On Sat, 09 Mar 2019 10:23:31 +0000, dennis@home wrote:

====snip====


25kW for motor running a car at about 35-40mph.

More like 2 to 5 KW at a steady 35 to 40mph on the level...

So five miles will use about 8 minutes at 25kW.
That is about 3.4 kWHr.

Assume 5KW consumption and 35mph. That's 8.57 minutes which works out to
some 0.7KWH's worth of energy from the battery.


If you run at motorway speeds that will easily be twice that.

Only if you were referring to the energy consumed per unit distance. If
you assume a steady 70mph versus the 35mph, you will need at least four
times the power (double the rpm with at least double the torque to
overcome the doubled up aerodynamic drag forces). Four times the power in
half the time represents twice as much energy (KWHs) per unit distance.

I've assumed low Reynolds numbers here (35 to 70 mph speed range). At
high Reynolds numbers (150mph and faster?), the power required to
overcome aerodynamic drag eventually transitions to the cube of the speed.


There is no recovery from braking unless you are stuck in a queue.

That makes no sense.


If you commute is less than five miles you may as well use a bike.

That rather depends on the nature of the journey and the fitness of the
commuter. For someone in good health with no need to carry excess
baggage, that can be a very cost effective way to justify the consumption
of an extra Mars Bar or two without the risk of joining the ranks of the
morbidly obese.

However of course, this mode of travel has a higher micromort rating
than that of travelling by private car, you just might end up a skinny
dead person with more willing coffin bearers at your funeral. :-(


--
Johnny B Good