|
How much energy does the bicycle consume compared to the car? A road bicycle, on a flat and asphalted track, needs a power of about 60 Watt to move at 15 km / hour and 220 Watt to move at 30 Km / hour. The increase in power is not linear due to the friction of the air that increases with exponential law.The energy needed by the bike to travel 10 Km is therefore 60 * 2/3 = 40 Wh (Watt Hour) for the speed of 15 Km / h and 220/3 = 70 Wh for the speed of 30 Km / h. A medium-sized car at a speed of 50 km / h needs approximately 0, 105 gallon to travel 10 km, which corresponds to an energy consumption of 3840 Wh. The performance of the bike that goes at 15 km / h compared to the car is therefore 3840/40 = 96 times higher. The performance of the bike that goes at 30 km / h compared to the car is therefore 3840/70 = 53 times higher. If the car has the air conditioner running, the aforementioned ratios increase by at least 10%. What if the car was electric? The electric car is much more efficient than the combustion car but the bike wins hands down with it too. A medium-sized electric car to travel 10 km consumes 1.3 Kwh = 1300 Wh The efficiency of the bike that goes at 15 km / h compared to the car is electric is therefore 1300/40 = 32 times higher. The performance of the bike that goes at 30 km / h compared to the car is therefore 1300/70 = 18 times higher. In urban areas, cars move at the same speed as the bike due to traffic but, while the energy consumption of the bike does not change, that of combustion cars increases compared to the theoretical values ​​mentioned above for continuous braking, accelerating, waiting at traffic lights and queues while the energy consumption of electric cars does not change because consumption is zero when the vehicle is stationary. No means of transport can compete with the bike in terms of efficiency, not even those who walk can compete with the bike because with the same distance covered on foot and by bike, half the energy is consumed with the bike compared to walking. The astonishing efficiency of the bike has its roots in its weight much lower than the person carrying it, in the reduced friction of the tire compared to that of the car and in the lower friction of the air because the front surface of the bike + cyclist is at least 10 times lower. to that of a car. The car, on the other hand, uses 95% of the energy consumed to transport itself, since it weighs much more than the person who is in the vehicle and only the remaining 5% is consumed to transport the person. In practice, to travel comfortably and not struggle, the civilization of the car devours a frightening amount of energy that could be reduced if at least, in cities and in short trips, healthy people moved by bicycle. Riferimenti: http://www.onlineconversion.com/energy.htmhttp://bolt.mph.ufl.edu/6050-6052/unit-1/case-q-q/scatterplots/https://en.wikipedia.org/wiki/Fuel_efficiencyArticolo 4787 verificato al 2022-05-19 categoria: La Bicicletta |