hydro energia

“Reliability and performance are key factors in hydropower applications, therefore we have selected Marelli Motori as one of our preferred partner for installations where power density and technical know-how matter the most. Hydro Energia values partners that can provide cost-efficient, quality products as well as full support also after installation. We have chosen Marelli Motori as our supplier in this special project because of their deep understanding of hydropower requirements, their wide offering of customized solutions and in-house testing capabilities”.

Stefano Iorda, Hydro Energia Sales Manager


Hydro Energia is an Italian company with more than twenty-five years of experience in providing Water to Wire Solutions for the supply of Small Hydroelectric Power Plants.

The company is able to propose, with a proprietary know-how for the design and manufacturing, hydroelectric turbines (Kaplan, Francis and Pelton) from 100 kW up to 20 MW.


the challenge

Supply of generators for a brand new hydro power plant located in Albania. Design totally customized to fit customer’s requirements.

Total power supplied 18.600 kVA.

the solution

3 x MJHT 1250 M12
These are vertical generators specifically manufactured for hydro applications, the largest electrical machines ever produced by Marelli Motori at the time. 

Marelli Motori manufactures electric synchronous and asynchronous generators for hydro power plants which can be utilized in any turbine installation.


MJHT 1250 M12

Power 6200 kVA Cooling IC 21
Voltages 6000 V IP IP 23
Frame 1250 Enclosure ODP - Open Drip Proof
Pole 12 Main Application Pelton Turbine

innovative features

  • Special design of the rotor and stator air gaps, to allow the optimal cooling of the generator core in order to reach the requested output power 6.2 MVA

  • Special stator winding insulation system suitable for high voltage application up to 15kV, insulation class H, UL recognised, with good heat dissipation capability

  • IC 21 method of cooling, realised with two air outlets, specially designed for connection with the air ducts used in the plant

  • Special mechanical construction, in vertical position with special sleeve bearing for high external loads from the turbine

  • Special sleeve bearings suitable for biodegradable oil

  • Complete structural and modal analysis (for the vibration) by using dedicated calculation tool

  • Generator at low speed, high number of poles (12) independently mounted on the main rotor

  • Dedicated current and voltage transformers installed inside the special terminal box mounted on the generator frame