Is overnight charging cheaper? If not, why the timer?

[endeavour]

Hi, just got my Outlander PHEV gx4h in Atlantic grey. Had a standard 16 amp charging point fitted by chargemaster and have started charging the car whenever it needs the juice.

What I don't get is that since both the British Gas and Chargemaster polar charging points require a phone signal and connection all the time they can't be connected to my economy 7 electricity meter and therefore have to be on the standard pipe (yes, I am not an electrician).

My electric supplier is EON and it seems there is either the standard price for electricity any time of day, or the economy 7 price. It would seem then that there's no difference in the cost of overnight charging and using the timer app than there will be during the day or peak times.

Is anyone having a similar experience?

 

[maby]

If you are on an Economy 7 type tariff, then all the electricity you consume at night is on the cheap rate. The meter will usually have a switched circuit that is only on while you are on cheap rate - this is used to power storage heaters if you have them installed.

 

[endeavour]

Thanks for the reply. What is confusing is that the charge point engineers seem to have in it their heads that the charging point "can't be fitted to your economy 7" because the charge point needs power all the time to send signals back via an O2 signal.

What they actually mean is that they can't run the charge point off your economy 7 circuit board and trips because it won't have power all the time, so they have to either run it from the standard circuit board or install another board just for the charging point. I would think this will be a common question from EV owners.

 

[user 417]

If you are on an Economy 7 type tariff, then all the electricity you consume at night is on the cheap rate. The meter will usually have a switched circuit that is only on while you are on cheap rate - this is used to power storage heaters if you have them installed.

Really? If you have two meters and one is for Economy 7 only, how do they apportion the electricity used on the other meter to day or night tariffs?

 

[tarq]

Economy 7 is the 'only' electric available at night, providing you have an economy 7 meter.

The time clock switches your tariff at a set time, usually between 1am -8am in summer & 12 to 7am in winter.

We have had it for years, as we are all electric & run storage heaters & immersion at night, also do d/washing & washing & any other things we can fit in when it's cheap rate.

The BG guys that fitted our charge point didn't seem to understand about 'eco 7' so I just kept quiet and let them get on with it, and it works! :lol:

 

[TerryB]

From Wiki

The night storage heaters and hot water boilers are generally on a separate circuit which is only switched on when the night rate is activated, although any electrical appliance on an ordinary circuit during this period also runs at the lower rate of billing, such as a dishwasher or washing machine set to start using a timing device. Some such machines have timers built-in partly for this purpose, for example Bosch dishwashers.

In newer houses, a digital meter automatically switches to record both ranges. The wiring in the house is rarely different for Economy 7. Many consumers will however choose to set devices such as storage heaters and water heaters to turn on during the hours of Economy 7 to save money. Few houses now have devices controlled solely by the timer on the electricity meter itself.

The specific times when Economy 7 applies vary between different regions and at different times of year. Typically the seven-hour period starts at 1.30am during British Summer Time and 12:30am during Greenwich Mean Time (winter).[4] Some regions use radio teleswitching to control consumers' systems and vary the timing. This uses data superimposed on the 198 kHz BBC Radio 4 long-wave signal.

Simple eh!

 

[greendwarf]

From Wiki

The night storage heaters and hot water boilers are generally on a separate circuit which is only switched on when the night rate is activated, although any electrical appliance on an ordinary circuit during this period also runs at the lower rate of billing, such as a dishwasher or washing machine set to start using a timing device. Some such machines have timers built-in partly for this purpose, for example Bosch dishwashers.

In newer houses, a digital meter automatically switches to record both ranges. The wiring in the house is rarely different for Economy 7. Many consumers will however choose to set devices such as storage heaters and water heaters to turn on during the hours of Economy 7 to save money. Few houses now have devices controlled solely by the timer on the electricity meter itself.

The specific times when Economy 7 applies vary between different regions and at different times of year. Typically the seven-hour period starts at 1.30am during British Summer Time and 12:30am during Greenwich Mean Time (winter).[4] Some regions use radio teleswitching to control consumers' systems and vary the timing. This uses data superimposed on the 198 kHz BBC Radio 4 long-wave signal.

Simple eh!

And just to complicate matters further, EDF have a variant on this called 20:20 tariff which gives me "cut-price" electricity (20% discount) between 9pm & 7am weekdays and all weekend. All done through a single meter.

 

[user 417]

Simple eh!

Sounds simple, but I'm still not sure I fully understand.

A meter simply records the number of kWh used. It records this at all times of day, it can't record a different amount at different times of day. So it needs a special meter that records the number of kWh into different pots at different times of day. You can't have E7 without a special meter, surely? I have a rental property with an E7 meter fitted and it has two different counters on it, I always assumed that they related to the two different circuits, since there are outlets previously used for storage heaters that only go live at night. I hadn't realised that they both gave the discount rate. If I had known that I wouldn't have bothered having two immersion heaters installed.

 

[maby]

Simple eh!

Sounds simple, but I'm still not sure I fully understand.

A meter simply records the number of kWh used. It records this at all times of day, it can't record a different amount at different times of day. So it needs a special meter that records the number of kWh into different pots at different times of day. You can't have E7 without a special meter, surely? I have a rental property with an E7 meter fitted and it has two different counters on it, I always assumed that they related to the two different circuits, since there are outlets previously used for storage heaters that only go live at night. I hadn't realised that they both gave the discount rate. If I had known that I wouldn't have bothered having two immersion heaters installed.

The original E7 meters were mechanical devices with two separate counters for the two charging rates plus a electromechanical timeclock. These days, suppliers are moving towards the "smart meters" which are electronic devices and can handle almost any combination of tariffs. The switched circuit for storage radiators is effectively a bonus - not really a basic feature of an E7 meter.

I was making enquiries about going onto E7 with EDF and British Gas. BG told me that they no longer fit E7 meters - they will only offer E7 tariffs to consumers with smart meters and they cannot guarantee a smart meter installation. We would first have to switch supplier to BG, and hope that they schedule us for a smart meter installation immediately - then we could be put onto an E7 tariff.

 

[user 258]

Npower will not change a standard meter to an Eco7 meter wither. I asked them and they said no.
Kind regards,
Mark

 

[Poins]

We're with Eon, and they were happy to swap our meter to a dual-tariff meter that would enable us to switch to Economy 7. For most people E7 isn't worthwhile because the daytime tariff is more expensive but we also have solar panels and that reduces our daytime consumption. I reckoned that with likelihood of overnight charging, E7 will probably give us a saving. Shopping around on the price comparison sites, I found another supplier (one of the small companies entering the market) whose daytime rates on E7 are actually lower than I'm currently paying Eon on an all-day tariff. I'm just about to make the switch to them.

On solar panels, btw, a big thank you to the Forum users that raised the discussion on devices to route the 'surplus' solar energy. Tho' those seem not to be suitable for EV use, I was prompted by the discussion to fit one to the hot water tank in the house. I had thought immersion heaters could just be on or off, but this seems to dump sometimes very small amounts of surplus power into the tank (sometimes just 20 or 30 watts) yet the cumulative effect over the day is that we end up with a hot tank at no cost. Since I installed the device, it looks like we've dumped more than 150Kw into our hot water tank that would otherwise have had to have been heated by our gas boiler.

 

[tarq]

Yes Poins, we have a 'solarcache' on our immersion and just worked it out to the end of August, it will pay back in about 8months, had it fitted for 18 so far.

Another trick I use is when the tank's up to temp and we're PV charging over 2.5kw. I plug the PHEV in on it's 10a brick, it only draws 2,300 watts so the rest of the house will also run for free!

3 times last week I topped up to full doing this.

 

[user 417]

Wouldn't it be good if you could programme the PHEV to take less power and charge slower in some circumstances? That way you could prolong the battery life by being gentler on them if you know that you have plenty time before you need the car again.

 

[Hypermiler]

Off original topic slightly, but:
I originally raised the solar charging point, I think (asking whether there was the equivalent of Immersun for cars). I don't have pv yet - am trying to find a company to sort out whether we can have 10 kwp on our barns but is taking a while. When we do get it sorted I will get a 13 amp socket put in next to my charge point so that when I have time I can choose my charge speed, cost and eco-friendliness all from the same parking spot. How cool will that be. Just need some hippy stickers - "running on sunshine!" or something like that to adorn the car with!

Actually, if we do get 10 kw (which I doubt we'll manage grid-wise) I probably won't need to trickle charge except in winter...

H

 

[jdsx]

fwiw, this link might be useful. It appears to offer a cable which has variable current from 16A down to 6A. Clearly the 'plug' end is not suitable for UK but otherwise it looks interesting, if a tad expensive.....
http://www.e-station-store.com/en/portable-charging-stations/8-evr1-type-1-max-37-kw.html

 

[CJ1045]

I worked the numbers comparing standard fixed tarif versus economy 7 fixed tarif. I took our pre PHEV electricity consumption and assumed that was all day time tarif if we switched to economy 7 and added on the PHEV charging consumption assuming all on night time tarif on economy 7. The bottom line was that IF we charge the PHEV EVERY night 7 days a week from 20% to full every night then we would save £5 a month on economy 7. If you only charged the PHEV every other night (say to allow for non-use and/or not requiring a full charge etc) then a regular non-economy 7 tarif was cheaper but £10. We decided to stick with a straight fixed tarif as then we could charge the PHEV whenever we wanted and the cost would be the same.

CJ

 

[Peter]

I have also looked into this before taking delivery of my GX4 on Monday of this week, I have not bothered before to shop around just accepted the rate of the supplier I have been with since before privatisation but with the new car and increased consumption I thought it would be worth looking into.
I have always thought it would be best to charge over night on the eco7 tariff and checked with EDF my supplier if they could change me from the standard tariff to Economy 7, some 18months ago as my meter was due to be changed they asked if I would like a smart meter fitted which I was quite happy with (I would say the advantage of these is for the supplier not the consumer as they have instant knowledge of your consumption without the need of meter readers), sorry I digress.
the only problem with changing is that the day rate went from 15.96p per unit to 17.47p per unit and a night rate of 6.62p, this prompted me to shop around and I found M&S energy at 15.67p day rate & 6.66p night rate, better day rate than I had before and better than half price at night.
EDF has moved me onto the Eco 7 tariff and I am just in the process of changing suppliers.
I know we are all different in the way we use our cars, I am retired and my normal pattern is out in the morning back early afternoon then possibly out again in the evening and I was looking too set the charger to charge overnight then over ride it to top up before going out again in the evening.
I must admit I haven't found it that easy as I can't find a simple over ride switch, so what I have done is set the timer from 1am to 6pm so that it will I hope accept a charge during those times and plugging it and turning on after 6 it should again I hope wait until 1 before it starts charging at the cheap rate.
So yes I think I think overnight charging is cheaper but as with all things with the car it's a big learning curve!
Peter

 

[CJ1045]

Our eletricity charges are no where near as extreme as yours (OVO energy for Southern Electric Region) which mean that unless you use Economy 7 for your main heating it is not worth switching.

Economy 7 Fixed
Night 13.08p/kWh
Day 7.42p/kWh

Regular Fixed
11.78p/kWh

CJ

 

[Ozukus]

In this modern era with gas fired central heating and A/A+ rated appliances I don't see the real benefit of running Economy 7. My mother-in-law has it as she has storage heaters and every device in the house like washing machines, tumble dryers and dishwashers are all used with in built or external timers.

If I work on the basis of a 13p/7.5p rate for Economy 7 and a fixed rate of 11.8p for standard tarrif, and switch my phone/device charging, washing machine, tumble dryer, balance of the fridge freezer and allowance for device standby then it works out my average consumption of about £1.88 per day jumps to £2.11 as most of my electric usage is from devices or appliances that don't benefit from off peak pricing.

Therefore to switch the cost to charge the car overnight would have to be 23p or more cheaper to make it worthwhile plus add some on top for any daytime charging I would want to do and also allow for the inconvenience of having to manage things like washing/tumble and phone/device charger use.

I think i'll just stick to a standard tarrif and just plug it in whenever I want.

Supposed to get my delivery date today, patience is starting to run thin!!

 

[greendwarf]

Our eletricity charges are no where near as extreme as yours (OVO energy for Southern Electric Region) which mean that unless you use Economy 7 for your main heating it is not worth switching.

Economy 7 Fixed
Night 13.08p/kWh
Day 7.42p/kWh

Regular Fixed
11.78p/kWh

CJ

Seems VERY extreme to me - Night more expensive that Day? :lol: