# Are EV conversions economically worthwhile?



## Richard Wood (Jun 27, 2008)

Hi All

I've set up this separate thread on this question of whether EV conversions are economically worthwhile for city commuting in New Zealand as the question was popping up elsewhere. Let's for a moment assume the economics is all that matters (Yes, I know it isn't but this is an exercise!)

Let's say you do an EV conversion for $20,000 on your existing car and it lasts 10 years. Let's say your existing car would have also lasted 10 years as a petrol car - so we've cancelled out a lot of comparative costs. Let's put no value on your conversion time as this is a fun project.

Let's also assume an interest rate of between 6% and 14%. That would be loan repayments of $51 to $71 a week to finance depending on whether you have put it on a mortgage or a personal loan.

With a regular city commute plus weekend driving I would think that an equivalent saving of that sort of money is expected, so from those that claim it is uneconomic, what are the costs that blow out the figures? Am I overestimating savings? Will the battery need to be replaced at huge cost early? 

On the plus side to this calcuation is lower mechnical maintenance costs - what do they amount to? Also there is an expected rising cost of petrol - what savings contribution is that likely to be. I am also imagining the future cost of electricity may be constrained by advances in home electricity generation - do you agree?

Richard


----------



## Duncan (Dec 8, 2008)

Ok 
starting with a 4L/100km car a 25Km commute will save $2,50/day - minus 50c for the electricity - $2 a day
$500 a year
$5,000 over 10 years - no that's no good

50Km commute - $10,000 over 10 years 

100Km commute - $20,000 over 10 years - but I haven't taken interest into account

If you have a 100Km daily commute - a $20,000 conversion will be marginal

- MOVE CLOSER TO YOUR WORK!!! - or change jobs!

Looking to the future - petrol will be more expensive - how much more?

In real terms the most expensive petrol I used was in the 1980's - its cheaper now relative to wages

John Key AKA -the smiling assassin took road user charges off EVs - but he did say it was temporary and would go back on - when??

Now if you start with a more thirsty car (my Legacy) then its better 
8L/100km car a 25Km commute will save $5/day - minus $1 for the electricity - $4 a day
$20 a week -

a 50Km commute is $2000 a year - that would repay the capital 

5% on 20,000 is $1000 a year

So a 75Km commute would be on the cusp - 

That's still a long way to commute


----------



## CrazyAl (May 9, 2011)

Richard Wood said:


> so from those that claim it is uneconomic, what are the costs that blow out the figures? Am I overestimating savings? Will the battery need to be replaced at huge cost early?


What parts do you plan to put in?
For example, if you use Lead Acid batteries, they have a shorter life than Lithium Iron Phosphate batteries.
What range do you expect to get?



Richard Wood said:


> On the plus side to this calcuation is lower mechnical maintenance costs - what do they amount to?


If you use a brushed DC motor, brushes need to be replaced, but that is not really a big issue. If you use a pot box, they can wear out.
You may have to replace the bearing on the electric motor - no big deal.

However, compared to a gas car, you won't need to change or do:


oil filters;
oil;
fuel filters;
air filters;
spark plugs;
valve clearance adjustments (depends on motor);
exhaust systems;
catalytic converters;
oxygen sensors;
spark leads / coil packs;
seals like rear main seals etc;
head gaskets;
intake manifold gaskets (on some cars, you have to take the intake manifold off to get to the spark plugs);


----------



## Richard Wood (Jun 27, 2008)

Hi Duncan

Those milage figures look a little light for the city commuting example we're talking about, perhaps based on modern cars in ideal conditions? New Zealand cars average 10l/100km and once we focus in on a more typical 10+ year old car in city commuting with hills and stop/start driving it can only get worse. For example in my Civic, I travel a 30km round trip to work, which is pretty low for Wellington commuting from north or east. Once we include evening trips and getting around in the weekend dropping and picking up kids, going to shops and markets etc, I'd fill the tank once a week at $50-$70 a pop. When I used to use a Subaru it was more like $80-$100. Happy to hear other real life examples but I expect that is normal for the bigger city dwellers outside of the inner suburbs (Inner suburbs tend to have good bus options anyway). I assume you're joking when you say move closer to work or change jobs, given the higher cost of housing and difficult job market in the cities  .

Crazy Al
Great list of all the costs that can be avoided. It would be interesting if anyone has a guestimate of what that might amount to over 10 years for a typical 10+ year old car. As for the other question, this is an exercise for those interested in the maths, but it's on the basis of a $20,000 expenditure on a car that will do typical city commuting. Let's say it's Lithium batteries and the ability to do 50km a day.

Richard


----------



## Duncan (Dec 8, 2008)

Hi Richard

You need to move to Southland - cheap houses and short commutes

I thought my Legacy would be about the worst - 9L/100 - I can pick up something small and cheap dead easy

As far as the maintenance costs - my 12 year old Legacy has cost a total of $250 over the last three years 

My previous Legacy died at 350,000K and 16 years old - and I could have kept it going but I wanted the suspension for my project


----------



## Richard Wood (Jun 27, 2008)

Hi Duncan

I'm sure Southland has a lot to offer (looking out at the Wellington weather).

You've got off lightly with your maintenance costs, but I guess that is because of the short commutes. My 12 year old Legacy has had a few thousand spent on it and I'm pretty much keeping it only for long trips these days.

Cheers
Richard


----------



## Richard Wood (Jun 27, 2008)

Here is an interesting related thread on an Australian forum. 
http://forums.aeva.asn.au/forum_posts.asp?TID=525&title=6000-ev

If a car can be converted at A$6000 (not sure if that includes the coupling) then that makes things interesting and I was surprised at the idea of sticking to AGM batteries to reduce the up front cost despite acknowledging lower long term costs for Lithium. I guess a point here is that reducing up front cost can reduce risk if it ensures earlier payback.

Thoughts on this?

Richard


----------



## Ziggythewiz (May 16, 2010)

Reducing upfront cost does not ensure earlier payback, reducing total cost does.

If you're replacing your lead pack every two years, that will significantly cut into your ROI, not to mention the time spent dealing with it. And yes, my car was converted for $6000. All the batteries have been replaced once, and while I have made little ROI because of that, I expect most of them to last at least 18 mo more, so all that use is ROI. With lithium the $$$ in would have been higher, but my net ROI so far would have been much higher, with no significant further expenses for many years to come.

Along with your original question, a conversion shouldn't be compared just to an old vehicle, but to a new one as well. "*Are new automobile purchases economically worthwhile?" *I don't know about NZ, but millions of people around the globe answer Yes every day.


----------



## Richard Wood (Jun 27, 2008)

Ziggythewiz said:


> Along with your original question, a conversion shouldn't be compared just to an old vehicle, but to a new one as well. "*Are new automobile purchases economically worthwhile?" *I don't know about NZ, but millions of people around the globe answer Yes every day.


To a new electric or a new petrol car? A conversion would easily appear to trump a new electric on purchase cost alone since we're not including the labour cost of conversion. A conversion vs a new petrol car is another question, but it's hard to see how a new petrol car can compare in the context of New Zealand's cheap second hand import market.
Either way, happy to hear about the numbers that challenge this thinking.
Richard


----------



## Ziggythewiz (May 16, 2010)

I mean compared to a new petrol...what a 'normal' person would be buying. 

Obviously a conversion won't compare well to a used ICE short term, but if you start with a relatively new car you can expect it to not need any major work (ie engine rebuild) for the next 10 years. A used ICE is guaranteed to need work, not to mention oil, plugs, etc.


----------



## Nick Smith (Oct 26, 2007)

I have just had my wifes 2003 golf serviced with cambelt replacement, water pump, replaced leaking thermostat housing, oil change and engine flush and it hit me for 1700 bucks. Up to now we had only replaced the rear brakes for about 250 and then more recently the fuel pump packing in for 800 bucks down the pan. It is now starting to cost us! Converting this car now would likely save us a packet in these sorts of future costs but who can quantify this for any particular car. My old mans sigma only packed in at 350k because the water pump failed. The only major maintenance i ever remember was the cam belt change every 100k.

The value might be in converting a near new vehicle (2-3 yrs old) where the initial depreciation has been hit but the car is still in very good shape and the engine, exhaust - fuel pump - etc is worth something to others. Compared to the 60k for a leaf of imiev you could possibly drive away with a very good car for 45k ( if u do the work yourself) albeit not an oem but still near new and electric. Ok, but when compared to the petrol version of the same car though, 20 to $25k in conversion costs and time could buy approx 10 years of fuel. I suppose the value is all in what you actually compare the EV with.


----------



## nucleus (May 18, 2012)

Are EV conversions economically worthwhile?

No. Every calculation I have seen says no. I have yet to see one that includes opportunity costs, which would make the comparison even worse.

Nucleus


----------



## Ziggythewiz (May 16, 2010)

That's a pretty generic statement. MY opportunity cost is driving my minivan at a cost of $4-5/day vs $0.30 electric. I save $100 a month, and what money I do/have spent goes to American or Chinese companies, not middle eastern terrorists. How is that not worthwhile?


----------



## nucleus (May 18, 2012)

Ziggythewiz said:


> That's a pretty generic statement. MY opportunity cost is driving my minivan at a cost of $4-5/day vs $0.30 electric. I save $100 a month, and what money I do/have spent goes to American or Chinese companies, not middle eastern terrorists. How is that not worthwhile?


You counter my "generic statement" (necessary because I was making a general statement) with a red herring statement. If you feel that your conversion is economically worthwhile state your numerical case. Where your money goes is a red herring side issue. The US doesn't get a majority of it's oil from the middle east BTW.

I think EV conversions are great, but they are clearly not economically worthwhile compared to ICE vehicles. Which is fine, those of us on this forum don't mind paying the premium. But it is disingenuous to tell someone that you save money by converting a vehicle to electric propulsion.


----------



## Ziggythewiz (May 16, 2010)

Hey stupid. Read my post. The numbers were there. If you subtract my EV cost from my opportunity cost the difference is ROI.

As for where oil comes from, it doesn't matter where most of our oil comes from. As long as any of it comes from the middle east we will waste $trillions$ protecting it.


----------



## nucleus (May 18, 2012)

Ziggythewiz said:


> Hey stupid. Read my post. The numbers were there. If you subtract my EV cost from my opportunity cost the difference is ROI.
> 
> As for where oil comes from, it doesn't matter where most of our oil comes from. As long as any of it comes from the middle east we will waste $trillions$ protecting it.


Hey smart. Read your post. The numbers were not there. To know your opportunity cost we need to know the cost of your conversion. 

You might want to look up the economic definition of opportunity cost. The OP was asking an economic question and you bring in politics and insults.


----------



## Quasar (May 5, 2010)

Just discovered this forum, I thought EVs in NZ were a non-event! Except for mine, of course. Which is a 1988 BMW 318 (E30) with a 135 cell LiFePO4 battery (3P, 45S), two Advanced DC L91 motors in tandem, and a Cougar 500A controller It'll do a bit over 100 kph (130 if I connect the motors in parallel) and travels 100 - 130 kms on a charge. Quite a practical round-town vehicle, but the range drops to about 80 kms driving at 100 kph.
It cost me approx $21,000 to build, about $13,500 for the Li cells.
The battery takes about 18 units of electricity for a full charge and if that takes me 100 kms, it costs about 4 cents per km, assuming electricity at 22 cents per unit. If the battery lasts 2000 cycles (CALB claim more) and each cycle is 100 kms, then 200,000 kms for $13,500 or 6.75 cents per km for an all up running cost of about 11 cents per km. Of course there are other costs such as tyres, brakes, rego, insurance, but they are the same as for a petrol driven thing, so ignored for the purpose of comparison. I'm ignoring brush replacement, they ought to be good for lots of kms and don't cost that much.
The petrol driven version does about 10L per 100 km - say about 21.5 cents per km for fuel. Other costs are servicing (oil, filters, belts and so on), typically about $500 every 10,000 kms, so 5 cents per km for a total running cost of about 26 cents per km.
There you go then, my EV saves me 15 cents per km over the petrol driven equivalent and you don't need to be a mathematical genius to work out that it'll take 140,000 kms before I break even! If my EV lasts for 200,000 kms, I'll save $1050 - whoop-de-doo!
But hey, if you add in the $50,000 worth of fun I had building it and driving it, you can see that it is a huge economic benefit.


----------



## CrazyAl (May 9, 2011)

Quasar said:


> Just discovered this forum, I thought EVs in NZ were a non-event! Except for mine, of course. Which is a 1988 BMW 318 (E30) with a 135 cell LiFePO4 battery (3P, 45S), two Advanced DC L91 motors in tandem, and a Cougar 500A controller It'll do a bit over 100 kph (130 if I connect the motors in parallel) and travels 100 - 130 kms on a charge. Quite a practical round-town vehicle, but the range drops to about 80 kms driving at 100 kph.
> It cost me approx $21,000 to build, about $13,500 for the Li cells.
> The battery takes about 18 units of electricity for a full charge and if that takes me 100 kms, it costs about 4 cents per km, assuming electricity at 22 cents per unit. If the battery lasts 2000 cycles (CALB claim more) and each cycle is 100 kms, then 200,000 kms for $13,500 or 6.75 cents per km for an all up running cost of about 11 cents per km. Of course there are other costs such as tyres, brakes, rego, insurance, but they are the same as for a petrol driven thing, so ignored for the purpose of comparison. I'm ignoring brush replacement, they ought to be good for lots of kms and don't cost that much.
> The petrol driven version does about 10L per 100 km - say about 21.5 cents per km for fuel. Other costs are servicing (oil, filters, belts and so on), typically about $500 every 10,000 kms, so 5 cents per km for a total running cost of about 26 cents per km.
> ...


BMW E30s are a nice car (I'm tempted to get one for conversion).
Do you have any pictures of your EV, particularly the layout etc? Would I be correct in assuming that your car is not running a transmission and it is direct drive?

Thanks


----------



## Quasar (May 5, 2010)

CrazyAl said:


> BMW E30s are a nice car (I'm tempted to get one for conversion).
> Do you have any pictures of your EV, particularly the layout etc? Would I be correct in assuming that your car is not running a transmission and it is direct drive?
> 
> Thanks


That's correct, no gearbox or clutch, just direct drive. I originally had a 1000A controller (blew up, sadly) and that gave heaps of torque and a good top speed with the motors in parallel (electrically). Since changing to a 500A controller, I had to wire the motors in series to get the starting torque back up which means the top speed has dropped as each motor only sees half voltage. It still does over 100 kph though, so I'm not concerned.
If you look here:

http://forums.aeva.asn.au/forums/forum_posts.asp?TID=1446&title=nevillehs-bmw

you will see the whole tale!

Its also on evalbum but I can't remember the exact link.


----------



## evnz (Jul 24, 2010)

Duncan said:


> Hi Richard
> 
> You need to move to Southland - cheap houses and short commutes
> 
> ...



A work mate had one it spent 4 of the 6 months in the shop geting fixed and it was southland 
As far as cost goes if the petrol motor dies you get a replacement motor or car with a ev you keep the motor etc and get a new body


----------



## CrazyAl (May 9, 2011)

evnz said:


> As far as cost goes if the petrol motor dies you get a replacement motor or car with a ev you keep the motor etc and get a new body


Well said. Also, an off the shelf Electric Motor is not specific to a body.


----------



## John (Sep 11, 2007)

CrazyAl said:


> Well said. Also, an off the shelf Electric Motor is not specific to a body.


So what determines the economic life of an ICE car is the durability of the mechanicals and a good proxy for that is how many kilometers it has traveled and what determines the economic life of an EV will be the durability of the vehicle body with the possibility of reincarnation into subsequent bodies. What will kill the body of a vehicle besides accidents, corrosion, and wear is fashion. A vehicle body could be built to be extremely durable but as it becomes old fashioned and doesn’t have the latest widgets it is depreciated in value. Just as electronics devices are depreciated in value and eventually discarded while still perfectly functional though cars are more utilitarian than electronics. When battery replacement time comes around would a person put their new $10k battery in their old $1500 vehicle with its worn upholstery and outdated features or would they opt for something more up to date? Will batteries determine the economic life of an EV? Is it reasonable for the batteries to compose 90% or more of the value of an old vehicle? I think the industry will try and make the batteries proprietary so that when the batteries die so will the entire vehicle. This way obsolescence is built in otherwise cars could last a very long time and not everyone is a slave to fashion. Remaining life in the batteries becomes very important to determining remaining value. The industry will need a very robust measure to demonstrate remaining battery life expectancy in EV’s.


----------



## albo2 (Oct 4, 2011)

probably slightly off topic but designed and perceived obsolescence is something that needs to be stopped if we are going to move into sustainability, I think the car industry is in for a big shake up when people start buying and driving the Tesla model S this car is all aluminum, If I could afford I wouldn't mind driving that for the rest of my days


----------



## Duncan (Dec 8, 2008)

albo2 said:


> probably slightly off topic but designed and perceived obsolescence is something that needs to be stopped if we are going to move into sustainability, I think the car industry is in for a big shake up when people start buying and driving the Tesla model S this car is all aluminum, If I could afford I wouldn't mind driving that for the rest of my days


Cars today are a ton better than they used to be - BUT - I don't think that process is finished
In 10 years I hope that self drive cars will be available - and in 20 years they will be in my price bracket

Electric - self drive car - that could be a forever car


----------



## Quasar (May 5, 2010)

Jeez, if I lived in Southland, the heating bills would preclude me from owning a car!
(-


----------



## Duncan (Dec 8, 2008)

Quasar said:


> Jeez, if I lived in Southland, the heating bills would preclude me from owning a car!
> (-


I kind of agree and not - 
This is the warmest country (in winter) that I have ever lived in

Much warmer than England, Scotland or Mid-West USA (Indiana)

WITH THE COLDEST HOUSES!!!

We are 20 years behind the times - people live in Canada and Germany in houses that don't need any heating!

Spend just a few more dollars on insulation and decent double glazing 
(NOT ALUMINIUM)
And you can have a warm house on a very small heating bill,

When I was in Christchurch I had a house built - double the standard insulation, underfloor heating, solar heating panels, UPVC windows

Lovely - then I had to move - did the extra comfort make it sell easily?

What do you think?


----------



## Quasar (May 5, 2010)

Yes, you are quite right. The houses in this country seem to have been built for a climate of at least 15 deg further North!
I live in Tauranga which probably has the mildest climate of anywhere in the whole country, but it can still get damn cold in the winter and pretty warm in the summer. One of the things I looked for in buying this house was insulation and this one has insulated walls, ceilings and floors. The architect paid a lot of attention to taking advantage of the natural heating and cooling aspects with the result that we can heat and cool the place quite efficiently.
I have lived in England and Canada, so I was much more aware of how a house should be built than is the average New Zealander.


----------



## John (Sep 11, 2007)

Duncan said:


> I kind of agree and not -
> This is the warmest country (in winter) that I have ever lived in
> 
> Much warmer than England, Scotland or Mid-West USA (Indiana)
> ...


Add a little pasive solar design and thermal mass and reduce the heating bill further. You can use aluminium as long as it has a thermal break.



Duncan said:


> When I was in Christchurch I had a house built - double the standard insulation, underfloor heating, solar heating panels, UPVC windows
> 
> Lovely - then I had to move - did the extra comfort make it sell easily?
> 
> What do you think?


When it is buried in the walls people don't see it. Little value is attached to it. This is why the government needs to mandate better minimum standards. Also the Homestar rating for houses was an attempt to make it more visible to prospective home owners. Getting a certified Homestar rating might be a way of realizing some gain from selling on a super insulated house. Getting an R value over 3.0 for the walls would probably require thicker walls which would add significant cost to a new home. Often the people who suffer aren't the ones profiting from the houses. A lot of houses are built by development companies and by property speculators and are often bought as investments and tenanted. Who in that housing development and use chain cares about anything other than profit besides the tenants? So they are built for minimum upfront cost with little regard for running costs. That is someone else’s problem. Even if it only cost an extra $100 to install better insulation they wouldn’t do it.


----------



## Duncan (Dec 8, 2008)

_*You can use aluminium as long as it has a thermal break.

*_Only aluminium with a thermal break is even more expensive than UPVC! 
And still does not have the wind proof and tilt n turn features
UPVC usually meets the European standards - howling gale outside - no draft inside

Tilt n turn
Each window can open from the bottom a small amount for ventilation
or open like a door from the side
It makes every window a fire escape


----------

