All is not lost.
The overall thermodynamic efficiency of a state-of-the-art electric car is about 70-80% - battery discharge losses plus electric motor losses. The thermodynamic efficiency of an internal combustion engine is 20-25% at best.
div>
So in an electric car, you only need to store about 1/3 of the energy to drive the same distance.
Electric cars with in-wheel motors are considerably lighter than internal combustion engine cars before adding the battery. Electric motors have a higher power density then internal combustion engines so they are lighter. Furthermore, an electric car can do away with the entire drivetrain, since the electric motors are inside the wheels, the transmission, the exhaust system and the cooling system, saving even more weight. All this freed up weight and space can be taken up by batteries.
Electric cars have regenerative braking and don't suffer from idling losses in city traffic, making them more efficient still. Modern electric motors also operate close to maximum efficiency at all speeds, while internal combustion engine cars don't.
The overall result is that it is now possible to build electric cars with a range of 500 km, which comes close to internal combustion engine cars, even if the energy density of batteries, on a energy/weight basis, is so much lower than petrol.
Range is not what's holding back battery-electric cars anymore. What's holding them back now is the current cost and limited lifetime of Li-ion batteries. Mass production will brings costs down. But that is changing quickly.
Toshiba have introduced a battery that can be 80% charged in a few minutes. So re-charging at a charging station will take no longer than filling a tank.
Even if the electricity used to charge a battery car were 100% derived from oil power plants, it would still use less oil per km than an equivalent internal combustion engine car. Modern combined-cycle thermal power plants are 60% efficient. Electricity transmission is 95% efficient. Charging/discharging about 80% and the electric motor about 95%. And don't forget that refining crude oil into petrol and its transport distribution takes a lot of energy too.
And no emissions from these cars, silent and a super smooth ride. What you will be driving in 5 to 10 years time. Mitsubishi are introducing a 100% electric car in a year or two. I can't wait.
Bookmarks