1. Electrical energy is inexhaustible.
True Its production does not necessarily depend
on the conversion of a fossil fuel: dams, wind turbines and photovoltaic cells all generate electricity by drawing
on unlimited energy sources.
2. It is not polluting.
True and False Although methods of generating it like thermal power plants
or nuclear power plants, which create radioactive waste,
may produce pollution.
3. In France, the price of electricity is indexed on the price of oil, even when it is produced with nuclear energy.
True Since the liberalisation of markets in Europe, electricity prices have been based on the inflationary prices of natural gas and oil.
4. There is no method for storing electricity.
True The mass/autonomy equation is as old as our mastery of electricity. Batteries are heavy and their efficiency
is low. Ultracapacitors deliver high levels of power, but over very short periods of time.
5. Electric motors are more efficient than thermal motors.
True The efficiency of a thermal motor (energy/mass displaced) is about 40%.
Sixty percent of the energy is dissipated as heat and friction. The efficiency of an electric motor used in rail transport
is between 95 and 98%.
6. Fuel cells are non-polluting.
True Provided that the method for producing
the hydrogen is non-polluting.
On the other hand, some climatologists are wondering about the effects of discharging large quantities of water into the atmosphere.
7. Fuel cells are as efficient as electric motors.
7. Fuel cells are as efficient as electric motors.
True At the present time, fuel cell efficiency regularly reaches 90 to 98% under certain experimental conditions.
8. A locomotive could run on solar energy.
False But the roof of
a locomotive could provide power for the lighting.
The efficiency of photovoltaic panels is about 100 W/m2.
9. Hybridisation means combining a maximum of two energy sources.
False For an electric-power vehicle, it is possible to combine solar panels + batteries + ultracapacitors + fuel cells + flywheels + …
10. Locomotives are equipped with catalytic converters.
False Research is being done, but the technology used on road vehicles is not directly applicable to locomotives.
11. The TGV is a big energy consumer.
False Per person transported, a TGV does not consume more than a small motorbike.
12. A speed of 360 km/h demands much more energy, proportionally, than a speed of 300 km/h.
True Power is proportional to the cube of the speed.
Going from 300 to 360 km/h will thus mean a 60% increase in the power requirement.
13. The TGV produces electricity.
True Using the electric engine as a generator during braking (referred to as recovery braking) produces electricity that can be sent back to the catenary. In the suburbs,
one train out of five runs thanks to the recovery braking of four others.
14. The train is the most economical transport mode in terms of energy consumption per person transported.
True On the Paris-Marseille route, consumption in kep1/ passenger is 32.2 for the airplane, 28.8 for the car, and 9.6 for the TGV.
15. How a train is driven can yield significant energy savings.
True In particular, by using the train’s kinetic energy, “economical driving” has long provided energy savings. Drivers are trained right from the start in this type e of driving.
16. Maximum energy efficiency has been reached for electric traction.
False Gains are still possible in urban operations with the hybridisation of energy sources (ultracapacitors, flywheels, etc.). For the TGVs, the margin is slimmer. New, permanent magnet motors developed by Alstom are a step in this direction.
17. New-energy consumption will be equivalent to 50% of fossil-energy consumption at SNCF within 10 years.
False The share of new energies will go on increasing, but it could not grow this large.
18. SNCF trains are already running on biofuels.
False Trials are under way with B6, a 6% biofuel. SNCF wants to begin testing B30
(30% biofuel) rapidly with the aim of having biofuels make up 10% of the consumption of
its diesel locomotive fleet.
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