Electric Plugin Hybrid Cars Environment Friendly City Switch

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. 

Interesting.  I do not own an electric car only a bike which runs at 36 volts DC so series connect 4 panels at 12 volts is fine to charge it.

Electric cars have a motor which I assume is 360 volt which is 230 volts time root 2 . So 400 volt DC is a good match.  How many PV panels do we need?

CliveS said:

How many PV panels do we need?

I think the more usual arrangement is to invert the PV output to 230V a.c. and then make it available to a conventional EV charge point (or any other loads or export any excess to the grid). You can then choose the number of panels to give the power you require (again a moving target, as sun intensity isn't exactly constant).

  - Andy.

The bit I'm wondering about is that ideally we'd want to be charging from solar during the day and from our cheap rate midnight to 5am. With a potential to over-ride if needed. Anyone happen to know if there are off-the-shelf solutions with arrangements of power routing and timers to manage that? 

With the PHEV we just charge overnight from the granny lead through a time switch (yes, I did make sure it was sufficiently rated, in fact over-rated, to switch that load!), but when I go fully electric I'll invest in something meatier.

Andy Millar said:

The bit I'm wondering about is that ideally we'd want to be charging from solar during the day and from our cheap rate midnight to 5am. With a potential to over-ride if needed. Anyone happen to know if there are off-the-shelf solutions with arrangements of power routing and timers to manage that?

My Simpson & Partners charger is supposed to be able to do that.  It has a current clamp on the incoming AC supply, so it can work out if I am exporting or importing power.  It can then ask the car to charge at a rate that makes optimal use of the solar.

I have never tried using that.  My old solar system will only deliver 3.4kW at the best of times, and at that power, the sun will have gone down long before the car is charged.

My only use for the current clamp is to stop the charger overloading my 60A supply.

(lost previous rely, Forum playing up, try again..)

There are some charge points that offer a mode that limits the current offered to the car so what's available from the PV system (basically the same idea as the ones that limit so they don't overload the DNO supply, but with the limit set at zero (no import)).

Then there are more sophisticated programmable systems that can be configured to do all sorts of things - e.g. https://www.victronenergy.com/ev-charging/ev-charging-station - including excess solar diversion and making best use of time of use tariffs.

You can even add a battery to the mix, so PV generated is available after the sun goes in and/or off peak tariff rates are in effect available all day and to the whole installation.

Depending on your tariffs though, a much simpler solution might be viable. Some suppliers offer 15p/kWh for exported PV while only charging 10p/kWh or less for off-peak - so it could well pay just to charge the car from off-peak (using your existing timers or the car's app)  and let the PV export as it will.

   - Andy.

(lost previous rely, Forum playing up, try again..)

There are some charge points that offer a mode that limits the current offered to the car so what's available from the PV system (basically the same idea as the ones that limit so they don't overload the DNO supply, but with the limit set at zero (no import)).

Then there are more sophisticated programmable systems that can be configured to do all sorts of things - e.g. https://www.victronenergy.com/ev-charging/ev-charging-station - including excess solar diversion and making best use of time of use tariffs.

You can even add a battery to the mix, so PV generated is available after the sun goes in and/or off peak tariff rates are in effect available all day and to the whole installation.

Depending on your tariffs though, a much simpler solution might be viable. Some suppliers offer 15p/kWh for exported PV while only charging 10p/kWh or less for off-peak - so it could well pay just to charge the car from off-peak (using your existing timers or the car's app)  and let the PV export as it will.

   - Andy.