Recently a totally new concept was launched in some countries, including the UK, based on the exciting digital or crypto currency innovations of recent years, that could actually empower individuals to convert their daily steps into digital money that they can spend, save or whatever, just like our existing currencies. ‘Bitwalking’, as it has been named, could effectively give everyone the freedom and opportunity simply to make money by walking!

All media are enthusiastic about the constant increase of car-pooling; in France, it grows by 100% per year, its champion being Blablacar with 2 million passengers per month.

But is car-pooling really good for the planet? Not so sure, in fact.

For sure, 2 million passengers per month represent something considerable, representing more than 2 000 double-size trains.

Studies show that mostly, car-pooling websites attract users who consider that train or plane are too expensive. For sure, for 2 persons or more, fares of train journey cannot compete with sharing cost of riding by car, and if you are alone, only low-fare train tickets can compete with car.

But what about CO2 emission?

The myTripSet too on website SNCFVoyages.com, which compares prices and CO2 emissions, gives some interesting information. Train is widely the least CO2 emitter. E.g. a journey Paris-Nantes in TGV emits only 4 kg of CO2. To be compared to 75 kg of a car * and 90 kg of plane. SNCF estimates that average CO2 emission level of train is 13 g per person and per km.

OK, then car-pooling is not environment friendly if we look at gross figures.

Anther argument, does car-pooling lower the number of cars on roads?

It would be great, but truth leads us to answer no in fact: even if they don't have paying passengers, most drivers would not cancel their journey and, mostly, they would not travel by train either.

On the other side, most passengers do not own a car: if not travelling by car-pooling, most passengers would have cancelled or postponed their journey, instead of travelling by train which they often cannot afford. Then, contrarily to a common idea, long-distance car-pooling websites (like Blablacar) ease and increase the number of travels by car, and they take some customers to train, which is more ecological.

This is also valid for home-to-work daily rides: car-pooling permits to share parking places but its use is an incentive to come to work by car instead of using bus or train. Once again, not very ecological.

As a conclusion, car-pooling is not very environment-friendly. However, the other arguments are still valid, like not travelling alone on a long journey, sharing cost or increasing your security (spontaneous and local car-pooling like www.zenoncar.com permits to find a driver to return home if you are unable to drive your own car, e.g. drunk or injured).

Mid-March 2016, Honda announced they will launch a fuel-cell car (powered by hydrogen) by the end of 2016. Despite the price (over 57 600 EUR TTC in Japan, probably even more expensive in Europe), this car represents a hope for green cars.

At the same time, Tesla announced they will open a new show-room in Luxembourg city for their premium electric cars, around end of second semester 2016. From this date, Tesla cars will be available in Luxembourg, while until now they are distributed by the Belgian importer.

Those two good news bring to us a question: which is the most environment-friendly one? Which one should you choose, assuming that you can afford a Tesla (starting at 69 100 EUR TTC)?

First criterion to look at is autonomy: considering the 550 km of autonomy claimed by Tesla (closer to 500 km in reality), the 750 km of autonomy claimed by Honda seem to be a huge advantage. That could be true if we had already a network for hydrogen distribution, which is not the case or the moment. In fact, in France, only 9 hydrogen stations have been already built, forgetting at least 80% of territory. Do not even think of Luxembourg: you have more chances to find palm trees in Norway than being able to refill you car with hydrogen.

On the contrary, Tesla has built all over Europe a network of "superchargers", which can recharge more than 80% of your car in 20 minutes, and fully charge in 30 minutes. Barely time for a coffee or a lunch. Moreover, the use of these superchargers is totally free, the user even doesn't pay for the power!

Second criterion is the environment. How is produced the hydrogen that will power the Honda fuel-cell car?

Hydrogen can be produced mainly by two processes: electrolysis or from hydrocarbons. Electrolysis uses electricity with an efficiency rate of 7 to 10%, which obviously induces a low power rentability compared to the Tesla, which draws its power directly from electricity with an efficiency rate superior to 90%. The use of green power (wind, hydroelectricity, sun, etc.) allows to reduce the impact on environnment but will not increase the overall efficiency rate. Whichever is theprocess of producing electricity, the most efficient is obviously the best.

The second solution to produce hydrogen is from hydrocarbons, which gets a double drawback: not only its efficiency (80%) is still lower than Tesla, but also the pollution (refusal) generated by this form of production. On top of that, using fossil energy is not sustainable on a long-term basis.

As a conclusion, for the moment the electric car wins the fight. At least until hydrogen improves its distribution and the efficiency of its production.

Nevertheless, actually driving green is quite a luxury: 57 600 EUR for Honda + hydrogen loads, 69 100 EUR for Tesla (but free power from superchargers), keep these cars reserved for wealthy people. A first step on the way.