[Julian Thomas]

I'd be really interested to see which model would prefer - there's been lots of chatter about the pros and cons of each method. If we accept that free electricity can't continue indefinitely, which model would you prefer?

 

[fenlander]

If you are voting for per kWh, why?

Because you think it will turn out less expensive, or that it will result in better sharing of a limited resource?

 

[smartie]

It's got to be per kwh as the only sensible option for rapid chargers which should not be allowed to be blocked for hours on end. This would allow charging the appropriate amount whatever the charging capacity of your car.

For slow charging an argument could be made the the charge should be free given the relatively low cost of electricity (with charging limited to say 7kw) but a fee charged that would guarantee a reservation of the charger for a pre-agreed period and then a time penalty if that period is exceeded.

 

[Edd Beesley]

If you are voting for per kWh, why?

Because you think it will turn out less expensive, or that it will result in better sharing of a limited resource?

Because that's how I want to pay for fuel, and how I am used to paying for it.

 

[leave]

It's got to be kWh... you don't pay for petrol by the amount of time you spend parked next to the pump!?

 

[Julian Thomas]

For me, it has to be by fuel consumed in order to then be able to work out cost-per-mile, and then compare with the petrol option. If charging is ever going to be more expensive per-mile, then I won't use the charger and will go to BP.

 

[fenlander]

It's got to be per kwh as the only sensible option for rapid chargers which should not be allowed to be blocked for hours on end. This would allow charging the appropriate amount whatever the charging capacity of your car.

Per kWh is exactly what would cause a rapid charger to be blocked for hours on end. There is no incentive to actually rapid charge on one, or even move away when you are finished under per kWh.

Going back to slow posts... assuming that the same amount of money is required to sustain a network however you bill for it, you'd need to generate the same amount of revenue when charging per kWh as when billing based on time. What that means is that in order to compensate for people who plug-in then go shopping all day, only drawing a couple of kWh, you'll need to increase the per kWh charge to something crazy. I'm guessing that's not what people want either...I'm not going to be happy paying an outrageous amount for electricity just because others like to leave their car plugged in all day.

 

[fenlander]

Because that's how I want to pay for fuel, and how I am used to paying for it.

But electricity is fundamentally different. You can't fill your car up with petrol at home that you generated yourself. It's a different set of economics.

 

[fenlander]

For me, it has to be by fuel consumed in order to then be able to work out cost-per-mile, and then compare with the petrol option. If charging is ever going to be more expensive per-mile, then I won't use the charger and will go to BP.

There is nothing stopping you working out cost-per-mile when paying by the hour. It's your choice how expensive you make the electricity based on how long you want to leave your car plugged in but not charging.

 

[Julian Thomas]

But electricity is fundamentally different. You can't fill your car up with petrol at home that you generated yourself. It's a different set of economics.

Yup - but PHEV drivers have 3 choices of fuel: home electricity, petrol, and public charge post electricity. If you're away from home, you have 2 choices: public charging or petrol. Each time I refuel away from home I work out the cost per-mile of the available charge post, and compare it with petrol (roughly). Time-based pricing makes that near to impossible to compare, given it could be 3-6 hours to recharge, and even on best-case Chargemaster is 15p/mile compared with 10p/mile for petrol.

 

[fenlander]

It's got to be kWh... you don't pay for petrol by the amount of time you spend parked next to the pump!?

No, but try leaving your car on the forecourt while you head off to do some shopping and see what happens.

 

[fenlander]

Yup - but PHEV drivers have 3 choices of fuel: home electricity, petrol, and public charge post electricity. If you're away from home, you have 2 choices: public charging or petrol. Each time I refuel away from home I work out the cost per-mile of the available charge post, and compare it with petrol (roughly). Time-based pricing makes that near to impossible to compare, given it could be 3-6 hours to recharge, and even on best-case Chargemaster is 15p/mile compared with 10p/mile for petrol.

Why 3-6 hours to recharge? Surely that is some specific problem with a particular charging point operator that doesn't make it obvious what the post is capable of? Seems easy to fix...

You've got to factor in your parking charges to that calculation as well in most of the country, so it's almost never as simple as it first appears.

 

[leave]

@fenlander I see your angle, but most people only spend 10-25mins at a Rapid. Barely enough time for a wee and coffee.
If I rapid charge at motorway services, I want to gone ASAP.
If I rapid charge at Ikea, I'm back after 20 mins and move the car elsewhere.
Most car parks have wardens checking tickets. They can slap tickets on idiots who aren't charging too!

 

[Dennis]

I voted for a per kWh because it simplifies comparison of charging in public, if I "sort of" need it vs waiting until I get home. The challenge with this model is in Level 2 (J1772 in the US) charging, where a vehicle will stay connected to a charger and be "done" and the next EV will inadvertently be blocked from using said charger (it is in this instance that charging by the hour helps motivate folks from moving their cars when it IS done charging.)

 

[smartie]

Not if the rapid charger automatically stops charging after 30 mins releasing the charger for the next person.

Chargemaster has tried charging by time and it seems there is very little demand for that, in which case the economics don't work.

Per kWh is exactly what would cause a rapid charger to be blocked for hours on end. There is no incentive to actually rapid charge on one, or even move away when you are finished under per kWh.

 

[Paul]

Per kWh because I pay for electricity I use at home, and used to pay for petrol I used in my car... not for how long I'm in my home with items plugged in or at a petrol pump.

Charging and parking I still believe are two different things, and they should not have to be tied, if you want to, charge me for parking AND then for the charging on top, or give one or the other free, but when it comes to the charging park, I want to pay for what I use (and maybe a "standing charge" / subscription too) but nothing more.

 

[Lee Howard]

If the point of requiring payment for public charging is designed to allocate the resource fairly and to limit hostile encounters, then you have to charge for both kWh used as well as for time. You're trying to do two things: 1) prevent people from needlessly sitting at the charging station for longer than needed, and 2) prevent people from taking more charge than is needed. Hence, you must require payment for kWh *and* time to accomplish both.

AND I would fully *expect* these charges to equate to the same cost as petrol or perhaps slightly more... as this will dissuade PHEV and REX drivers from using the resource needlessly. For those who use public charging as their sole charging method... I'm sorry... that's not the purpose of public en-route charging. Look into destination charging.

 

[Paul]

as this will dissuade PHEV and REX drivers from using the resource needlessly.

Needlessly? Using petrol and all that that entails is needless if there's charge available for electric, surely?

 

[Lee Howard]

Needlessly? Using petrol and all that that entails is needless if there's charge available for electric, surely?

Precisely.

Recognize that the PHEV/REX owner already made a decision with regards to a willingness to use petrol when their battery is used. Whether they use petrol only under dire circumstances or whether they use petrol to avoid en-route charging completely is the variable.

So if the charging cost is monetarily on-par with petrol then the driver has a choice to make based on things other than economics. You don't want PHEV/REX drivers adding to the congestion at en-route charging locations. It's been discussed here and elsewhere numerous times that PHEV/REX drivers should let BEV cars have priority on public charging stations.

Furthermore, I think you're referring to destination charging (to which I am not referring above and should remain free-for-use by intended users). And, sure, PHEV/REX drivers will use that when it's available. However, no practical PHEV/REX driver is going to stop to charge en-route or they would have just purchased a pure BEV, instead.

So, I'm talking about the motorway charging stations more than I am the IKEA charging stations... if that makes sense. I recognize that the OP doesn't make a distinction between them.

For the IKEA-type congestion issues there just needs to be more charging stations. Requiring payment on those is sending the wrong message.

 

[Paul]

Nope, I'm talking about en-route charging and my personal view if it's got a battery and a plug it's entitled to be plugged in and charging, whether it's lugging around an engine or not.