# IPENZ Electric Car Lectures



## locost_bryan (Aug 18, 2008)

Zevflow said:


> It has some interesting points about electric car conversions as well. What do you think?


They are right that an EV conversion of an existing vehicle is sub-optimal compared to a pure EV design. Fitting the electric components into a vehicle not designed for them, means compromises on packaging and efficiency. Naturally, starting with a clean sheet of paper will allow a manufacturer to optimise the design to get the best use of space, weight, technology, etc.


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## John (Sep 11, 2007)

locost_bryan said:


> They are right that an EV conversion of an existing vehicle is sub-optimal compared to a pure EV design. Fitting the electric components into a vehicle not designed for them, means compromises on packaging and efficiency. Naturally, starting with a clean sheet of paper will allow a manufacturer to optimise the design to get the best use of space, weight, technology, etc.


While this is true at the moment such a vehicle is not available to us so we are stuck with adapting what we can i.e. our sub optimal conversions. I also see these as more of area requiring more effort than a poor choice. The Tesla for instance is a conversion of sorts of a Lotus Elise and other vehicles such as Mitsubishi's MiEV are an adaption of an existing ICE powered car. 

Private individuals don't reasonably have the ability to build cars from the ground up at least not in mass so we are reliant on the mass market manufacturers and what they choose to supply to the market. At the moment an EV market doesn't really exist because EV's are not produced in volume and EV's are not produced in volume because there doesn't exist a market to absorb them. Kudos to GM with the Volt for taking the plunge and Kudos to Tesla motors for inspiring them with their roadster.

One of the things I have considered is if it would be worthwhile building a Locost style EV. Not a Locost converted to electric drive but an EV built from the ground up as an EV using the Locost principles of simplified design and light weight using readily available materials and scrounge-able or cheap components to produce a vehicle that is easily home buildable, affordable, easily customised, and something people could be passionate about driving.


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## Hemon Dey (Jul 31, 2008)

Thanks for posting Zevflow, I had intended to go to the meeting but alas my PDA reminder failed me ... oh how terrible. I hope the talk went well.

I have recently shifted my EV interest towards 3-wheel 2 seater commuter BEVs. I believe this is in-line with the point the paper makes in regard to efficiency, although my consideration is more from a performance point of view. I'm hoping to get much better bang for buck for moving to a custom design, albeit based on plans obtained from a 3rd party (RQRiley) in the first instance. Alas, I'm still waiting for the plans to arrive by snail mail ... 

Despite the reduced efficiency of converted BEVs, I don't agree that this shouldn't be advised, at least even on a small scale. Even a small number of these offsets a significant amount fossil fuels, faster than any new BEV entrant to the country will do. Converting an existing fleet is a feasible alternative if the parts are carefully considered - including the donor car. 

Moreover, although the conversion of the entire NZ fleet of cars (all 2 million of them) will partake in 20% of our generation capacity as it was in 2007, it would be many years before this conversion process could be realised, in which time the generation capacity in NZ would have easily increased. 

This is also not a peak capacity issue as the cars would of course be charged at night where there is reduced demand. You probably wouldn't have to build new generation capacity, you would instead have to find new fuels (ie. for meridian it would be more water for their hydro lakes). The problem here is sustained energy generation, where I would argue that even for the worst case scenario is burning fossil fuels to generate electricity, this is still more efficient than burning it in an automobile because the heat engined utilised for electricity generation can be tuned for efficiency - rather than power output (torque).

I don't want to detract from the point of the paper, in that if you are going to replace a significant fleet of cars, take the path that will bring you greater energy efficiency. This will burden less the system from which you derive that energy from. A converted car typically cannot compete with a custom solution car in these terms. 

However if the custom design car doesn't yet exist and you have the oppurtunity to convert your own car to an EV, the efficiency gain over the fossil fuel equivalent is significant enough that it should still be considered. At the same time, you have extended the life of your older car and are saving energy of having to create another new car.

Regards,
Hemon


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