Comparing Bulb's Three Tariffs from an EV driver

I’ve been with Bulb for about a year and a halfish, and do 40 - 80 miles a day commuting to work in a Nissan Leaf. Bulb’s new smart tariff interested me so I figured I’d try and figure out what if any difference it made. It’s important to note I’m already on Economy 7, so I have already shifted the majority of load into the night.

Breaking my usage down into Bulb’s smart tariff times:
Off-peak (Light Blue / Cyan ): 7am - 4pm & 7pm to 11pm
Overnight (Pale Blue): 11pm - 7am
Peak (Dark Blue) : 4pm 7pm

Due to unexpected lift events I didn’t do much driving between mid August and early September, and then the battery died in the energy monitor. But from what I’ve measured so far the total usage on that graph is 2.6 MWh (2631.6 kWh)! Broken down as follows:

  • Off-peak: 648.6 kWh
  • Night: 1841 kWh
  • Peak: 142 kWh

I’m going to use July to represent a typical months usage because it’s the most complete months data I have, with no life events causing deviation.

  • Total kWh: 808.1
  • Off-peak: 198.7 kWh
  • Night: 569.9 kWh
  • Peak: 39.5 kWh

Costs per tariff (current rates for new members, East Midlands pricing)
Cost on Bulb’s standard tariff:

  • 13.262p / kWh: £107.17
  • 24.56p / day standing charge: £7.61
  • Total: £114.78

Cost on Bulb’s Economy 7 tariff:

  • 15.383p / kWh in day: £36.64
  • 8.201p / kWh at night: £46.74
  • 24.56p / day standing charge: £7.61
  • Total: £90.99

Cost on Bulb’s smart tariff:

  • 12.18p / kWh off-peak: £24.20
  • 30.78p / kWh peak: £12.16
  • 8.20p / kWh Overnight: £46.73
  • 24.56p / day standing charge: 7.61
  • Total: £90.70

EV drivers aren’t really getting a lot out of the new tariff over the Economy 7 tariff unfortunately, the night rates are exactly the same but you do get an extra hour. The extra hour might be useful to some with larger battery EVs, or those with slower charging but it wouldn’t be useful to me. You however do get significantly cheaper rates throughout most of the day, if you can avoid heavy usage between 4pm - 7pm. By changing my behaviour I might of been able to save slightly more by shifting away from the peak times, but it probably wouldn’t be a lot.

I’ve signed up to the smart tariff and will be running away shortly with my £3.48 I’ll save over the year.

@MorgenBlue Jenna here from Bulb Labs. Thanks so much for including and sharing this analysis - it’s really useful for other members to get this sort of breakdown from people with access to data like yours :slight_smile:

Your maths looks good to me, without going into the weeds too much. You are right that compared to Economy 7, our new Smart Tariff doesn’t represent vast savings. But it does encourage people to avoid peak usage which is good for the planet. It’s also a lot ‘smarter’ - you’ll be able to keep an eye on costs better and you’ll have fixed times. One of the problems we know our EV driving members have with Eco 7 is you’re never quite sure when it will kick in!

When we were thinking about pricing our Smart Tariff we had our EV drivers on our one-rate tariff more in our minds. We think only around 20% of our EV drivers have Eco 7. Current one rate tariff EV drivers can save up to 30% by switching to Smart.

If you haven’t already, please sign up to Labs as we are working closely with our EV drivers at the moment to design the future of Bulb and perhaps we can meet or chat to learn more about your views. Thanks!

Yeah, it’s a bit awkward figuring out when exactly economy 7 starts on traditional meters. Some meters follow daylight savings, some don’t and even if you know what time the meter is supposed to switch over, the clocks on them are more often than not wrong so you have to figure out the offset yourself.

For most people I think it’s probably a better option than Economy 7, even if it isn’t significantly saving you money. It will encourage better behaviour to help reduce emissions from the grid.