¡Back the trolley bus! Well, not exactly. In several cities of the world are still in service lines electrified buses, which are a mixture of trams and buses conventional. The novelty in this case is that it is a via electrified extraurbana, and serves to hybrid trucks of the Scania brand.
E16 of Sweden, near the town of Gävle, has two kilometres of electrical cables suspended. The project is a public-private partnership that has an investment of approximately € 8 million to test a broker electric, with the collaboration of Scania and Siemens.
The nordic country aspires to have a free mobility of carbon emissions for the year 2030, and that includes heavy vehicles such as trucks. Thanks to this project we can test the viability of the system, and see if it turns out to profitable to economical and ecological effects.
The cables have electrical current 700 volts, that is not a number very far-fetched. Ride the route trucks Scania G 360 with two-wheel drive, and a weight of 9 tons. The internal combustion engine is a 9 liter capacity, with 360 horsepower, which works with bioethanol. The electrical part that delivers 177 HP and a maximum torque of 1,050 Nm. Here what counts is the torque.
While traversing the route electrified, a pantograph on top, captures the energy. The driver can retire when you want, as to make an overtaking, without having to add just the complexity of the driving. A the lithium battery of 5 kWh have enough energy to walk 3 miles without the need to turn on the main engine, and so continue rolling in electric-only mode.
At the technical level, we speak of a hybrid in parallel, the two motors are connected to the transmission and work at the same time, or just the electrical part. While do not turn the combustion engine, the local emissions are nil. Outside of the electrical pathway, the truck pollutes less than using diesel fuel, since the ethanol is supposed to free carbon net (because the production is captured from the atmosphere) and does not emit particles.
electric mobility has a huge environmental benefit, but has the problem of storage. The batteries are expensive, bulky and heavy, and store little energy in relation to deposits of liquid fuel (low energy density). In addition, recharging is a process that is not as fast as would be desirable.
Another possibility would be the constant delivery of energy, that is to say, that the pathway to provide the current. There are three modes:
- Lanes electrified: version 1:1 of the well-known “Scalextric”, which requires vehicles to follow an exact layout
Charging by induction: the energy is transmitted from the asphalt to the vehicle by waves
Routes electrified: a few cables on the road are to provide energy, as occurs in the ferrocarri. It seems the least expensive solution
we Talk about the third solution, only found at such a height that makes it difficult to use by passenger cars. This solution is more reasonable for heavy-duty vehicles, because they are the most polluting and most energy-consuming, given their high weight and poor aerodynamics.
The implementation of the routes electrified for heavy-duty vehicles represents a remarkable reversal, but it can be interesting in economic terms if the savings in fuel is relevant. A truck or bus to 90-100 km/h can consume quietly 30-40 l/100 km of diesel. For this particular case, a constant delivery of 130 kW, in fee tip (the worst case), assumes in electricity a saving of around 50%.
In other words, the carrier can be cost-effective to pay one-half in power, even if you later have to provide a toll or fee for the maintenance of the line. With that the saving is 25% since we are talking about thousands of euros per year. The system has to be sustainable, both to the carrier and to the transmission line.
The environmental benefits are clear, is eliminated of a stroke the contamination in these sections, and if the trucks are hybrids, they can move in ways not electrified paying the same as always. This technology has more potential for use in the busiest roads by trucks, as it could be the M-40 madrid, or the environment of large industrial estates. With the passage of years may see greater deployment of this technology, which is now in the experimental phase.