting each string to a single-string inverter, multiple strings can also lead to a multi-string inverter. This is an inexpensive solution for medium-sized systems with modules connected in parallel. Recommended for PV systems with different orientations and the associated delayed yield.
  • Central inverters for large systems (from approx. 100 kW): In large systems such as solar parks, a large number of multi-string inverters would simply be too expensive to purchase, install and maintain. This is why large devices are used here, so-called central inverters. Since they are out of the question for users of conventional roof systems, they are only mentioned here for the sake of completeness. However, the purchase can be worthwhile for photovoltaic systems in agriculture or in industry and commerce. A solar installer can assess the cost advantages.

Shopping Cart
×
Bought Recently