Monday 7 September 2015

"How's the car?"

It's a question I'm getting used to. Folk ask it regularly and I guess it's to see how, on a simple curiosity level, I'm getting on with the car. It's perfectly possible they are hoping to discover that it has been a disastrous decision in the first place. But I know that some genuinely see me as a pioneer in a new motoring paradigm that has a way to go before becoming mainstream, and that they are keen to see how it is progressing before taking the plunge themselves.

Driving experience

A modern electric car like the Leaf is no slouch. When asked to shift, it does so with split-second reaction, cranking up to the desired speed with smooth, quiet, almost ruthless efficiency. Take-off torque is instant; an unfamiliar response for anyone used to a conventional engine trying to get up past its inefficient low revs. Moreover, that quick, slick acceleration comes from merely a dab on the right pedal. There's no messing about trying to "stir a bucket of nuts" (manual gearstick).

I expect that such performance is normally the province of drivers of BMW, Porsche or Mercedes automatics. But I predict that when such sporty capability spreads into the hands of the wider driving population, especially the more impatient among us, we'll start to see more instances of people darting into tiny gaps in the traffic to gain those few seconds lead on their fellow road user during the rush-hour race. Me? I just like to tootle along with gentle acceleration, only gunning the pedal when the conditions require it. Honest!

Having said that, the Leaf is changing my own driving habits. For years, I drove to minimise petrol consumption. It was a game aided by the consumption meters included in modern cars. I wanted that MPG number as high as I could get it without being dangerous or annoying to other drivers. When I bought the hybrid Yaris, its characteristics made me modify my techniques whereby I could force the car into EV mode and keep it running on its meagre battery for a bit when it suited me.

Suddenly, having gone to pure electric power, there seems much less need to strive for such efficiency. More and more, I drive as feels appropriate for the surrounding conditions without much thought as to how much electricity I'm using. Compared to petrol, my 'fuel' is very cheap and often free. I'm still a relatively slow driver and tend to keep to the speed limit far more than other drivers so I am used to the whoosh-whoosh of cars on the dual carriageways overtaking me.

For the first time in my life, I engaged cruise control. It's a bit scary at first and a heightened sense of awareness was needed to think how I would transition to normal driving should the need arise. It's so weird taking the foot off the pedal while the car is still motoring forward. I could get used to it, however. Yet, having an electric car with limited range, I'm not likely to be doing much long-distance motorway driving, when cruise control makes particular sense. It's inclusion in the Leaf feels like a manufacturer throwing in lots of bells and whistles to justify the car's high list price.

Where the Leaf is most comfortable is city driving; fast or slow. The set-up of the accelerator pedal allows deft control throughout the speed range and that includes slowing down. I always drive in 'B' mode, which is the same as 'D' (Drive) but with added regenerative braking when backing the foot off the pedal. The car is particularly relaxing to drive in traffic jams.

Ecology

My Yaris Hybrid had an 'Eco' button. When enabled, it limited the car's acceleration somewhat. I tried it for a while and then decided to forego it. I felt that as I tended to accelerate slowly anyway, it was only forcing me to do on all occasions what I did on most occasions anyway.

Today I pressed the 'Eco' button on the Leaf.

Wet blanket or what! The Leaf suddenly becomes a granny's car. All at once, this lively, keen and instant panther transforms itself into a sloth. Slow and lugubrious, it feels unwilling to go anywhere. Engaging 'Eco' did add a few miles to the range prediction so I guess it could be seen as a range extender if the occasion required it.

Long distance Voyager

Bathgate is a former mining town that sits nearer to Edinburgh than to Glasgow. It is home to a well-known heavy rock venue, the Dreadnought. As my son and brother-in-law were playing there with their band StillMarillion, I decided, at 33.5 miles distance, attending this concert would be a fun test of the car's range and what it was like to use most of its capability in a single journey.

It was a lovely evening, early September with the Sun out so we could get away without climate control. The battery was topped up to 100% and the range prediction said 95 miles. If it was accurate, I would be using 67 of those, leaving 28 in the battery. We set off on the M8 motorway and climbed to the its high section where the main Central Scotland transmitters are, altitude about 900 feet.

Throughout the climb, I watched with only the mildest concern as the battery percentage dropped and the predicted range dropped even faster. It was then with a little relief that we started down the other side of the country to Bathgate. As soon as we did, the range figure just stopped changing. By the time we parked, we had used 41% in order to go our 33.5 miles.

Since Bathgate is a couple of hundred feet higher than home, I figured my return would be more frugal. It wasn't. For a start, I had headlights on as it was dark. Additionally, part of the motorway had been closed, taking us off on a diversion. I also think the higher density of the colder air increases the drag on the vehicle, and I did use the heater for a short while. These influences more than cancelled out any gains that would have been made by going downhill. A mile or two from home, the battery hit 19% and the range prediction began to flash. The battery status display was then replaced by a warning notice telling me that its charge was low.

As we pulled into the driveway, the stated range was 16 miles, a good bit less than my original guess. Our diversion had added a mile or two and it's clear that in colder weather or with unexpected diversions, it would have been easy to find ourselves short. A good lesson on what expectations should be, especially as we go into winter.

Here comes the Sun

With the battery low, I elected to leave it on charge overnight and figured it would take about 18 units of electricity to top it off. Here's how I figure that. Although the battery has a capacity of 24kWh (24 units), I read somewhere that only about 21.5 of those are useful. If the battery was at 18%, then 21.5 x 0.18 = 3.9 units remaining. I'd have to buy 17.6 units at a cost of £2.10.

It turns out that had I decided to charge the car during the afternoon of the next day, I could have saved myself a bit of money. These past few days have been unusually sunny here in Scotland. Today I wanted to top the car off by putting 4.5 units in it. I started the charge once the Sun had come around to face our solar panels and I was getting over 2kW from them.

Normally what happens when there is lots of power from the panels is that the house takes what it needs and the rest of the power goes into the grid. Since the quiescent consumption of the house is about 500W, there is a substantial amount of power available at these times and my feed-in tariff from the energy company will pay me whether I use it or the grid does. By plugging in the car, all that spare power goes into its battery. By the time the charge was over, my retail meter (the one that tells me how many units I'm buying) had only clocked up a single unit, plus or minus a unit. (It doesn't have a decimal point so is inherently lacking precision.) In other words, most of the electricity that went into the car came from the Sun.

Of course, it will be different in winter when the low Sun and the Scottish clouds will cause my solar generation to head down to barely a unit a day. Still, the lesson is to charge when the afternoon Sun is shining.

I love spreadsheets

I have a mug sitting in front of me here that says "I [heart] spreadsheets". I get a real kick out of using spreadsheets to log data of interest to me and I use them to understand and analyse its trends. Among the list of parameters I track (a list too long and embarrassing to mention here) is the house's electricity purchase, measured in units called kilowatt-hours (kWh).

When the Leaf arrived, I began a comparison of last year's consumption with this year's. It turns out that we are generally using less electricity now than we did a year ago. Therefore, in my mind, if I can charge my car without buying any more units than I did last year, then effectively, those units are free because I will not have increased my electricity bill. To help this, I've finally convinced my son to put his computer off at night and at any time that he's away. Computers are quite stiff power sinks, especially when left on 24/7.

Thus, 24 days after acquiring my new car, and even despite charging it overnight after the Bathgate trip, I have one unit in surplus compared to last year. In other words, over these 24 days, I've had to buy one unit of electricity less than I did over the same period last year.

Noises off

The mystery of the missing noise has been slayed.

I was led to believe that the car was designed to make a sound at slow speeds to warn pedestrians of its proximity. I was damned if I could find it. There is a switch to the right of the steering wheel that suggests its purpose is to allow the sound to be turned off but it seemed to have no effect. What sound was I expecting? A Spitfire Merlin engine? A Ferrari V12? A petrol-powered Nissan Note? Some folk I spoke to laughingly imagined that it might be possible to hack the car's electronics and install custom sounds. I'll have a Saturn V lifting off, if you don't mind!

Then a friend who was standing outside the car mentioned that as I manoeuvred into a parking space, the car was making a faint high-pitched whining noise. This I put down to being as a result of the power switching to the motor. Today, as I drove around a car park looking for a space with the window down, I thought to press the switch. Silence! At slow speeds, the car really is silent. The quiet whine is purely artificial and can be switched on and off. It is known as "Vehicle Sound for Pedestrians" or VSP. To my ears, it is at an incredibly low volume.