Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hybrid Drives Make City Buses Cleaner

31.01.2011
City buses equipped with the new Siemens drive system Elfa, a combination of a diesel engine and electric motors, consume one-third less fuel than conventional buses.

Rather than powering the rear axle via an automatic transmission, as usually, the diesel engine in the Elfa system drives a generator that uses power electronics to supply electricity to one or more drive motors.


Around half of all local public transit trips in Germany are by bus. Like other heavy vehicles, however, buses are loud and produce emissions that are harmful to humans and the climate. The long-term solution is to use an all-electric drive. The problem is that today’s battery technology is relatively expensive.

Although in China, for example, there are already several buses powered by innovative lithium ion batteries. City buses make frequent stops for traffic lights and passengers, so they are well suited for use with a hybrid drive. This system marks an intermediate step on the road toward zero-emission buses powered either by batteries alone or a combination of batteries and a fuel cell system.

In the Elfa system from Siemens, the electric motors act as generators during braking and thus feed electricity back into the batteries. This power can then be subsequently used to drive the vehicle, which means at times the bus can run fully electrically and without producing any emissions. The vehicle range depends on battery capacity and can vary between a few hundred meters and several kilometers.

In combination with a clever power management system, Elfa not only reduces fuel consumption but also noise, since the diesel engine doesn’t provide acceleration and therefore operates only at quiet and economical engine speeds. As a result, fuel consumption falls by around one-third. On the basis of 60,000 kilometers a year, that corresponds to savings of around 10,000 liters of diesel, depending on the type of route driven.

Buses with Elfa drives are now being used in a number of cities worldwide, including a test fleet of double-deckers in London. Hamburg, meanwhile, is planning to introduce buses with an Elfa hybrid drive equipped with a fuel cell system rather than a diesel engine. This new drive technology is also ideal for other commercial vehicles that make frequent stops, such as garbage trucks or light delivery trucks. The Elfa system forms part of the Siemens environmental portfolio, which generated around €28 billion in sales for the company in fiscal year 2010.

Dr. Norbert Aschenbrenner | Siemens InnovationNews
Further information:
http://www.siemens.com/innovationnews

More articles from Power and Electrical Engineering:

nachricht Robot on demand: Mobile machining of aircraft components with high precision
06.12.2016 | Fraunhofer IFAM

nachricht IHP presents the fastest silicon-based transistor in the world
05.12.2016 | IHP - Leibniz-Institut für innovative Mikroelektronik

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Simple processing technique could cut cost of organic PV and wearable electronics

06.12.2016 | Materials Sciences

3-D printed kidney phantoms aid nuclear medicine dosing calibration

06.12.2016 | Medical Engineering

Robot on demand: Mobile machining of aircraft components with high precision

06.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>