Thursday, 18 December 2008

Top Gear's misrepresentation of Hydrogen Verses Battery Electric Cars

I'm referring to the most recent Top Gear - Series 12, episode 7, [previously] viewable here

James May's review of the Honda FCX Clarity (at the end of said episode) makes out that the very limited production (essentially concept) hydrogen fuel cell car is near perfect, ready to save us from the outdated uselessness of battery power cars. To really bang this home Clarkson has already demolished 2 Tesla Roadsters on the track earlier on.

What was plain ignored:

 - The hydrogen tank has the most flammable gas known to man stored at 340 times atmospheric pressure! I'm not scaremongering, this is still a huge issue holding back hydrogen cars; the gas is only a liquid at -250 degrees C (at standard pressure). Billions are being spent on developing storage substances that can hold and release the gas safely. So far they have efficiencies of about 0.1% hydrogen to substrate, by weight.

Above: 5000psi hydrogen storage tank being fitted to a Honda FCX Clarity.
 - Hydrogen gas has to be liberated from petrochemicals (oil) or electrolyzed from water using electrical energy. This process has much greater inefficiencies than with electrical battery storage.

Clarkson, and the "Top Plug" team, while continually pouncing on battery cars for refilling from power station electricity, appear to have swallowed the "hydrogen is the most abundant element in the universe" line and presume it's just lying about ready to fling in your car.

 - There is *no* hydrogen distribution system in place and is not going to be one anytime soon because it is so difficult and expensive.

 - There is (and has to be) a sizable lithium battery in the Honda Clarity for energy regeneration under breaking and buffering the power from the fuel cell (because it is too slow on it's own).

In fact, this car uses identical technology to the Tesla, except that a hydrogen cell recharges the drive battery, instead of having a bigger battery or a high efficiency petrol generator topping it up (like the PML flightlink QED Mini).

What I can't wait to see is the all British Lightning GT driving around the Top Gear track after their first cars are produced in 2009. They use PMLs 'Hi-Pa drive' system of 4 in-wheel motors, which give the Lightning the same 0-60 time as the Tesla, but a slightly higher top speed, no overheating problems and 4 wheel independent drive for perfect handling.

 Above: Lightning GT
This technology has also been taken fully on-board by Volvo who have a serious plug-in hybrid scheduled for full roll out in under 4 years, and there is the Ford F150 pickup truck concept demonstrating that big vehicles can be made green just as easily.

[UPDATED 2014-03-26 - Refurbished with new pictures.]

The Lightning GT seem to have dropped hub motors some time ago, and this link (previously included) is officially dead -

But more recently, engineering CEO superstar, Elon Musk, called out fuel cell bullshit too.

1 comment :

  1. It turns out the Tesla didn't run out of power or fail on track, the car pushing footage was faked:

    Clarkson also failed to mention that charge time would be reduced to 3.5 hours when using a high power domelstic line (such as power ovens/electric showers), something anyone who spends £100k on a car would install.