We talked about the history of streetcars in Seoul and that Korea is developing a new type of public transport method, which merges the advantages of streetcars and buses. The dependence on fossil fuels has to be reduced. The solution are electrically powered vehicles. Electric vehicles could get energy through external connections (like overhead wire) or they have to carry a battery with a high capacity. Even though overhead wires are still very common in Europe, Korea seems to prefer batteries.
That makes the development very challenging and creative solutions have to be found. In Korea, a company seemed to found such a solution, which involves changing batteries instead of recharging them directly inside of the vehicle.
The e-bus at Namsan is already a example of public transport with electric batteries but they only operate on a short route. Ministry of Land, Transport and Infrastructure (MOLIT) built up a test rail track, which is 1 km long (so they have to drive up and down the whole time), with the purpose to test batteries in operation. Currently, the battery of the tram is strong enough to run for 25 km. That’s roughly the distance a blue bus drives into one direction throughout Seoul. However we shouldn’t forget that a bus halts and accelerates thousands of times on the route, drives a hill up and waits at a red light. Here’s a video from the opening of the test track in last year:
Constraints of battery power is a hot issue in the transport industry. The US government expanded investments for research and development of battery capacity:
On the transportation side, radical advances in battery technology are needed to build vehicles that go further on a gallon of gas — or on their charge. Through interdisciplinary research and development, the Hub is looking to accelerate the technologies that will increase power capacities and charges, and ways to ramp up manufacturing this technology to full scale quickly.
The problem hereby is that batteries can’t be developed any further if we keep the current chemistry. So development requires completely new technology and chemical composition, which is under our current view point very expensive.
Don’t Recharge Batteries, Exchange them
So, until we have five time stronger batteries which are five times cheaper than today, how could we let electric trams and buses operate? The answer in Korea is simple: battery swap during operation! Like we are used it with batteries of a remote controller: If they are empty, take them out and put new ones into the remote controller. While you are using the new ones, the old batteries can be recharged. This concept is developed in Korea by the Smart e-Bus company and in their brochures they call the invention “the world 1st automatic battery swapping e-bus system”. According to their homepage the exchange of a battery is going to take 30 seconds and it works like this:
Smart e-Bus believes that a bus can drive 20 km with one battery charge. They plan to have the battery swap at the garage or at the end of line. Just in emergency cases, when the energy status of the bus is low, they will change the batteries at specific stations along the route. This concept could be used for trams in the same way. I’m not sure if they are able to install this system successfully but at first, we need better and cheaper batteries. Then this system can be tested on commercial routes.