Smart Tariff with Economy 4? — Bulb Community

Smart Tariff with Economy 4?

[Rewriting this because the forum ate my thread]

Several suppliers are now starting to offer Economy 4 tariffs, and it's something I'd like to see Bulb offer. It's much like Economy 7, but as the name implies it has four hours overnight that are cheaper instead of the traditional seven hours and it looks like the tariffs from other suppliers are generally about a third cheaper than the economy 7 night rates.

Bulb's current smart tariff doesn't really offer anything to EV drivers, and limited benefits to battery storage users (as I posted in my analysis in November https://community.bulb.co.uk/discussion/7398/comparing-bulbs-three-tariffs-from-an-ev-driver#latest ). It's essentially Economy 7 with a cheaper day rate throughout most of the day. While I support the idea of trying to move people away from peak times, as it will help to reduce reliance on coal and gas plants I don't think it offers much of a financial benefit over traditional economy 7.

As an EV driver, PV owner, and soon to be battery storage owner, it would work out much better to have four cheaper hours. I don't really need seven hours as I can pull from the grid at 12 kW (so a max of 48 kWh at four hours), but only have to pull 42 kWh each night.

Perhaps @Jenna at Bulb may be able to weigh in on any research being done around Economy 4 style tariffs?

Comments

  • Hi @MorgenBlue... we saw your analysis of the 3 tariffs which was great :3 You're right that 3 rate (Smart) doesn't offer much over economy 7 for EV drivers - but our analysis showed that only 25% of EV drivers have Eco 7 meters and so for that 75% it does offer a significant saving over our Vari-fair tariff. We were having EV driving members call us to request their meters be switched to Economy 7 meters - which we not only, have to charge for, but seems utterly daft when they could have a Smart meter, which will be a gateway for much more functionality in time.

    With regards an even cheaper overnight rate - for a shorter period - it is something we are looking at in Bulb Labs, along with other offers for EV drivers and battery owners. Believe me, we spend all day talking about what we can do to offer more for you! Our thinking at the moment is that it is hard to decide which 4 hours to use to set this lowest cost - the wholesale cost is not always consistent. We are also keen to build the renewable aspect into the way we do things - with the predictions of the numbers of EV's coming - we want to make sure they are being charged on lovely wind or hydro power and not causing more coal-fired stations to be switched on midnight to 4am! No one wants that. We think the answer is probably smart chargers working with smart meters (where your charger is remotely switched on and off according to cost/grid circumstances) We are putting our efforts into that technology. More to be announced soon. Watch our blog for more.

    Look forward to your thoughts :-)
  • With regard to overnight charging for EV owners, it would be interesting to know the numbers in terms of how many require 7 hours charging compared to how many can cope with less. At the moment I would imagine most are restricted to drawing 6.6kW because of the capacity of their car's onboard charger. Plenty Nissan Leaf owners of pre-2018 vehicles will only be able to draw 3.3kW. Then of course it comes down to battery size and how much charge is actually needed for the following day.

    A 24kWh Nissan Leaf owner requiring a full charge from a 7kW home charge point would need those 7 hours offered by Economy 7. But plenty might not require a full charge every day. A 30kWh Leaf could fully charge from empty in under 5 hours if it had the 6.6kW onboard charger (my situation) but of course many drivers won't need a full charge and won't be topping up from empty (again my situation), so I could likely cope with Economy 4. Another 30kWh Leaf owner with a 3.3kW onboard charger would however need 7 hours to charge from 20% to 100%. Again might not need a full charge, and so on and so forth. Plenty permutations.

    As @Jenna at Bulb said, smart meters in tandem with smart chargers are probably the way ahead with regard to E4 types of tariff. The Zappi home charge point (from myenergi) looks to be excellent, especially for those with solar panels (not me). However they're not cheap and I think the vast majority of EV owners at present probably have dumb chargers installed (myself included), so I'll be interested to see what ideas Bulb come up with for drivers of electric vehicles.
  • edited February 13

    With regard to overnight charging for EV owners, it would be interesting to know the numbers in terms of how many require 7 hours charging compared to how many can cope with less. At the moment I would imagine most are restricted to drawing 6.6kW because of the capacity of their car's onboard charger. Plenty Nissan Leaf owners of pre-2018 vehicles will only be able to draw 3.3kW. Then of course it comes down to battery size and how much charge is actually needed for the following day.

    A 24kWh Nissan Leaf owner requiring a full charge from a 7kW home charge point would need those 7 hours offered by Economy 7. But plenty might not require a full charge every day. A 30kWh Leaf could fully charge from empty in under 5 hours if it had the 6.6kW onboard charger (my situation) but of course many drivers won't need a full charge and won't be topping up from empty (again my situation), so I could likely cope with Economy 4. Another 30kWh Leaf owner with a 3.3kW onboard charger would however need 7 hours to charge from 20% to 100%. Again might not need a full charge, and so on and so forth. Plenty permutations.

    As @Jenna at Bulb said, smart meters in tandem with smart chargers are probably the way ahead with regard to E4 types of tariff. The Zappi home charge point (from myenergi) looks to be excellent, especially for those with solar panels (not me). However they're not cheap and I think the vast majority of EV owners at present probably have dumb chargers installed (myself included), so I'll be interested to see what ideas Bulb come up with for drivers of electric vehicles.

    I have a Zappi, and it wasn't expensive. Only cost me £550, which is about the same as everything else. EVs with lower powered chargers might benefit from the longer charge times, but these are quickly becoming a thing of the past. Kona and pretty much every other EV on sale has a 7kW+ charger, Zoe is 22 kW+ (if you are lucky enough to have three phase power), and 40 kWh Leaf onwards has 6.6kW standard. I've got a 2017 30 kWh Leaf with a 6.6kW charger. With the advent of relatively affordable EVs capable of 200 or even 300 miles coming to market this year, I think we are going to see a huge influx that will dwarf the current EV fleet by the end of next year.

    Hi @MorgenBlue... we saw your analysis of the 3 tariffs which was great :3 You're right that 3 rate (Smart) doesn't offer much over economy 7 for EV drivers - but our analysis showed that only 25% of EV drivers have Eco 7 meters and so for that 75% it does offer a significant saving over our Vari-fair tariff. We were having EV driving members call us to request their meters be switched to Economy 7 meters - which we not only, have to charge for, but seems utterly daft when they could have a Smart meter, which will be a gateway for much more functionality in time.

    With regards an even cheaper overnight rate - for a shorter period - it is something we are looking at in Bulb Labs, along with other offers for EV drivers and battery owners. Believe me, we spend all day talking about what we can do to offer more for you! Our thinking at the moment is that it is hard to decide which 4 hours to use to set this lowest cost - the wholesale cost is not always consistent. We are also keen to build the renewable aspect into the way we do things - with the predictions of the numbers of EV's coming - we want to make sure they are being charged on lovely wind or hydro power and not causing more coal-fired stations to be switched on midnight to 4am! No one wants that. We think the answer is probably smart chargers working with smart meters (where your charger is remotely switched on and off according to cost/grid circumstances) We are putting our efforts into that technology. More to be announced soon. Watch our blog for more.

    Look forward to your thoughts :-)

    Not opposed to having the hours be variable, the key is making it so that data is easily accessible both via an API and for humans to program non-smart devices (e.g. dishwasher). I should be getting my hub for the Zappi next week and I'm hoping it will have some sort of APIs. If it does I will probably spend a bit of time writing a program to integrate the charging times with the Carbon Intensity API, and do the same for my Powerwall whenever Tesla get around to shipping it.

    It will no doubt be a challenge for many to implement the variable times though at first, as even though a lot of chargers claim to be smart I don't really know of any outside of the Zappi with the capability to vary based on user input. However Bulb and other suppliers pushing these types of things may well drive the charging manufacturers to implement something for it more quickly. Considering the difficulty of dealing with things being variable, to get wide take up it would have to have other benefits over competitors fixed time Economy 4 tariffs.
  • I think the biggest shift to variable rate tariffs may be when more companies start to produce CADs and suppliers (or other DCC users) make it easier to connect them to the communications hubs.

    A CAD that has a load of relays/low current outputs would make it very easy to trigger contactors for storage heating/dumb chargers, or input triggers on slightly more smart devices.

    We may find that in a year or two, smart chargers are coming SE1.4 certified (for SMETS2) ready to connect directly to your Smart Meter's HAN.
  • That would certainly help, but I think we could see a large take up from EV owners very quickly if charging companies and energy companies manage to work together to create something both easy to integrate with, and with a significant financial incentive.
  • edited February 14
    I had analysed my own usage pattern on E7 with two electric cars, solar panels which is about 80% night rate usage and tried to interpolate this onto the bulb smart tariff and found that it would likely be more expensive for our case due to the evening peak rate versus standard E7 unless a small battery storage system was also installed.

    I find this topic about a potential 4 rate tarrif with perhaps 3 or 4 hours overnight at an even lower rate most interesting as this might make it more palatable even before any battery storage added (depending on what the other rates are)

    I have a new style untethered Zappi on pre-order to swap out my primary wall charger to increase our self-consumption further of generated solar during the daytime which would also reduce our current daytime import usage which my current crude setup causes as the granny charger uses a fixed 2.4Kw in 15 minute blocks when there is a surplus above 1.2Kw available (only once the hot water / central heating tank is hot)

    My usual 60 mile usage on my 30Kwh Leaf is about 70-80% in winter on my main commuting days Monday to Wednesday (working from home Thursday and Friday) this takes around 3 to 4 hours at the peak 6.6Kw before it tapers off.

    Currently I have the leaf set to start charging at 03:20 on Mondays to Wednesday ready for a departure at 06:30. I tweak this by 10 minutes or so occasionally as deepest winter approaches such that I am always charged to above 90% for departure. (I find leaving the charging to later rather than start at beginning of the E7 tariff at 0:30 in winter to be beneficial to get the battery warmer).

    On Thursdays and Fridays due to WFH I am unlikely to be using the leaf so I charge later for 2 hours such that I have 50-60% should I need it, then swap to the solar setup to add extra charge should the sun be shining greatly (Feb to October). The Zappi will improve this efficiency as it has an Eco+ mode where it will pause charging quicker and has a far lower trickle charge (6 amp or 1.4Kw) and is instantly variable to match the spare solar as opposed to the the granny charger which is fixed for 15 minute intervals (10 amp or 2.4Kw).

    If I upgraded my Leaf to the 40Kwh or forthcoming 64Kwh in a few years although the battery is larger my actual charging time on Monday-Wednesday would not increase as I am travelling no further. However the surplus battery available would perhaps allow to charge for say only 3 hours max on these nights but start off with a fully charged battery on the Monday to be recouped over the other days when my usage is generally lower.

    My wife currently has a 10Kwh vauxhall Ampera hybrid range extender. We use the granny charger 2.4Kw on this starting at 01:45 which if empty completes around 07:15.

    The plan once the Zappi is installed is for this to also be plugged into the Zappi when it gets home during the day on Eco mode (no pause but at minimal trickle until the solar increases) or if empty to select a 2 hour boost at the max setting (of 3.3kw limit of the Ampera) should there be a further journey to be made.

    The zappi can also be set to use the surplus before the hot water tank or future battery storage is full.

    My wife is out all day on Thursday and Fridays whilst I work from home so I leave my Leaf set for the solar surplus (on eco+ charging once the Zappi is fitted)

    For the weekend I have the leaf set to charge fully overnight ready for any long journey usage whilst the Ampera is only used for the first journey in the day after which it can be plugged into the Zappi on eco+ mode only to charge if sunny.

    The Zappi can be set to sense the presence of an E7 or low tariff presence via the switched E7 circuit or via an additional hub it could feasibly interact with the smart charger itself.

    Currently for the leaf the inbuilt timer is used, but if the extra low rate is variable timing rather than fixed then I would imagine the Zappi could sort that out rather than the leaf timer to auto set the ideal charging time period.
  • I'd be nervous about limiting charging to such a small number of hours. The wire running down your street is potentially limited to 1-2kW per house (it's surprising the extent to which everyone draws power at different times making that ok). If the network had to support everyones EV being charged at the same time in the same 4 hour slot there would be a need for far more cables. The cost for that would ultimately would end up back in everyones bills.

    The Electricity networks have actually been looking at how to control EV charging to limit the impact on networks for some time. There is a good summary of one project here, along with interesting data on how much people tend to charge electric vehicles by.
  • ThatGuy said:

    I'd be nervous about limiting charging to such a small number of hours. The wire running down your street is potentially limited to 1-2kW per house (it's surprising the extent to which everyone draws power at different times making that ok). If the network had to support everyones EV being charged at the same time in the same 4 hour slot there would be a need for far more cables. The cost for that would ultimately would end up back in everyones bills.

    The Electricity networks have actually been looking at how to control EV charging to limit the impact on networks for some time. There is a good summary of one project here, along with interesting data on how much people tend to charge electric vehicles by.

    Ultimately the shorter times vs Economy 7 doesn't have much of an impact with how things are now. Most people using Economy 7 (or a variable time tariff) will simply have everything set to come on at the start of that timer, most likely at full power. So after 4 or so hours everything is settling down anyway.

    What National Grid want to avoid (and shown in that document) is people charging at peak times. Generally people get home and plug in straight away (I do), but if you don't have cheaper off-peak rates then you have little incentive to delay charging. Obviously everyone coming home from work between 5pm and 7pm and immediately adding an extra 7kW load is bad, demand is significantly lower at night.
  • edited February 15
    I could forsee a tariff which gives you 4 or 5 hours of much cheaper electricity, at some point between 22:00 and 07:00 based on what your supplier deems will balance the grid best/will be cheapest.

    That would solve the problem Jenna mentioned above:
    Our thinking at the moment is that it is hard to decide which 4 hours to use to set this lowest cost - the wholesale cost is not always consistent.
  • Hey All - great discussion - I've been sharing all your thoughts with the Labs team here. Just an update on the smart charging idea I alluded to....

    Bulb recently announced that we are planning a trial with a new generation of electric vehicle (EV) smart chargers in 2020.  Smart chargers help you to pay the least amount of money when the grid is the cheapest by remotely controlling your charger - essentially it switches charging on and off in relation to grid conditions (wholesale costs and renewables mix, for example), whilst still ensuring your car has the required charge by the time you need it. We hope this will mean EV drivers can charge their car even more cheaply (and greener) - naturally passing these savings on to you.

    We're working with smart meter company EDMI to develop and then trial the next generation of these meters with Bulb members in 2020. You can read more about it on our Blog here. If you have an electric vehicle or are thinking about getting one in the next year and want to register to take part in this trial for 100 households across the UK, you can sign up here. We’d love to hear any thoughts or questions you may have about this technology. We’re still in the early stages and would love to understand our members’ hopes, fears and expectations around it.
  • Hi @Jenna at Bulb. Will the trial involve participants on the current Bulb Smart Tariff or is the plan to trial a new tariff/(s)?
  • edited February 22

    Hi @Jenna at Bulb. Will the trial involve participants on the current Bulb Smart Tariff or is the plan to trial a new tariff/(s)?

    Given the stated aim is to save money on charging, I would assume that the tariff is going to be different. There has to be some financial incentive to allow "smart" charging rather than simply using the in-car timer to charge at any time during the night rate.

    @Jenna at Bulb I've filled out the Bulb Labs form. I'd already done it previously but this one seems to have some new questions so I've filled it out again just in case.

    I'm interested in joining the trial, but to be honest my main concern is simply how many more holes would have to be drilled in my house to mount the new EVSE in place of my existing one! I wouldn't want to be left with holes to have to try to fill/cover once the old charger is moved back again.
  • Hooloovoo said:

    Hi @Jenna at Bulb. Will the trial involve participants on the current Bulb Smart Tariff or is the plan to trial a new tariff/(s)?

    Given the stated aim is to save money on charging, I would assume that the tariff is going to be different.
    Granted. I was angling for more detail on how it would work in practice. Assuming the cost of energy varies throughout the day, do Bulb already have a certain amount of information on this and therefore specific hours they wish to test with a tariff? Or is the idea that there are no set hours at all? Or is it more the technology they want to test and the tariff is a somewhat secondary consideration?
  • It sounds interesting. Echoing the questions around the tariff, if any general ideas of what it will be can be shared. Also interested in how it will interact with solar and battery storage.
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