Did you know that traveling by car at 105 km / h instead of 120 km / h allows you to save about 15% of fuel? And what to keep inflated tires and aligned (what is called convergence) increases the number of kilometers that can be traveled with a liter by about 3.3%? Taken together these two things don't make a good one savings? Remember this especially now that we are talking about travel and holidays, for those who can afford them: give them displacements by car, but not only by car, quite a lot is possible energy saving, with benefits for our pockets and for the environment.
Let's go back to the car. Air conditioners are useful but also expensive because when they are running they can also consume 10% more fuel, which is no small feat. However in the displacements at speeds above 80 km / h it is preferable to turn on the air conditioner than to open the window because the aerodynamic resistance would consume even more power.
If when we get into the car the passenger compartment temperature is higher than the outside temperature, it is a good idea to travel for a few minutes with the windows down before turning on the air conditioning: cooling a few degrees thanks to the outside air will prevent the fans from doing the heaviest work and will allow quite a lot energy saving. It goes without saying that the air conditioning system should be turned on only when necessary, and in the mid-seasons (which are still there) it can be done without.
The ways to save energy give it displacements by car there are many: for example consider the possibility of switching to a hybrid car (petrol + electric or diesel + electric) or high biodiesel energy efficiency. Those who live in the city and mainly make short trips could also consider a electric vehicle, which today have a respectable autonomy and do not have the problem of limited traffic areas or walking Sundays (which cost us a lot with the overtime of the police).
Obviously, there is not only the car. For the displacements short the energy saving is to walk or in bicycle. Of bike there are the traditional ones, which in 2012 in Italy surpassed cars for number of pieces sold, and there are those a assisted pedaling: real gems of technique, some even vintage like the Velorapida, which allow you to move effortlessly at 20 km / h with about fifty km of autonomy thanks to small electric batteries that recharge quickly at home.
Of pedal assisted electric bikes there are also some equipped with photovoltaic panels which help (if not complete) the recharging of the battery when cycling in the sun. Who wants to go even further in the energy saving and in reducing pollution, it can focus on the real thing pedal assisted solar electric bike, which works without batteries with the sole contribution ofpower produced by photovoltaic panel on board: here, however, we are still at the prototype level and a vehicle like the Sunbike is not the most suitable for displacements in the city (for an original summer vacation, yes).
And public transport? Given that they too pollute (some too much) and that they should be built thinking about reducing emissions and savings of power, the displacements by train, tram and bus are certainly preferable to those by car because: they have a lower environmental impact, reduce traffic and are forms of shift more relaxing. Avoiding stress, after all, is also a form of savings of power.