Monitoring The Car
We've added power-usage monitoring to the EV. Tom hooked up a watt-hour meter (the type the power utility uses to measure your electricity usage) to the EV's dedicated power line. By using this meter, it will be possible to tell just how much we're spending to "fuel" the EV. We're going to put the figures up here for you to see.
|Miles Per kWh
|Cost Per Mile
|Miles Per kWh
|Cost Per Mile
Note: Cost Per Mile based on $.07 per kWh
Update 4/1/01 -- Starting this month, the car will be garaged for its conversion to NiCD batteries. See our report on the conversion process for more details.
Update 6/1/00 -- OOPS! This month, we don't have useful energy usage information due to the fact that we have been charging the new electric pickup (see our E-10 Restoration page) using the Force's outlet! This is now corrected, as the E-10 now has its own outlet, on a separate meter. Next month we'll have a return to meaningful numbers, since we can't guess how much the truck actually put on the meter.
Update 1/1/00 -- A high energy-usage month! Our mileage was down quite a bit because we have been using the electric heat extensively. Another factor in this month's usage is the fact that we parked the car outside for over a week in very cold temperatures (around 0 degrees F) while I used the garage to do a large woodworking project. This caused the car to use its thermal management system to warm the batteries, which uses a bit more electricity.
Update 12/22/99 -- As of today, we have owned our Force for two years. It has become our primary transportation, and has proven itself to be a very reliable vehicle, with only two days of down-time due to a charger failure in late 1998 (and it was only down those two days because it was a weekend and the replacement charger, shipped by Federal Express on a Friday, arrived on Monday).
Update 7/1/99 -- With this month's trip to Amherst, Wisconsin (303 miles round trip), we have the highest number of miles we've ever travelled in a month (731), and just coincidentally, our highest efficiency ever, at just over 5 miles per kWh! See our Trip to Amherst page for details on the trip.
Update 6/1/99 -- Lots of news on this report. First, this reading gets a full year of regular energy usage under our belts and lets us see just how the car performs over an entire year. Based on this information, we can see that our photovoltaic system must generate approximately 1400kWh over a typical year (or 3.7kWh per day) to offset the car's usage. It should be able to do this. Also, note the drop in efficiency recorded on 5/1/99 (2.3 miles per kWh) -- This was an indicator that something was wrong -- The miles per kWh usually goes up as the weather warms up. It turns out that the car's tires were low on air pressure, causing it to work harder and use more energy to get where we were going. Moral: check your tire inflation regularly (even on internal combustion cars)! I fixed the inflation problem and you can see the jump in miles per kWh on this month's reading. As of this reading, the car is getting its energy from the sun, so the cost per mile figures from here on are strictly informational only.
What The Numbers Mean
Over the long-term, an EV winds up costing about the same amount to run as an internal-combusiton vehicle. The benefits are lower pollution (pollution occurs only at the power plant, where it is easily controlled) and the fact that the EV uses energy more efficiently than an internal-combustion engine (ICE):
1 kWh = 3409.5 BTU
1 Gallon Gasoline = 125,000 BTU
EV uses 3409.5 / 3.25 = 1049 BTUs Per Mile (using 3/3/98 Mile/kWh
ICE uses 125,000 / 35 = 3571 BTUs Per Mile, assuming 35 MPG
EV is 3.4 times as efficient
For our van, which gets 23 MPG, the calculation is:
125,000 / 23 = 5434.7 BTUs Per Mile
This makes the EV 5.18 times as efficient!
As time goes on and we gather more details on various aspects of our EV, we'll put more technical information here.
Back to main EV page
This page last edited May 27, 2001