MSE Guide - Electric vehicle energy tariffs

Reed_Richards

I have the NextDrive tariff with Eon Next.  AFAIK there are no restrictions on what charger you use with this tariff.  I don't even have a fancy home charger, just a "granny charger" that plugs in to a standard socket.  

TheBanker

SussexSid said:

I have a plug-in hybrid. I have a home EV charging point that we installed when we had solar panels fitted. 
So far I have looked at Ovo (my current electricity provider), Octopus and E-On and they all only support certain home chargers. Bottom line, not all home chargers are equal. 

Intellegent Octopus Go only supports certain chargers OR certain cars. This tariff allows Octopus to control when your car is charged (you tell it how much charge you want, and when you need it by, and they schedule it based on when there's surplus energy). It's a good tariff because you're charged 7.5p per unit for all electricity between 11:30pm and 5:30am, including anything you use in your house. You're also charged 7.5p per unit outside these hours if Octopus decide to schedule your car to charge then.

To enable Octopus to schedule your charging either your charger or car has to be compaitible. 

If you do not have a compaitible car or charger, you could consider Octopus Go (the non-intellegent version) which charges 9.5p per unit between 00:30 - 04:30 so you can manually schedule your car to charge for four hours at a cheap rate each night.

Or, depending on your usage and appetite for risk you may find Agile or Tracker more suited to your needs.

juwlz

We have 2 EVs including one that we've had for over 18 months, but between them, their mileage is relatively low - approx 400-500 miles per week (20,000-25,000 miles per year) in total.  

TL;DR version:  if your car charging (and other load shifted electricity use - for those EV tariffs that include that too) doesn't make up more than 50% of your total household electricity use, there are cheaper options available.

We are with Octopus, and (now) have a Smart charger (and have had a Smart meter for many years).  

I automatically assumed that we would switch to an EV tariff once we had our charger, but a delay in the installation made me consider other options while we were waiting.  

We switched to Octopus Tracker (from Flexible) on 1st Jan, having compared 2 years of historical pricing.  This reduced our bills by 35-40% at a stroke (for both gas and electricity), saving us approx £75 per month. (We also had to change our monthly Direct Debits to reflect this dramatic drop in our bills.)

Octopus Tracker is a wholesale price tracking tariff, similar to Agile Octopus, but simpler - prices change just once a day at midnight.  

When I did the arithmetic in anticipation of our EV charger installation finally being completed, I realised that the high day price on the Octopus Intelligent Go tariff (currently around 3p MORE than the current standard "Flexible" capped tariff) means that you have to do a LOT of miles (or have some other means of taking advantage of the cheap rate, such as a house battery) to make EV tariffs cheaper than the Tracker tariff we were already on - which was ALREADY saving us 35-40% compared with the standard capped tariff. 

As a rough guide, we'd have to use 50% or more of our electricity at the cheap rate for their best EV tariff to be cheaper for us.  Only 36% of ours is used for car charging.  We could maybe increase that to 40% with some determined (including some inconvenient) load shifting, but I doubt it.  

For more rules of thumb, we can add approximately 10 miles of range per hour with a granny charger, or 30 miles with the EV charger.   So a 6 hour cheap charging period could add 180 miles of range.  Only one of our cars has a battery capacity larger than that, but could still be charged from 0-100% in two nights; the other could be charged from 0-100% overnight in a single night ... so we'd only be able to use less than half of the cheap energy available on an EV tariff.  The rest wouldn't be any use to us, so we'd be stuck using the more expensive daytime energy for everything else.  

The charging rate and range figures will vary by car and other factors, but they're a reasonable rule of thumb.    One of our cars (a Kia e-Niro) gets 4.5 miles/kWh (the EV equivalent of mpg).  The other (a VW e-Up!) gets about 6 miles/kWh, mostly driven in Eco+ mode.  

Once our charger installation was completed, I wanted to compare Tracker against Agile (where the prices change every 30 minutes).  The plunge (negative) pricing slots that started to be made available on 10th April gave me the incentive I needed to compare the last 3 years' average daily price on Agile with the daily price on Tracker - knowing that we could do better than that by load shifting as well.  I also used the Octopus Compare app which takes your own actual usage history and tells you what you would have paid on a different tariff.  

Until November 2023, Tracker had been cheaper than the average daily price for Agile.  From December 2023 to April 2024, Agile was cheaper (without any load shifting to take advantage of the cheapest times of day).  I'd also compared Tracker with the "Flexible" (standard capped) tariff prices for the whole of 2022 and 2023 before we switched to Tracker.  Even after the Russian invasion of Ukraine in Feb 2022, there were only 2 days out of 730 when Tracker prices were (slightly) higher than the standard rate.  Mostly they were SO MUCH cheaper that the start of the energy crisis only served to bring them closer to the standard rate until the standard rate also had to increase and the energy caps were brought into play.  

We switched from Tracker to Agile on 11th April, and spent that weekend with a price limit of 0p set on our charger (which integrates with the Octopus EV and Agile Tariffs to choose the cheapest charging slots) and let it schedule times to charge both cars when we were being paid most to do it.  Plunge pricing is the exception rather than the rule - we happened to have a lot of the right sort of wind for a few days to generate a lot of green energy, and we were doing our bit to help balance the grid and use up excess generation more cheaply for the energy generators than switching off a wind turbine somewhere.  You shouldn't expect it if you switch to Agile, but it's a nice bonus when you get it.  

Even without the plunge pricing, Agile is working out even cheaper for us than Tracker, and the integration between our EV charger and the Tariff to pick the cheapest times to charge works really well.  We just tell it how much we want, and when we'd like to leave, and let it get on with it.  

I use the Octopus Watch app to analyse our usage.  Just in the last week, since we switched from Tracker to Agile, we've changed our use pattern considerably (and easily) to avoid unnecessary use between 4pm & 7pm, and use the car charger to pick the cheapest times to charge.  It's gratifying to look at the graphs of pricing vs consumption and see their peaks and troughs at opposite times of day.  

If we didn't have a charger that integrates with Octopus Agile, the 3rd party Octopus Watch app has good tools for finding the best time for in the day for tasks of various lengths if we had to do it manually.   

So in summary, EV tariffs are not the universal panacea for cheap EV charging that the adverts would have you believe.  

They CAN work well for people with a long commute who don't get free or subsidised charging at work, but for many people with just a local commute or school run with occasional longer trips, they can be an expensive poor choice.

juwlz

wakeupalarm said:

Can someone explain how these energy suppliers can offer EV tariffs for 5p?  They must all be loss leaders as the cost of the energy produced is the same as any other energy.

What will happen when there are millions of EV on the roads, and millions of Heat Pumps installed in homes.  Surely, the price will just increase to be the same as anything else that uses electricity.

Unless they are being subsidised by EV manufactures, what's in it for the Energy suppliers.  A unit of electricity sold at 21p is surely better for the Energy supplier then a unit of electricity sold at 5p?

They do it by making the daytime / non charging rate higher than the standard capped rate.

EV tariffs are only suitable for people who drive enough miles each week for enough of their total electricity usage to be at the cheap rate to offset the higher rate the rest of the time.  

We have 2 EVs, drive 400-500 miles per week (20,000-25,000 miles per year) between them.  

We don't have solar panels or house batteries. 

We charge entirely at home (except for occasional long trips when we have to use public chargers), but that only makes up 36% of our total electricity use. 

It needs to be about 50% to make IOG cheaper than Tracker, because of the high daytime price for up to 18 hours (when not using cheap daytime charging slots) on IOG.  

We were on Octopus Tracker (which saved us around 40% compared with the varied Flexible rate) until we had our EV charger installed. Now we have an Ohme Home Pro charger which has excellent integration with Agile Octopus to pick the cheapest slots to get to our required charge, and has helped to reduce our bills even further. We still cook between 4pm & 7pm, but the rest of our usage (laundry, dishwasher, etc.) is load shifted to cheaper times of day (usually overnight, or the other cheap periods between lunchtime and 4pm).