Alstom will manufacture the transformers at its Mönchengladbach plant and expects to deliver them by late 2015.
The transformers will have a rated power of 350 MVA / 400 kV and 600 MVA / 400 kV.
The project will upgrade the substations in the German districts of Niederstedem, Urberach, Pfungstadt and Walsum.
Germany plans to phase out nuclear power plants by 2022, and achieve an energy mix with 50% of renewable energy sources by 2030.
Alstom said with less power plants, and new fluctuating renewable energy sources, electric networks are experiencing major challenges in stability and transmission capacity.
The Grid Development Plan of Germany requires the transformers to be added or replaced.
Amprion head of construction and operation Ludger Meier said: "Amprion will invest approximately €4.5 billion in its high voltage grid by 2023.
"The feed-in of renewable energies requires additional transformers to exchange the power between the distribution and transmission grid, and the transport of the up to 400 tonne large power transformers calls for an intact infrastructure, especially stable bridges."
Alstom Deutschland board member and Alstom Grid general manager in Mönchengladbach Jochen Schwarz said: "Our power transformers from Mönchengladbach will contribute to the continuous expansion of the power grids, and to the implementation of the energy transition in Germany."
