Carbon Footprint Reduction: Stumping Trump with an Electric Car
Now that the ole Trumpet has made it official, it’s an even better time to start doing something about reducing your own personal carbon footprint. Led by former New York mayor Michael Bloomberg, environmentally minded cities and states (including I am proud to say the state of California) are going to try to attain the US carbon targets in the 2015 Paris Agreement without any federal participation, and thereby give the middle finger to the Trumpet, the Koch Brothers, Mitch McConnell, Steve Bannon, Paul Ryan, and the Republican Party in general. You can help too, and one really straightforward way is to get an electric car or plug-in hybrid or even a simple hybrid if you don’t have anywhere to plug in a car where you park at home. Carbon emissions from transportation, and especially from personal vehicles, are around 27% of the total carbon emissions because today 90% of the transportation fuels are petroleum based.
I purchased my first alternative fuel vehicle in 2002, a 2002 Model I Prius. The Model I has a hybrid gas-electric power train, and gets around 40 mpg, which, at the time, was about 30% greater than the next best car on the market, the Toyota Corolla. The local Toyota dealership had received one as a gift from the home office in Japan for having sold the most cars of any dealership in the US. But the driving experience was less than stellar. Though I never measured it, the 0–60 acceleration time felt like 20 seconds. It complained when climbing hills, though it managed the hills fine without slowing down, and the suspension was so squishy that driving it was kind of like driving your living room sofa. In other words, the experience was kind of like using an Apple II or IBM PC in 1987.
In 2006, I started looking into electric cars and plug-in hybrids. The only commercially available electric vehicles at the time were so-called Neighborhood Electric Vehicles (NEVs). These were nominally street legal cars that have a maximum speed of 30 mph and generally used lead-acid batteries for propulsion, actually little more than enclosed golf carts. They could not be driven on a freeway, and the attention to quality in their design and construction left much to be desired. Cal-Cars, an organization of engineers and others interested in decarbonizing transportation, had formed in Palo Alto, and was promoting conversion of the Model II Prius into a plug-in hybrid. In typical Silicon Valley fashion, they built a couple prototypes and began showing them around.
In late 2007, A123, a now bankrupt battery startup, began selling a conversion kit for turning the 2008 Model II Prius into a plug-in hybrid. The conversion kit consisted of a 5 kwh lithium iron phosphate (LIPo) battery pack, together with an on-board AC-DC converter and hardware so that the car could be plugged into a standard 110v, 15 amp US domestic electric socket, charge time about 6 hours. The battery installed into the spare tire well in the back of the car, meaning that you needed to give up your spare tire, see the photo above, and a small switch and indicator lamp was installed on the dashboard to turn the system on or off. As part of the conversion, the car was fitted with stiffer shocks to take the extra weight, around 200 lb over the stock Model II. I bought a 2008 Model II Prius in spring 2009, and had it converted by Green Gears, run out of Pat’s Garage in San Francisco, in fall of 2009. In addition, I had the iridium spark plugs that came with the car removed and had Pulstar plasma plugs installed. Pulstar plugs have a built in capacitor and deliver a stronger charge, so that more gasoline is burned, theoretically improving gas mileage and reducing pollution from unburned hydrocarbons.
The LIPo chemistry is exceptionally stable unlike the more popular chemistries used by most electric and plug-in cars today, but for that it is not as energy dense. A123 promised 30 miles of electric range, but I never saw more than maximum 20 miles. With the Pulstar plugs, I frequently saw over 100 mpg (the Prius mpg indicator didn’t show more than 99 so I can’t tell for sure) when we were using the car around town. The system worked by charging the main hybrid battery, but the extra battery did not participate in regenerative braking (charging from recovered braking energy), so once it was depleted, it was 200 lb of extra weight dragging on your gas mileage until you recharged it.
At around 30,000 miles, the Pulstar plugs gave out and the car started chugging. Fortunately, the engine was undamaged, though I’ve read reports from people who had the opposite experience. I had my mechanic reinstall the iridium plugs and the car was once again good to go. In 2011, we bought one of the first Nissan Leafs, and began using the plug-in Prius mostly for longer trips. The gas mileage plummeted to around 55 mpg, slightly above what today the new Prius Prime achieves. The plug-in hybrid system suffered an ignominious end though. The battery balance board shorted out when my nephew, who we had loaned the car to, pulled out of the garage without unplugging the battery. Unlike the plug-in hybrids available from manufacturers today, the aftermarket plug-in hybrid system had no interlock with the ignition to prevent starting the engine if the car was still plugged in.
With the Nissan Leaf, we have completely decarbonized our local transportation when we charge it from our solar PV system. Sometimes in spring, I charge it at work instead, to help reduce solar curtailment (when the California independent system operator disconnects solar from the grid due to too much power generation). California has a problem with curtailment when solar electricity from the utility scale solar farms in the Mohave soars in spring before people in San Bernardino and the Central Valley begin turning on their air conditioners. The Leaf is a great drive, snappy acceleration, really great handling, everything you would want in a car.
Except…after only 30,000 miles and 6 years, the battery has begun to lose range. Now, it is down by more than 25%, which given that the original range was only 80 miles, makes it hard to drive for more than a couple days without recharging, and impossible to drive to the San Francisco airport and return without recharging. Nissan guaranteed the battery capacity for up to 5 years if you lose more than 25%, but I started losing capacity at 4 years and didn’t fully lose 25% until this year. The basic problem is that the Leaf battery system is air cooled, unlike most other electric cars today which use liquid cooling, like the radiator on a gasoline powered car. So when the batteries are charging or if the weather gets hot, they can easily become damaged by heat. I saw one bar of capacity (around 8%) disappear after a hotter than normal day in early May this year.
While there are now some cars that have over 200 miles in range, the time for recharging is still long, even if you use a DC fast charger, so as a practical matter we also have a new, 2017 Prius Prime. You can get about 25 miles on the battery, which is enough for short trips around town, or sufficient to up the gas mileage on longer trips. The Prius Prime gasoline engine gets 54 mpg in standard hybrid mode, the same as I was getting with my clumsy aftermarket add-on, the best mileage of any plug-in hybrid except the Hyundai Ionq, which gets 55. But the best thing is, it drives like a sports car! No more of that squishy suspension, and hesitation when you stomp on the accelerator, as if it has to decide whether it wants to go fast or not. The braking is much better too, they’ve removed the hybrid braking lag which made accommodation to driving a hybrid difficult. Plus it has loads of new safety features, like automatic braking if a pedestrian steps out in front of you. The only complaint I have is that they put the charge port in the back instead of the front like with the Leaf, so it is really hard to charge in my garage.
Bottom line though is what was the contribution of electrified personal transport toward reducing my carbon footprint? The 2002 Prius only made minimal impact, removing 1014 kg out of a total of 12,124 kg of 2002 emissions, or 8%. The 2008 plug-in Prius had somewhat more effect, 1014 kg out of 7154 total 2008 emissions, or 19%. The Nissan Leaf had an even greater effect, 2538 kg out of 5241 kg total, or 48% of the 2010 value, almost half. I don’t have any figures for the Prius Prime yet. All of this was without any major impact on my ability to get around, and while the initial experience of driving a hybrid was pretty lame, today an electric or plug-in hybrid is a joy to drive.
The technology for electric or partial (plug-in hybrid) electric vehicles has come a long way since I bought my first hybrid in 2002. There are electric or plug-in vehicles in practically every class, with the exception of large SUVs and pickups. Because electric cars are so simple mechanically, you rarely have to take them to the garage for service. My Leaf has only been to the garage once, for a software upgrade. There is even now an affordable all-electric that has over 200 miles of range, the Chevrolet Bolt. Plus, if you don’t want to buy a new car, there are used plug-in hybrids and electrics available. Used Leafs are an especially good deal, you can get one for less than $8000 with a few bars missing, great for around town driving. So if you want to get serious about taking a step towards reducing your carbon footprint, there is no easier way than getting a plug-in hybrid or electric car.
