Ricardo delivers energy usage calculations on forthcoming Paris Metro routes

The internationally operating engineering consultancy company Ricardo Rail has produced the energy usage estimates for rail operations on three forthcoming lines on the Paris Metro. This allows Public Transport Operator Keolis to anticipate future operating costs and identify opportunities for efficiencies.

Lines 16, 17 and 18 will form part of Grand Paris Express, a new network of rapid transit routes encircling the French capital allowing passengers to travel from suburb to suburb without having to pass through the central district. Line 16 will serve ten new stations on a 27km route through Paris’ eastern neighbourhoods; Line 17
will extend for 16km to the northeast of the city, serving nine stations including Charles De Gaulle airport; Line 18 will serve 10 stations on a 33 km route from Aéroport d’Orly to Versailles-Chantiers.

The operation of this fully automatic metro will open to passengers in the second half of 2026. Routes 16 and 17 will connect to the Saint-Denis–Pleyel station which opened in June 2024 to serve the nearby Stade de France where much of the 2024 Summer Olympic Games takes place. The station will be key to the Paris 2024 Olympics and Paralympics and a major interchange for the Grand Paris Express network.

During the competitive process to select the concession holder for Lines 16, 17 and 18, public transport operator Keolis sought to include accurate energy usage calculations in their submission, and also highlight where they could introduce energy efficiency measures without impacting on the required service levels.

Ricardo’s team was appointed by Keolis to perform the calculations that would extend across not only the traction energy (with both lines operating on a 1500Vdc network), but also the energy for the sub systems such as the onboard heating, lighting, ventilation and cooling.

Johan van der Werf, Ricardo’s Principal Technical Consultant explains that the calculations had to take into account a wide range of factors specific to each route, from the fluctuations in passenger numbers throughout the day to the impact of slopes, curves and tunnels. “To begin our assessments, we developed a digital model of each line, simulating the infrastructure and driving profile of the routes”, says Van der Werf. “We used that to calculate the energy use between two stops, assessing likely acceleration and braking movements, for example, as well as the energy used at dwell points when the vehicle is standing still.”

“The work is partly based on previous energy use calculations we have performed for the Dutch operators. Over the years, we have developed robust methodologies for modelling the interactions between rolling stock, infrastructure and control systems. It is never a case of repeating past assignments. Each line has a unique operational environment with: speedprofiles, slopes, tunnels, et cetera.”

Efficient driving techniques

The project was also an opportunity to provide projections on how energy usage could be managed by Keolis during daily operations. “Our models allow us to test a range of variables. For example, by comparing different timetables we could pinpoint where efficient driving techniques could contribute towards reduced energy use. These might include coasting (where the train shuts off traction as it approaches the station to reach it with as less as possible braking) or marking locations on the route where speed limits could be used without impacting on service capacity.”

“The value we bring lies in our experience of taking into account the multiple factors that can distort
the accuracy of the calculations”, Van der Werf continues. “It’s a complex task. But our calculations are based on the deep knowledge of rolling stock and energy consumption that we have assembled over several decades. We know which parameters from rolling stock, infrastructure and operation influence energy consumption and where certain
measures can secure energy efficiencies.”

Île-de-France Mobilités subsequently awarded Keolis the contract to operate metro lines 16, 17 and 18, with passenger services anticipated to start on the lines in 2026. The seven-year contract for lines 16 and 17 also includes the operation of Saint-Denis Pleyel station which, from summer 2024, will play an integral role in the 2024 Olympics and Paralympics, serving both the main athletics and aquatic centers as well the athletes’ Olympic Village.