October marks our seventh month with our Nissan LEAF, as well as its first "maintenance" and the first recent monthly bill on our electric utility's winter rates.
Our LEAF continues to be trouble-free and very enjoyable and interesting to drive and to own. The car continues to be our family's first choice for any trips within its driving range, which includes the great majority of our driving.
Range Limitations Haven't Troubled Us
As in the previous months, we haven't had any problems running out of charge unexpectedly, and we've never been seriously concerned about that problem. The LEAF's electronics package includes several instruments that help us to plan trips, to estimate our remaining miles of charge, and to locate charging stations. The car has audible and visible warnings that appear when the remaining range is getting low, and a message appears that offers to guide the driver to the closest charging station, the locations of which are stored in the car's navigation system.
And if all of that isn't enough, some of the LEAF's early adopter fans have built add-on displays that show the remaining state of charge, and a very accurate paper chart that shows how many miles you can drive based on your average speed. The chart shows, for instance, that if you drive at an average speed of 60 mph, you'll use an average of 3.9 miles/kWh of battery power as shown on the dash and you can expect to drive 82 miles before running out of charge. The few LEAF drivers whom I've heard of running out of charge have been those who are deliberately trying to push the car's limits to find out how far they can actually go before the car stops. Nissan has even allowed for that eventuality by providing free roadside assistance and towing service for the first three years of ownership. In addition, AAA has set up a mobile EV rescue service in West Los Angeles with quick chargers mounted on trucks to help drivers with depleted batteries to get to the closest charging station.
A DC Quick Charger with Diesel Generator Mounted on a Trailer (NOT AAA's version)
A First Maintenance Visit
There is no required maintenance for the LEAF until a year of driving or 15,000 miles, whichever comes first. But a trip to the dealer for a tire rotation and a few visual checks is recommended at six months or 7,500 miles. As one of the earliest US owners of the LEAF, I want to be sure to stick to Nissan's recommended maintenance schedule and I want to help add to Nissan's database about the LEAF, so I scheduled a trip to Connell Nissan, my dealer in Costa Mesa, Ca. I also had noticed some edge wear on the front tires, and to maximize the life of the tires, I wanted to get that tire rotation done. Connell Nissan's General Manager was happy to offer this first service at no charge, and he'll even offer the same deal to any new LEAF owner regardless of whether they bought their car at Connell. No charge is a cost that I can live with, as I'm sure most would agree.
But with so few mechanical systems as compared with a gasoline car or a hybrid, maintenance for the LEAF will continue to be simpler and less expensive throughout its normal life. Brakes will wear more slowly since the car uses regeneration for much of its braking. There is no exhaust system, no ignition, no transmission in the usual sense of the word, and no fuel system. The cooling system is only used during charging, for cooling the charger and inverter, The gorilla in the room, of course, is the main (or "traction") battery. To completely replace the main battery will likely cost somewhere around $10,000 at current prices. But the battery is warrantied for eight years or 100,000 miles, and individual modules can be replaced if they fail, without replacing the entire battery.
First Recent "Winter" Electric Bill
I've been curious to see our electric bill for October because the beneficial high (55 cents per kWh) credit that we've been getting during the summer months for Tier 2 solar power generation drops to 28 cents in the winter. Days are shorter and heating our home uses significant power for the forced air blower. With additional family members living with us for a few months and with charging the LEAF for 1200 miles, we certainly have used more power in October than our solar panels have generated. Despite the "magic" of Time Of Use rates that have helped us to build a credit balance of about $360 through the previous seven months of our net metering year, October would clearly begin the months when our bills would no longer be negative (meaning credit balance bills).
True to my expectations, our bill for October was about $52. But subtracting this bill from our previous credit balance, we still have a balance of -$316 through the eighth month of our net metering year. For the remaining four months through next February, we can average bills of $79 per month and still end the year with a balance due of zero for running our entire household and charging the LEAF for close to 11,000 miles in the year. I'm estimating that we have a great chance to do exactly that.
But I get it that readers may be saying "Great for you, you have enough solar power that you can leverage Time of Use electric rates to your benefit, but what about the average family? What would we pay to charge a LEAF?" And that is a very valid point. The answer is that you can still get Time of Use EV charging rates, and the Super Off Peak rates are the same as they are on my rate schedule, 10 cents on Tier 1 and 16 cents on Tier 2. So at an average of 13 cents per kWh and 3.1 miles per kWh, your electric cost would be 4.2 cents per mile. If you drove 1,000 miles per month, your electric bill would go up by $42 a month. How much are you paying per month to gas up your current car?
How does this compare with your gasoline car or a Prius? The average gasoline car gets about 20 mpg and let's say a Prius gets 50 mpg, and a fuel efficient small car might get 35 mpg. At $4 per gallon of regular gas, the average car costs 20 cents per mile, the Prius costs 8 cents per mile and the fuel efficient small car costs 11.4 cents per mile. If you drive 12,000 miles per year, by driving a LEAF at electric rates like mine, you would save $1,896 per year compared with an average 20 mpg car, $456 per year compared with a Prius, and $864 compared with a fuel efficient small car. As gas prices rise, these savings will grow, and of course, if you have different electric rates in your area, that will affect your calculations. Many areas, such as the Pacific Northwest, have abundant and cheap hydro power, so it is cheaper and greener to drive electric there. In other areas, like in the East, a larger proportion of the power may come from dirtier coal and the electric prices may be higher.
The Numbers:
Month: October 2011
Total Miles at Month End: 6,396 miles
Miles Driven in Month: 1,203 miles
Electric Power Used for Charging in Month: 368.2 kWh (measured at wall power source, includes public charging)
Public Charging in Month: 38.54 kWh (Includes 15.6 kWh charging at a friend's garage)
Home Charging in Month: 329.66 kWh
Energy Efficiency, Month of October: 3.27 miles/kWh (wall to wheels)
Total Charging Energy Used, Lifetime: 2,017.1 kWh (Includes public charging)
Energy Efficiency, Lifetime: 3.17 miles/kWh (wall to wheels)Most Electric Energy Used for Charging in a Day in October: 28.8 kWh (7.8 charging hours, done in two charging sessions, including one session at a friend's garage)
Most Electric Energy Used for Charging at Home in a Day in October: 19.1 kWh (5.16 charging hours)
Least Electric Energy Used for Charging in a Charging Day: 5.3 kWh (1.4 charging hours)
Average Electric Energy Used for Charging in a Charging Day: 15.3 kWh (4.15 charging hours)
Household Power Used for Month: 785.35 kWh (without car charging)
Total Power Used for Month: 1,115 kWh (includes car charging)
Solar PV Power Generated for Month: 665 kWh
Net Power Used or Sent to Grid for Month: 450 kWh net used
Electric Bill, So Cal Edison, Schedule TOU-D-TEV: $52.17 (A charge in this amount will be added to our net metering total charge for the year.)
Solar Net Metering Year Total kWh Used at Month #8: 669 kWh (Total of 669 kWh net used for the year)
Solar Net Metering Year Total Cost at Month #8: -$316.42 (Total cost is a credit for the net metering year to date due to TOU rates)
Cost for Charging Car in October: $0.00
Cost per Mile: $0.00
Cost for Charging Car, Lifetime: $0.00
Cost per Mile, Lifetime: $0.00
(If We Didn't Have Solar Power, Est Cost for Charging Car in October: $42.86)
(If We Didn't Have Solar Power, Est Cost per Mile in October: $0.036)
Average (Mean) Miles per Driving Day in October: 38.8miles
Average (Median) Miles per Driving Day in October: 37 miles
Longest Day's Driving in October: 104 miles (twice, both trips included charging mid-trip)
Shortest Day's Driving in October: 1.1 miles
Number of Times we Took the Prius Instead of the LEAF Due to Low Charge: Never
Unexpected Low Charge and Unable to Reach Destination: Never