SNCF: TTG Energymiser

Published February 28, 2020 in Article

SNCF operates the country’s national rail services—for both passengers and freight— including the TGV, France’s intercity high-speed rail network.

SNCF (Société Nationale des Chemins de fer Français or “French National Railway Company”) is France’s national state-owned railway company. SNCF operates the country’s national rail services—for both passengers and freight— including the TGV, France’s intercity high-speed rail network.

SNCF also direct the maintenance and signalling of rail infrastructure owned by Réseau Ferré de France (RFF).

The railway network consists of about 32,000 km of route, of which 1,800 km are high-speed lines and 14,500 km electrified. Around 14,000 trains operate daily.


On June 20, SNCF was named Company of the Year during the forum Energy Time – the annual gathering of decision makers in the field of energy – for its Opti-TGV highspeed train.

Of the achievement, Director of Energy at SNCF, Olivier Menuet said, “It is a great pride for the teams of SNCF Voyages and the whole group.”

This project was born from innovative SNCF Voyages, and it’s success has now reached the Direction of Energy and Traction at SNCF level.


Opti-driving is a software program that saves energy by recommending to TGV drivers an ideal speed according to the geographical position of the train.

Firstly, the route of the line is recorded in the software. Next, this data is used to continuously calculate and recalculate the optimum train speed. This allows for smooth acceleration and braking, and of course, a more seamless experience.

Olivier Menuet reinforces the functionality. “Agents already optimise driving in order to reduce energy expenditure, but the software makes it possible to go even further in this direction.”


Opti-Conduite aims to reduce the energy consumption of traction trains by 5 to 10%. The rationale behind this is two-pronged.

Firstly, it serves an ecological purpose, with lower energy expenditure logically diluting stress upon on the environment.

Secondly, it serves a financial purpose. Expenditure directly related to TGV trains is around € 200 million per year (on an overall energy budget of €1.3 billion per year for SNCF). This compares with €220 million per year spent by SNCF Voyages in the past.

There is also an important advantage in terms of maintenance and lifespan of high-speed trains, as braking and acceleration significantly affects the equipment (too much using cruise control affect the equipment and giving a speed reference with Opti-Conduct “allows to use less cruise control”).


Opti-Conduite was tested across 2016, and deployed since early 2017 and today, the software is used on all TGV axes. Elsewhere, intercity, Transilien, TER and Freight have expressed interest in adopting the system. The consensus seems firmly in favour of maximising the longevity of these trains and their associated equipment.


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