My brother just wrote an interesting post about hybrid cars saying how the current measures for economy we see aren’t really effective.

He has a good point, but also what worries me about hybrid vehicles is the environmental impact of them over their life-cycle. Most hybrid vehicles have batteries, these batteries are often made with toxic chemicals and heavy metals. How long do the batteries last? What happens with them when they are expired? I know my laptop battery, after two years of heavy use, is now at half its’ capabilities so how long will the very expensive batteries in a hybrid vehicle last?

Apparently if the KERS (Kinetic Energy Recovery Systems) used in F1 was applied to London Underground they would use 50% less electricity, but like in hybrid cars where would this charge get stored? Certainly not with conventional batteries because they can’t absorb charge quickly enough and have trouble with the discharge power for fast acceleration; that said Altairnano and Hitachi both claim dramatic improvements in this area. Super capacitors suffer leakage so this wouldn’t be very efficient for a standing vehicle. One of the most effective stores of energy is actually mechanical storage because conversion losses can be reduced substantially and this would be the best solution for London Underground. Fit a large spinning mass under the train and store the energy recovered in breaking deceleration directly on the mass, then couple the mass to the drive train during acceleration to give it that extra boost.

However, we can’t all carry round a huge mass in our cars because it will have a worse affect on the efficiency of a car compared to the constant stop-start of the Underground train.

Some new technology is needed and I don’t know where it will come from but, like mechanical storage, I think we will be surprised and it will come from the past!

The London Black Cab, or Hackney Carriage (as they may not always be black) is one of the most iconic symbols of London. This Christmas I was asked by Angeliki’s brother-in-law what company made them (what brand). Oddly enough no one company makes all of them, unlike in cities like Berlin where almost every (yellow) taxi is a Mercedes, the Hackney Carriage is infact a style of vehicle which has been around since the 40s. From Austin, LTI or Metrocab. The most notable thing about the Hackney Carriage is that it has a 25ft turning circle which allows it to turn around in London’s tight streets in one go, I doubt a New York Taxi could achieve such a feat!

London’s Hackney Carrage drivers are the only ones allowed to stop and ply for trade on the streets of London without a booking, so if visiting London only ever hail a black cab otherwise you might not be so safe. The other advantage of a licensed London Cab driver is that he must has passed “The Knowledge”, which is a test which is designed to ensure that the applicant knows every part of London inside and out. They are tested to ensure they can (without the assistance of a map) remember a selection of routes around London and the location of almost any street.

Read more about this fascinating vehicle here: