GREEN TRANSPORT:Scientists in South Korea claim to have found the key to a low-carbon future with an 'online' public transport scheme that runs on underground electrical cables
GIVEN THE painful birth pangs of the Luas, can anyone imagine Dublin scrapping its choking diesel buses and replacing them with a whispering fleet of electric vehicles? The capital only launched its first hybrid bus between Rathfarnham and Dublin Airport last December, a precursor to an "enormous process of change" to the city's transport network, promised Transport Minister Noel Dempsey.
While Dubliners wait for the fulfilment of that ambitious pledge, however, South Korea may already be several streets ahead. Seoul city is negotiating with the nation's top science university to build a network of buses powered by an all-electric system. If it gets the green light, the project's designers claim it will transform public transport not just in the South Korean capital of 10 million people - but across the planet.
Well, they would say that, but how does it work? Most all-electric and hybrid systems, including the Dublin experiment, rely heavily on rechargeable Lithium-ion batteries, which are replaced every few years. Bulky and costly, the batteries must also be constantly topped up at recharging stations along the route, or swopped for fully recharged standbys - Beijing experimented with that laborious technique at the Olympics last year to allow its 50 electric buses to run all night.
For all their problems, however, lithium-ion batteries are still widely seen as a crucial component of the green economy, an approach that "just doesn't make sense", according to Nam Pyo Suh, president of the Korea Institute of Science and Technology (KAIST), which developed the experimental bus.
"The batteries are heavy and expensive - making a $20,000 car cost $40,000," he told The Irish Times. "And lithium is finite - there is only 10 million tons available worldwide."
KAIST's On-Line Electric Vehicle gets around these problems by putting the power source underground. An electric cable buried 5cm beneath the road generates a magnetic field read by pick-up coils beneath the bus and then converted back into power inside.
When the vehicle moves "offline" - or away from the power grid, a small standard car battery concealed in the roof - one-fifth the size of the Dublin bus version - keeps the engine ticking over for up to 10km. No need for diesel, recharging stations or those lithium-ion monsters, explains the vehicle's project leader Chun-Taek Rim. "We've been trying to solve this battery problem for 30 years. We think we have cracked it."
Among the hundreds of customers who have lined up for a demonstration of this potential technological marvel at KAIST in Daejeon City, is Korea's President Lee Myung-bak. Lee was so impressed when he visited in February that he gave the project $25 million (€17 million) in seed money - not bad in the middle of a recession. Trials in Seoul and in at least one other Korean city are set to begin this year. If all goes well, the capital's entire fleet could be transformed within a decade.
The questions pile up, however, as soon the hyperbole stops. For one thing, who is going to pay for the huge cost of digging up all those busy roads to lay the cable? Where is all the extra power going to come from? And if the solution was this simple to begin with, why hasn't anyone come up with it before?
As critics have pointed out, versions of the online vehicle have been around for at least 30 years. Berkeley University in California experimented with what it called "dual mode electric transportation" before the project was scrapped, mainly due to the cost of laying the system's heavy iron and copper cables. Opponents also pondered the health impact on anyone sitting above those 50Hz magnetic fields.
Project leader Rim claims that KAIST has overcome the Californian system's limitations with what he calls an "innovative configuration" of cable materials, and extra computing power to maximise pick-up and output - intellectual property concerns prevent him from discussing the details.
As for laying cable, "the correct comparison is with recharging stations," he says, pointing out that many cities are already building recharging networks. The relatively shallow depth of the cable means that it can be laid very quickly - at one-third the cost of any comparable system.
As for where all this power is going to come from, that's easy - from one of South Korea's 20 nuclear reactors. For Koreans queasy about the prospect of entrusting the future of public transport to nuclear power, KAIST has the perfect retort: less oil. Converting half of the six million vehicles on the country's roads to the new system would slash $3 billion a year in oil imports. And there are other bonuses: 42,000 new jobs by 2012, and the chance of cornering a world-beating technology well ahead of the pack.
Of course, the low-carbon future might just as easily belong to the No 16 from Rathfarnham, chugging along on its 2.4-litre diesel engine and Lithium-ion powered Siemens hybrid drive - though it seems unlikely.
Whatever happens, the haste to push Seoul's online bus into service is another sign that engineers the world over are now - finally - firmly in the race against runaway climate change.
