Thursday, December 25, 2014
Based on a price of about $4.00 per gallon of gasoline, I ran some calculations to compare the cost-per-mile of driving an electric car versus the cost of a gasoline powered car. The result was that it costs roughly 3.6 cents-per-mail to drive my electric car and about 19 cents to drive the same mile in a gasoline powered car. That made my savings after driving 10,000 miles about $1,540. This assumes an average price for fuel of about $4.00 per year. In California, the last few years have seen prices fluctuate between $3.40 in the winter and $4.60 in the summer, so the $4.00 makes a reasonable (and convenient) average.
What happens when the price of fuel drops substantially lower in the winter months? Some recent oil-market manipulations have dropped the price of gasoline to about $2.55 per gallon. Assuming that the summer price swings by a similar amount to $3.75 per gallon, the average price over the year might be $3.15. How does this substantially lower price affect the per-mile cost of gasoline-powered travel? Using the assumptions that I listed in my earlier post titled “Only 3 cents a mile”, the new cost-per-mile is 15.5 cents, or about 3.5 cents less per mile. So, the money I would have saved during this abnormal year of relatively low fuel prices will drop by about $350. Does this mean I lost this money? No … my own costs are determined by the cost of my electricity (which was $0 last year, thanks to the sun). It means that had I not bought my electric car, I would have been paying less per mile this year to drive a gasoline powered car (which lowers my hypothetical “savings”).
My biggest concern here is that the lower price of gasoline will motivate more people to purchase bigger, heavier, gasoline-powered cars, trucks, and SUV’s. These larger vehicles require more power to move them, which demands a larger engine. And, to compete in the race for ever more horsepower and faster acceleration, these bigger vehicles need even larger engines to be able to keep up. All of this generally means that more people driving these vehicles will burn more gasoline needlessly, without much concern for how the emissions from these larger engines impact our planet. High gasoline prices were actually helping to slow the rise in emissions by motivating people to favor better fuel economy when it came time to buy a car.
Tuesday, December 16, 2014
What a shock! (pun) I plugged my car in, activated the charger, and then went to bed. In the morning I needed to take a short trip and was surprised to see that the car had not charged at all. I was running short on time and had to drive on the remaining charge in the battery. When I returned home, I again connected the level-2 charger and activated it. It came on for about three seconds, then shut off. This repeated about five times until I abandoned my attempts. I decided to drive to a nearby public charging station to determine whether my car was at fault. I connected and the car began charging without any problem. So, now I am faced with two problems:
First, I have to charge using my level-1 (110-volt) charger until I am able to install a replacement charger. This means that I must plug in the car the moment I return home from work in order for it to charge fully before I need to leave in the morning. It should take about 13 to 14 hours to fully recharge after my drive, and plugging in at 8:00pm gives me just enough time to accomplish this. By working from home on Tuesdays and Thursdays, I can plug in even later and expect a full charge before noon. So, the level-1 charger is working for me, although just barely. I really do need to replace the level-2 charger.
Second, I have to find a level-2 charger that meets my needs. My charger is installed outdoors, so this means I need a weather-proof enclosure for the charger. I also have a 220-volt outdoor outlet with a weather case installed, which means I cannot easily adapt to a hard-wired charger. These two requirements eliminate most chargers from consideration. And those that do remain have only a 12-inch receptacle cord, which is not very compatible with an outdoor installation. My old charger has a 3-foot cord to plug into the wall and I was able to mount the opening to the weather-protecting box on the bottom side. To accommodate these new chargers, I will need to remount the box (and outlet inside) so that the hole is on the upward side. I’ll also need to add an O-ring to the cable to further block any moisture. (It seems that new national electrical standards require that the wall cord be 12-inches long.)
|My original level-2 charger by EV-Charge America|
I did try to have the two-year old charger repaired, but apparently I was one of the luckier customers of this charger. Many customers never received a charger (or a refund), and others received defective units that never worked (and were leaking a black ooze). My charger worked flawlessly for 31 months before giving up the ghost, so I guess I should count my blessings. While researching repair information, I found a few articles mentioning law-suits against the manufacturer and a jail sentence for the company's owner. The irony is that I felt that this product (when working) was superior in many ways to the competition. It is just too bad that EV-Charge America could not have found a way to bring this product to market successfully.
I’ll let you know what I buy as a replacement.
Tuesday, December 9, 2014
After driving the i-MiEV for several months, I wanted to test its capability and range under more unusual driving conditions. I knew that the car used more electricity driving uphill than on a level surface, and it had been a while since my last visit to the mountaintop winery near me, so I decided to head up the mountain. The first thing I checked was the distance to the winery from my home. The routing suggested by Google Maps was the obvious and most direct route. This route starts off with 11.2 miles of freeway (each way) which would draw down the battery by about 7kwh round-trip, or a little less than half the charge. That left more than half the charge to get up the mountain and back down. It was another 3.5 miles to the start of the mountain climb, and 4.3 miles up the mountain (about 1,500 feet of elevation change). I figured that if I could make it up the mountain on 6kwh, I would get home safely. (That amounts to 0.72 miles per kwh, which is terrible.) So I decided to go forward with the trip.
|Google Maps' proposed route up to Ridge's Monte Bello tasting room|
As I started driving, I created turn-back thresholds for the battery consumption in my mind, beyond which I would have to turn the car around and head home before reaching my destination. This is the sad impact that range anxiety has on us poor fools who overthink or over-worry about their electric cars. Of course, it’s better to be prepared for failure than to deal with the consequences of going too far up a mountain road. As I reached the base of the road up the mountain, the charge meter showed that I had used four ticks (which amounts to 4kwh), as expected. So, I continued up the hill. You can imagine my shock after driving the first mile and watching another tick (1kwh) disappear from the gauge. Still, at this rate, I would make it to the winery with energy to spare, so I trudged on. The second and third ticks disappeared with less of a shock as I noticed the rate continued at about 1kwh per mile. Finally I arrived at the winery with about a half a charge remaining. The drive home would use less energy, so I knew I would make it home safely.
After enjoying a modest wine tasting and giving my body a little time to process the tasty stuff, I left the winery for my drive home. Much of the drive down the mountain required very little energy, and often times I was regenerating while the road sloped downward. Nearly as shocking as watching the first tick disappear while driving up was watching the first tick reappear on the way back down. This time, the shock put a smile on my face. By the time I had reached the bottom of the hill, I had regenerated about one and a half ticks (1.5kwh). Now I was faced with driving the remaining 12 miles on the highway with the 9kwh charge remaining in the battery (about 30 miles of range), which I could do easily. So, in all my worry about getting up the mountain, I forgot to factor in the regenerative effect of driving back down the mountain, which changes the amount of charge needed to complete the trip.
So, here is the mind game about driving an electric car with regenerative braking up and down a mountain. I used about 3kwh of electricity to drive about 9 miles up and back down the mountain. This rate of energy consumption is a little worse than it is when driving on the freeway. But, the trick is that without at least 4kwh of charge in the battery, I never would have made it to the top of the mountain. I needed more than I used on the whole trip just to get half-way. It is conundrums like this that have me thinking I’ll stick to being a flat-lander.