An extensive study on the environmental impact of Swissmetro has been conducted by the National Research Programme 41 in Switzerland (Ernst, Geisel et al. 2000). Concerning energy consumption the study yielded the following results:

Comparison Swissmetro – Air traffic

On an assumed pilot route Frankfurt-Rome, the primary energy consumption per person kilometer of Swissmetro would be 5 to 10 times less than in air traffic. The exact factor depends both on actual passenger numbers for the Swissmetro and on the efficiency gains in air transportation (that could be as high as 50% in the next 50 years according to some experts). This assessment includes the so called "grey energy" needed to construct the infrastructure. The (electric) energy demand for operation only was calculated to be

0,185 MJ/pkm for an assumed 76.000 passengers/day

0,21 MJ/pkm for an assumed 38.000 passengers/day

Comparison Swissmetro – conventional high speed rail systems

The energy consumption (for operation only) of the Swissmetro would be roughly 50 % less than both in conventional high-speed rail systems (e.g. ICE) and in ground-level Maglev/Transrapid system. This comparison refers to equal speeds.

Influencing factors

The following factors are especially relevant for energy demand of a Swissmetro system:

• Tunnel width: The wider the tunnel tube, the less air drag is encountered by Siwssmetro vehicle. Even if the additional energy for tunnel excavation is included in the calculation, a wider tunnel profile is favourable for energy efficiency
• Degree of evacuation: The less air pressure, the less air drag in the tube. There is however an evacuation limit given by safety considerations.