A Queensland-based BMW i3 owner has shared details of the superbly low running costs for his electric vehicle, coupled with a rooftop solar system, after two years of ownership.
Chris Cathcart shared his experience on Facebook to the Queensland branch of the Australian Electric Vehicle Association, saying that he hoped the statistics and experience of owning the BMW i3 would be of interest to the group.
“I really love driving the car and take any excuse to go out and explore this great country. We live about 35 minutes north of Brisbane. Whether it is a holiday to Cairns or just taking a different route to the places we go to often. It’s just a pleasure to drive in the comfort & quiet of an electric vehicle,” writes Cathcart.
“The feeling really doesn’t get old. Every time we take someone for a spin, they are amazed at the power & torque, plus how smooth & quiet it moves. The hardest thing about our ownership so far, has been finding time to keep it looking clean. Because we use it so much.”
What is most impressive is the savings in fuel costs. According to Cathcart, he has done nearly 100,000km driving in the two years since buying the $70,000 BMW i3, and he says he has spent only $32.31 on power.
“We’ve been the proud owners of our was new, 2018 BMW i3s BEV for 2 years now and thought it would be a good time to give everyone an update. So here are some statistics that might be of interest to the group,” writes Cathcart.
“We have now driven 94,320km, using 13,142kWh of power, costing us a mere $32.31. That’s an average of 13.95kWh per 100km,” said Cathcart, noting that he is tracking kWh put into the car not kWh used by the car, which says its lifetime usage is 12.8kWh/100km.
Compared to around $14,500 in fuel costs based on average passenger car fuel consumption (10.8 litres per 100km based on ABS statistics released in 2019), and around 143c per litre for unleaded petrol in 2018-2019, Cathcart’s savings are substantial.
He attributes the very low cost of charging his electric vehicle to the Zappi charger, which cost around $1,300 and allows the electric vehicle to charge with power harvested straight from the sun, via his rooftop solar system.
“So why are our power costs so incredibly low? This is because we have invested $1,300, for a Zappi charger at home, so we can use our solar system to nearly exclusively charge the car, while at home,” he said.
Of course, there have been other costs – including registration, maintenance and incidentals such as cables. In two years of ownership, Cathcart has only needed to have his BMW i3 serviced twice. In total (and excluding the cost of the Zappi charger) he says ownership costs total a little over $7,000.
“We’ve also just got the car it’s second scheduled service, which was just a visual inspection service, costing us $88. So total servicing cost is now $301, plus $1070 for 4 new tyres. That’s all the running costs for the first 2 years,” he writes.
Adding in the one-off cost of the Zappi, which was installed for around $100, total costs come to nearly $8,500.
He compares the fuel costs of the family’s previous vehicle a 2013 VW Golf that for fuel, servicing and tyres cost more than $9,000, and which due to known gearbox issues had little value when it came to resale.
“Comparing that to our last new ICE car, a 2013 VW Golf. In that same distance we spent $7,100 on fuel & $2,015 on 6 separate log book services & tyres,” he says.
Of course, all this is notwithstanding the installation of Cathcart’s 28.8kWh solar system, which has been upgraded incrementally over time.
We caught up with Cathcart to find out how his family’s rooftop solar comes into the picture.
“We just recently upgraded for the third time – we’re at 28.8kW and 21.6 in inverters,” he says, adding that in two years the system has exported 20MWh and imported only 3.3MWh.
“The last step was a minor upgrade to add a LG 10kW battery because of government rebate and loan in Queensland.”
Cathcart says in total, the system including an upgrade to 3 phase to reduce wastage has cost around $36,000.
“It sounds high, but it’s about $36,000 – the biggest waste of money is the battery side of it. Originally the solar system was 1 phase and 10kW with 8kW inverter – we had quite a bit of wastage because of the 5kW export limit.”
By going to three phase, Cathcart says the export limit is increased and there is less clipping of power sold back to the grid, meaning the system gets paid back more quickly.
“Now we can export triple the power when the car is not charging – there’s a substantial passive income,” he says, adding any energy left that would be clipped can be stored in the car battery instead.
He says it is tricky to predict exactly how quickly the upgraded system will be paid off, as feed-in tariffs may change over time, but that savings from fuel are also a consideration.
“From day one we were looking at around 5 years, but it’s now about three years. It will probably end up taking a little bit longer but at the same time if you factor in what the car is saving, we’ve saved fuel costs too,” he says.
“The car obviously costs more but it is nicer car than the average car, and obviously the servicing is minimal – the other thing is depreciation will be a bigger factor.”
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Bridie Schmidt is lead reporter for The Driven, sister site of Renew Economy. She specialises in writing about new technology and has been writing about electric vehicles since 2018. She has a keen interest in the role that zero emissions transport has to play in sustainability. She has participated in podcasts such as Download This Show with Marc Fennell and Shirtloads of Science with Karl Kruszelnicki and is co-organiser of the Northern Rivers Electric Vehicle Forum.