Tag Archives: Consumption

The commuter’s consumption..

As with most people who drive to and from work on a daily basis my commute is pretty routine. At this point I can almost tell the outside temperature by the amount of electricity used (Oh no, not another weather post!–well not really bear with me). I’ve also noticed a disparity between the power consumption on my two daily trips: The ride in to work typically uses between 10 and 20 wH/mile more than the trip home.

I’ve always thought this disparity was due to the elevation difference between home (675 ft) and work (900 ft). Climbing 225 ft or descending 225 ft over 15 miles would explain the power consumption difference but I wonder if there is something else that is contributing?

My day starts pretty early when there are few cars on the road in the morning and at the end of the day there is significantly more traffic. This difference may be a factor: In the morning with little traffic I find myself doing the speed limit if not a little bit over–usually I can even get the lights timed perfectly and make most of then. In the evening, on the other hand, there is so much traffic that I’d be lucky if I could maintain a constant 10 mph under the speed limit. This speed difference is significant–you can see the wH/mile change quite a bit for a 10 mph increase in speed (we’re talking from 35 mph to 45 mph here). This would also explain the inconsistency in the values I’ve been seeing: Some days in the afternoon there is less traffic and some days there is more traffic.

Food for thought…