University of Central Florida Researchers Verify Aspects of Planar Energy’s Solid-state Battery Approach; Potential for Half the Cost and Triple the Energy Density of Current Li-ion Cells
Petrobras Doubling Production Capacity of Candeias Biodiesel Plant

Madrid Planning to Ban New Taxis and Buses Running on Diesel

NGVA Europe. Alberto Ruiz-Gallardón, Mayor of Madrid (Spain) announced last week during an informative breakfast meeting in Madrid that the City Council of Madrid is preparing a regulation that will prevent the purchase of new taxis and urban buses running on diesel.

This decision was taken because diesel models emit too much NO2. Madrid is the first European city that acts against Diesel technology for environmental reasons. The municipality will not force to buy any special technology, but will establish a control not only in terms of CO2 but also regarding the NO2 emissions.

This news is going in line with a recent announcement made for by Pedro Calvo, Delegado de Seguridad y Movilidad del Ayuntamiento de Madrid (delegate for security and mobility of the Madrid municipality) and President of EMT Madrid, who said that out of the 60 new buses already ordered for 2010, 80% will be CNG vehicles. The rest will only be Diesel, because there are no CNG versions in some specific configurations available.



Fuel Cell or Electric or many Hybrid configurations could do much better than Diesel buses and taxis.

Banning vehicles (in city centers) above an established known pollution emission level may be one of the most efficient way to get cleaner air while promoting the purchase and use of cleaner vehicles.

If 100+ other major cities would do the same, it could make a difference and start the ball rolling in favour of cleaner vehicles.


Weird. Most of the new diesels have greatly reduced NO2 emissions. Plus why wouldn't they support biodiesel as an option? So instead of getting new cleaner diesels, they stick with the old polluting ones. Great thinking!


There was a story about electric Jeepnys. After the war the islanders turned Jeeps into shuttles. Many of them had diesels that would pollute in stop and go traffic. One person proposed an electric one with fiberglass body that weighed less than 1000 pounds. Since they were just used in the city at slow speeds, this proved to be a very effective transportation method.

The Goracle


Rather than take a GIANT step backward by banning diesel engines - engines that are 30% more thermodynamically efficient than gas engines, require the fleets to run on 100% Biodiesel. Phase it in over the next X years.



Even newer diesels are much "dirtier" than gasoline engines. All the complicated after treatments to reduce the cancer causing particulates in addition to NOx problems make diesels expensive. Even with all the extra filters and urea they pollute so much that they are very unattractive in dense urban areas where people have to breath. The new small displacement direct injection gasoline engines with turbos are probably going to displace diesels for both cost and pollution reasons.



Is biodiesel realy cleaner when all inputs and resources used to make it is factored in?

Diesel engines may be 25% more efficient per fuel volume but since diesel fuel has 24% more energy per volume than gasoline, the NET difference in energy efficiency is almost NIL.

None of the ICE are very efficient when compared with e-motors. The average difference is still about 3x in favour of e-motors.

Roger Pham

Diesel engines modified for use with NG can retain the same thermal efficiency as with diesel fuel. The high-compression-ratio engine can be powered by NG for the most part, with ignition by a small spray of diesel fuel. This allows the engine to retain the high thermal efficiency as with 100% diesel fuel, with the ability to be a dual-fuel engine, just in case a CNG station is not available. See this link:


The latest OE NG aquisitions for Sydney,Aust's buses add to the existing NG fleet.
Unfortunately they bought twice as many diesels on that order. I think price was an issue.
Otherwise the central servicing and fueling infrastructure is a factor.
The NG bus emissions are of course the cleanest emitters available and are not unpleasant to the nose.
The greatest population concentration and passenger miles as well as competent fleet workshop services are the logical place to get the best value on investment.
No - brainer.


The Goracle


Diesel engines may be 25% more efficient per fuel volume but since diesel fuel has 24% more energy per volume than gasoline, the NET difference in energy efficiency is almost NIL.

I don't think that you added correctly. If diesel fuel has 25% more energy per volume, and the thermodynamic efficiency of diesel engines are 30% more efficient than gas engines (due mostly to compression - see your Thermodynamics text book for proof), diesel engines are even that much more efficient than gas engines. You don't subtract the two numbers.

Biodiesel greatly reduces the pollutants as well.


Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)