Electric Plugin Hybrid Cars Environment Friendly City Switch

Not sure how practical that is - as far as I know PHEVs have a relatively short fully electric range - often only a few tens of miles (as the additional weight of the engine limits the amount of battery it can carry), so the ICE will be needed to cut in automatically when the battery becomes low - whether your in a low emission zone or not. So while some people could run without the ICE for 100% of the time inside the LEV, many others could only manage 80% or 60% or 40% or less (say those who do a decent daily mileage within the zone or visit multiple zones in the same day). Even those that mostly manage 100% could be caught out occasionally (e.g. during cold weather where the heating drains the battery faster than usual). So where could you draw a line between grant and no grant? Or have some massive administrative system to  pro-rata things?

I see PHEVs are a short term thing anyway - they're only a quick fix to give additional range to EVs - and are a bit of a botch - having to carry the additional weight of a useless engine around in electric mode and the extra weight of the batteries in IC mode - it's never going to be an efficient solution. As better batteries and more charge points appear, range anxiety is becoming a thing of the past anyway, so I see PHEVs fading away over the next decade or so. Not much point in building a huge system that would be obsolete soon after it was completed.

   - Andy.

Why would the government want to pay people to drive into cities?

CliveS said:

Vehicles without this switch including vans should not receive a grant,

The grant is related to the reduction of greenhouse gas emissions, so whether it's in a city or not is irrelevant. If you want to suggest that city clean air charging should be linked to this then that would be a better argument. But I agree with Andy, it's really not the biggest problem right now. 

We did buy a PHEV to replace my wife's petrol car, because we live in a relatively remote rural area so we're either driving short distance fully electric or considerably longer distances where, as Andy says, charging is currently a pain. (Hopefully sense will prevail and the amount of charging will improve.) But we found when buying ours that PHEVs are rare beats, very few manufacturers are bothering to make them now as they are not the right vehicle for most people. In the SUV class we were looking for there was basically a choice of one, and even that one is no longer sold in the UK as there was seen to be no market for it. Which given that SUVs must be about the most popular class of car now tells us something!

There's a really good way to reduce particulate and other emissions in cities, which is to improve public transport... (I know people can say "you would say that, you work in the rail industry". I would turn that round and say that I work in the rail industry because I feel it's potentially beneficial to society.) Wrote that before Simon posted his much neater sentence! 

Does that mean that if I live in a town, but sometimes drive to a city, then the PHEV must run on petrol or diesel all the time to keep enough charge in the battery in case I enter the boundary of a city?

Surely your idea makes pollution everywhere else worse just so that cities can have cleaner air.

Instead, the UK government is offering grants only to battery only vehicles.  That way they produce less noise and pollution in cities, towns, villages and everywhere in between.

Simon Barker said:

Surely your idea makes pollution everywhere else worse just so that cities can have cleaner air.

Which to be fair is exactly why London for example has its low emission zone, particulates for example are more of a risk in built up areas than in open countryside (as I understand it partly due to the concentration of people, partly to the larger amount of time cars are idling in traffic jams). So targeting ICE reduction in cities does make sense. But of course the particular proposal in this thread would make no net difference to greenhouse gas emissions.

Similarly to your point I did initially find it bizarre that I have to pay for my 50mpg car in the London low emission zone, whereas my wife's previous 25mpg 4x4  - a much higher greenhouse gas emitter - was exempt. But the point was that mine is a diesel, so potentially has higher particulate emissions, which is the immediate risk in a city. 

I'm looking forward to going fully electric when I retire soon - unfortunately for work my car has to be able to make the occasional 150 mile round trip to the station or 200 mile round trip to the airport. Which should be ok in an electric now, but would be really annoying if it wasn't. Once I retire we'll be fine if I have an electric for my local driving, and we can use the PHEV for longer journeys. The the next question is how many solar panels we can get on my workshop roof (our only south facing roof sadly) to help with the charging...

Andy Millar said:

The the next question is how many solar panels we can get on my workshop roof (our only south facing roof sadly) to help with the charging...

And as soon as you have them you'll want the early & late sun from the E & W facing surfaces, and maybe up-sizing the battery to hold a whole day's use. (personal CPD from year one of solar, panels are now cheap)

The ULEZ limits are based on NOx emissions.  That's why it's Euro 4 for petrol cars but Euro 6 for diesels.

My diesel Land Rover is Euro 5.  It has a DPF fitted and should never emit black smoke from the exhaust.  But the NOx emissions are too high for the ULEZ.

The ULEZ charges are doing their job when it comes to my driving.  On the rare occasions I need to go to London, the Land Rover stays at home, and I drive my electric Renault instead.

The only time it ever really affected me was when I was staying with my sister while we sorted out our mother's arrangements, my sister lives 0.5 a mile inside the North Circular. So at that time if I could have found a safe space to park on the other side I could have avoided it altogether. But I have to say, the system does work very intelligently, the actual amount I got charged was negligible due to the tiny amount of driving I was doing in the zone.

I struggle to drive in London these days anyway despite having learned to drive there, having lived in Cornwall for over 30 years I'm just too polite now. I need to keep reminding myself of London Rules: "If your bumper is in front of their bumper you have right of way". (Cornwall Rules are that if two or more cars approach a junction simultaneously then you all sit looking at each other indefinitely. Except tractors, which have right of way at all times.)

Philip Oakley said:

And as soon as you have them you'll want the early & late sun from the E & W facing surfaces, and maybe up-sizing the battery to hold a whole day's use. (personal CPD from year one of solar, panels are now cheap)

Yes, at some point I need to have a beer with my friend who owns an electrical contracting business to start hatching a plan. I'm not sure where they are with solar fitment, but car chargers has now become one of the largest parts of their business. 

AJJewsbury said:

I see PHEVs are a short term thing anyway - they're only a quick fix to give additional range to EVs - and are a bit of a botch - having to carry the additional weight of a useless engine around in electric mode and the extra weight of the batteries in IC mode - it's never going to be an efficient solution.

On the better PHEVs, they don't have an IC mode as such, once the battery has been discharged to a minimum level they switch into hybrid mode, maintaining a minimum state of charge on the battery and continuing to shut off the engine and using the motors when running at low speeds, or low throttle positions. The battery is still used to support the engine to optimise efficiency etc by either assisting or recharging as the engine moves between efficient operating points and during regenerative braking. On some PHEVs the aircon and heating is electric, powered by the HV traction supply and battery, so this continues running even when stationary with the engine off fed from the battery, so overall the battery is always in use.

Also, the battery is always needed on many PHEVs because they operate their engines slightly differently to regular cars, hybrids typically have engines that can operate in a form of Atkinson cycle, adjusting their air intake and fueling, to optimise compression and expansion to improve the thermal efficiency. The engines deliver better efficiency, but produce less power and torque, so rely on the hybrid motors to support the engine under different driving conditions.

Ultimately they can never match the lower carbon footprint of an EV powered by low carbon electricity, but they're actually a pretty impressive piece of engineering. Unfortunately I don't think the marketing divisions of the car manufacturer's do a good job of communicating the benefits and how they actually work.

Andy Millar said:

There's a really good way to reduce particulate and other emissions in cities, which is to improve public transport... (I know people can say "you would say that, you work in the rail industry". I would turn that round and say that I work in the rail industry because I feel it's potentially beneficial to society.)

The difficulty in Britain is the cost, clean electrified mass transit like trams and rail are so expensive to build, either new or expansion of existing networks, that they pretty much rule themselves out due to being unaffordable everywhere except our largest cities. 

Perhaps the hope lies in electric buses, as these become more affordable with falling battery costs and keep the need for new infrastructure to a minimum.