While road-based vehicles (cars, trucks) by their vast numbers are the most significant contributors to pollution, it shouldn’t be forgotten that others forms of transport – namely boats, planes and trains – also play dirty. Nor are they hopeless polluters. Because they are commercially operated, they are amenable to improvements that save money or avoid regulation. So just imagine how efficient a train could be if it were powered like a Toyota Prius.
It’s happening. In Japan, of course, where else? Germany. Engineers in both countries looked at the concept behind the Prius – using an electronic control system to balance the output from a battery-driven engine with an internal combustion engine – to power locomotives. Like the Prius, applying the brakes converts kinetic energy into electricity for the battery. This is called regenerative energy. Imagine how much energy a mile long coal train generates when it brakes.
Hybrid trains are not exactly new; the first one was built in what was then Czechoslovakia (Czech Republic) in 1986. It was a fully operational model and worked the rails for ten years, however the resources for battery production were not available in the Soviet system and mass production was never started. Japan had the first production version, a hydrogen powered engine with a lithium battery built by JR East in 2007. Alstom transport division in Germany is the first production model to have batteries as the prime engine with the diesel powered engine as a backup. In the United States, General Electric (GE) has demonstrated its Evolution Hybrid Locomotive, which uses sodium metal halide batteries.
Batteries continue to be the problematic part of the technology (as it is for cars). The duty-cycle of batteries (most have limited range and last only a decade or so) currently limits hybrid trains to uses where short distances and frequent braking help keep the batteries charged. This means in practice most hybrid locomotives are used for freight-yard switching. Economically this has been a problem since many train operators don’t buy new yard locomotives; they cycle their older long-distance locomotives for the job.
Nevertheless as the technology improves the appeal of saving between 10 and 30 percent on fuel costs, running quieter engines, and meeting stricter environmental laws (as in the European Union and North America) moves the rail industry in the direction of hybrid locomotives.