Dec 27, 2015: Electric Driving Less Than Half The Cost of Petrol

In last week’s Newsletter I wrote about our first week with our new Mitsubishi Outlander Plug-in Hybrid Electric Vehicle (PHEV).

Cintia’s Thoughts About The PHEV

One regular reader commented that they would like to hear what ‘The Boss’ thinks of it, so I asked her to pen a few words…

What do i think about driving the phev?
Well, apart from the obvious that it is great to be able to do our driving around without spending a litre of petrol, it feels like driving a normal car being deaf.
I realise I rely a lot on noise in regards to cars, to the point that I was proposing to Andrew that we conduct a few experiments. One we've already done. We tried to run over Jane, his mother (with her consent) to see if she would be able to hear the sonar noise it is supposed to make. The results were inconclusive. We sort of of heard something as did Jane... We have to do it again. Any volunteers?
The other was to leave the car on and walk away. Will it turn itself off? Like I said I rely a lot on noise. My car just beeps for everything. Beep, you forgot the lights on. Beep, you forgot the seatbelt. Beep, you forgot to take the key. Since this car doesnt require a key to start, just a on/off power button, and it makes no noise I am really concerned about forgetting to turn off the car. I am known for forgetting stuff.
The other noise I rely on is the car itself. I always knew when A was home as Ivan, his little van, has a very particular squeeky noise. It was very useful when I was making this secret project, a birthday surprise book and needed to switch screens before he came into the house. I guess no more secrets...
Jokes apart, the car is great. Just feels like driving a normal car. And I guess for women with children it is good option as it is very spacious and has all sorts of little compartments.
I love watching A trying to beat his own record on 'this new game' of how to drive more economically, decreasing the consumption. Fun driving!

Andrew’s Thoughts

As I get to know it better I’m growing more fond of the PHEV and getting more and more excited about what it can do for us. It really is a pleasure to drive. It’s very comfortable and has every convenience that I could wish for (and much more). I particularly enjoy the regenerative braking. It has paddles on either side of the steering wheel that allow me to easily change the level of regenerative braking. By adjusting these I find I am able to make most trips with hardly a touch on the brake pedal. This means that we’re able to recover every bit of energy that would otherwise be wasted slowing the vehicle down on hills or in traffic and put that energy back into the batteries. It’s really fun to hit the top of the hill between Bowral and Mittagong with 13 km of electric range left in the batteries and get to the bottom of the hill with 17 km of range. Most of all, I like the sound this car makes. When we’re driving slow on electric it’s almost totally silent, there’s just a faint noise that sounds a bit like an electric train accelerating, a bit like something out of Star Wars, that tells me that we’re not using any petrol. The fact that the energy for our short trips comes from the solar panels on our roof gives me a big sense of relief and satisfaction.

Last week I was unable to give any real indication of actual fuel economy because I hadn’t filled the tank yet. During the last week I had to make a trip back to Lander Mitsubishi to have the tow-bar installed and I also drove down to the coast for a pre-Christmas surf with my brother. This meant that I used most of a tank full of petrol which gave me the opportunity to fill it up. Based on my records, on the first tank of petrol, I drove 659km and used 32.09L of petrol. This makes for an average fuel economy of 4.9L/100km.

This, of course, is much higher than the 1.9L/100km listed for this vehicle but is quite a bit better than I expected based on the research I did before buying the car. The rated fuel economy is calculated under specific test conditions that seem to favour electric vehicles. I don’t know exactly what those test conditions are but it must involve a lot of short trips with frequent charging in between. As I wrote last week, this is certainly achievable with the Outlander PHEV, depending on how far you drive and how often you recharge. Last week was a rare one in which I made two trips that were well outside the 50km electric range.

During the same period we also put a total of 30.6 kWh of electricity into the batteries. I’ve already figured out that driving on electric is cheaper than driving on petrol. We are getting a range of about 50km from a full charge of about 9.5kWh. We are paying $0.238/kWh so it costs us $2.26 to go 50km on electric. BUT if we charge the battery during the day [when our solar system is producing excess power and we are getting $0.10/kWh back from Click Energy in the form of a Feed In Tariff (FIT)], our net electricity cost is only $0.138/kWh which means it only costs us $1.31 to go 50km on renewable energy.

By contrast, when we drive on petrol alone, our fuel economy seems to be around 5.5L/100km (based on the fuel-economy gauge in the car). That means it takes 2.75L to go 50km. At our local price of $1.21/L it costs us $3.33 to go 50km on petrol.

These are only approximate calculations but it seems fairly clear that it is less than half the cost for us to drive short trips on electric versus petrol power. PLUS we have the satisfaction of knowing that we are using a renewable energy source. Even when I’m not at home during the day, I can still plug in to charge up knowing that the energy I’m taking from the grid at the job site is being replaced by our solar system at home. I may have to pay the full 24c/kWh for the power I take out at work but I’m still getting 10c/kWh for the power I’m putting in at home so it still only costs me about 14c/kWh.

I’m keeping careful track of how much energy I’m using to charge when I’m not at home. It will be very interesting to see, over the course of a month or a year, if our solar system can provide enough excess power to cover all of our electric driving as well as running our entire house. As you can see if you take a look at our Results Page, we continue to export over three times as much power to the grid as we import from it. Last month we exported 370kWh and only imported 70kWh. This means we had an excess of 300kWh for the month or an average of 10kWh every day. Since it only takes 9.5kWh to completely charge the car batteries, we could theoretically drive up to 50km every day and still have excess power. Most days I don’t drive that much.

The dream for me is to be energy positive with both the house and the car. So far this Outlander PHEV seems to be a great step in the right direction.

p.s. One astute reader pointed out that all vehicles have ‘optimistic’ odometers. In other words the speedo is factory set to show a slightly higher speed than you’re actually doing (no doubt to avoid possible litigation from someone who got fined for speeding when their speedo showed they were ok). This means you don’t travel as many km as your odometer says you do. So, if fact, our fuel economy will be worse than we think it is based on the odometer reading. His advice is to use the odometer check markers along the highway to figure out how far off the reading actually is then apply a ‘correction factor’ to the distance traveled to give you an accurate figure. I haven’t had the chance to do that yet but I will when I can. Meanwhile, since we’re primarily comparing electric driving to petrol driving using the same odometer readings, I think our results are close enough for the moment.