Emission-free shore power for ships.

A safe haven for our environment: Mechanical rotary frequency converter (MRFC)

Environmental protection is an issue that concerns us all, and we at Stolze GmbH are also doing our bit to significantly reduce pollution in port cities. This is because in order to minimise NOx and CO2 emissions in ports, ships require an alternative and environmentally friendly supply of shore power. The challenge here, however, is that most ships and cruise liners worldwide have 60 Hz on-board power supply systems, and in European ports in particular there are problems in providing a sufficient supply of shore power at 60 Hz. And this is where we at Stolze GmbH come into play with our container-based shore power systems.

Maritime solutions for a clean environment.

Shore power supply with MRFC

Different applications exist, such as via medium-voltage/low-voltage converters with converter transformers or gas engine generator sets that are operated using LNG to facilitate shore power supply for ships. A rotating frequency converter (MRFC) constitutes a much more cost-effective, robust and individual variant here that can be implemented in combination with a wide variety of electrical machines. This conversion technology has already proved itself to be very successful in maritime applications for decades and without high operating costs in the low and medium voltage range.

In order to generate a stable and resilient 60 Hz on-board power supply in the low and medium voltage range, we at Stolze GmbH decided to use two synchronous machines with different numbers of pole pairs here due to the special properties of the synchronous machines and the corresponding requirements of the marine grids.

Advantages of shore power supply using MRFC:

  • Low acquisition and operating costs
  • Mobile units (containerisierte Systeme)) can be realised at almost any location without large investments (can be set up flexibly in terms of the location)
  • Flexible adaptation to the local conditions.
  • Outstanding electrical properties and the often neglected situation onboard ships, such as high inrush currents of leakage and fire pumps in the event of fires, which have to be switched on in case of problems at the port
  • High transient load capacity of the synchronous machines used here
  • The MRFC requires little to no complex electronic converter technology, i.e. applications can be realised here that cope completely without power electronics.

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Green Energy for shipping!

Are you looking for a sustainable solution for green shore power at the port? Our innovative shore power supply and shore power systems sustainably reduce nitrogen oxide emissions while focusing on long-term solutions in the form of container-based MRFC solutions that make use of renewable energies and green, electrical power. This is because electricity generated in this way provides an environmentally friendly solution for shore power in every port and assists companies in the energy transition process. Do you require more information or specific advice concerning our green technology, shore power systems and shore power supply? If you do then we look forward to hearing from you without obligation.


Our home port

Stolze GmbH
Schwertfegerstraße 12
23556 Lübeck
T: 0451 890 02-0
F: 0451 890 02-899