Comparison Update for November: Octopus Intelligent offering peak energy at 30.5p and OVO at 30.22p (regional variations will exist) there is currently no significant difference between the two on daytime energy in your home. Octopus night rates are at 7.5p per kWh against OVO’s flat charging rate of 7p per kWh. OVO is likely to be your best bet if you often charge during the day and can’t shift much energy use off-peak (like immersion heaters etc), otherwise it looks like Octopus Intelligent will bring more households greater savings.
Background: Last year, Octopus Energy launched Intelligent Octopus, a tariff with a minimum six-hour off-peak window. You pay 7.5p/kWh for off-peak electricity in exchange for handing over the micro-management of your overnight charging. This is lower than the 9.5p/kWh off-peak on the basic ‘time-of-use’ Octopus Go EV tariff. Plus, if Octopus starts your charging outside of the off-peak hours, you’ll get some bonus cheap home energy.
Meanwhile, OVO’s electric car tariff, Charge Anytime, is a ‘type-of-use’ tariff just for your EV, with a charging rate of 10p/kWh. You’ll get this rate no matter when your car charges if you use their scheduling app and allow them to manage charging around your life.
OVO Energy’s EV tariff Charge Anytime works with any of their available tariffs, even the basic SVT (the default Standard Variable Tariff). The downside of OVO’s new electric car only tariff is that you’ll only get your EV charging at the cheaper rate. All your home electricity use is charged at your standard unit price.
How much could you save?
Why are EV tariffs changing?
The basic idea behind an EV tariff is to reward you with cheaper energy when there’s energy to spare. Typically this is at night. Overnight hours have lower demand, which also generally makes them greener because there’s less need to switch on more expensive, carbon-intensive gas power generation.
However, the fixed off-peak window you are given with an EV tariff doesn’t always coincide with the cheapest and greenest energy. The supply of green energy from solar or wind energy can peak at any time of the day or night. More to the point, as the EV tariff Octopus Go got popular it started to create its own mini-peak, as thousands of EVs started charging at exactly the same time every night.
Smarter managed charging tariffs make your EV’s energy use even greener
Supply and demand need to be properly matched. One way is to give energy users a price that varies with each 30 minutes of the day and night (like the Octopus Agile tariff does). Another option is for energy companies to offer cheaper prices in exchange for handing over control of the demand – allowing them to turn charging on or off, up or down depending on what’s happening on the grid. All the while ensuring your car is ready when you need it.
Octopus Intelligent vs. OVO Charge Anytime
The topline is the same for both: you charge cheaper when you sign up for managed charging. Both Octopus and OVO do this by connecting either to a compatible charger or by talking straight to your (compatible) EV.
For both suppliers, you use an app to set your schedule. This can be either the time you need your car to be ready or the miles you’d like to add. Like magic, your car will be charged when it’s greenest for the grid.
What if I forget to schedule my EV charge?
If you need to switch on your charging at an unscheduled time, sometimes called a ‘boost’, you’ll be charged at the higher rate by both tariffs. Charging at Octopus’ daytime rate currently costs around 6p more per kWh than OVO’s lowest tariff, the exact prices depend on where you live.
If your work patterns mean your car isn’t around for some of Intelligent’s 11:30pm-5:30am off-peak, you’ll miss out too, whereas OVO’s 10p/kWh applies to any ‘ready-by’ time.
Is Octopus or OVO cheaper for my home energy use?
On Octopus Intelligent, all your home’s energy use in the 6 hour off-peak window is at the cheaper rate. That means it can be around 7.5p for an overnight dishwasher cycle. But, if you can’t shift or forget to delay your appliances, you’ll pay around 40p for the same dishwasher load.
With OVO, you can be on the standard tariff for your home use – so your dishwasher load currently costs around 34p no matter when you start it.
How much can Intelligent save me if I shift?
As your car will generally be charged at the same cost, the difference in your savings could all boil down to your home electricity use – how much you use overall and how much you can shift around.
Most of us have a daily schedule that is hard to shift – this includes washing machines, fridges and freezers, ovens and electric showers.
| ‘Difficult to shift’ electricity use | kWh/
per year |
OVO
(@30.22p/ kWh) |
Octopus Intelligent
(@30.5p/ kWh) |
| Total ‘difficult to shift’ use | 2,932 | £997 | £1,173 |
For this ‘difficult to shift’ energy use, getting the lowest OVO tariff saves £8 per year vs. Octopus Intelligent.
The best tariff may all come down to how much energy use can you shift
What about the energy use I can shift?
Despite the many things we can’t move overnight, there are lots of ways that households on EV tariffs can make use of their off-peak rates.
However, if you have more to shift – say a busy dishwasher and an energy-hungry immersion heater, the savings from Octopus Intelligent start stacking up. As you can see below:
| Shiftable electricity use | kWh
/year |
OVO
(@30.22p/ kWh) |
Octopus Intelligent
(@7.5p/ kWh) |
| Dishwasher (7 cycles per week) | 438 | £132 | £33 |
| 3kW immersion heater (an hour per day) | 1095 | £330 | £82 |
| Total ‘shiftable’ use | 1533 | £462 | £115 |
With the above hefty energy load shifted, Octopus Intelligent is now much cheaper for shiftable use. This makes it much cheaper than OVO overall. Plus, with the extra hours of off-peak that Octopus may schedule for you, you can expect extra savings. Octopus have told us that they move around 20% of smart charging outside of the normal off-peak window – giving you an extra 20% of off-peak hours for your home.
The further you go along the ‘electrification of everything’ route, with heat pumps and home storage, the more sense a tariff like Intelligent makes for you.
How can I sign up to a managed EV tariff?
To be eligible for Intelligent or Charge Anytime, you must have a smart meter and either a compatible charger or a compatible car. If your car can communicate directly with your energy company through an API (like Tesla does) it does seem to make scheduling easier.
| Octopus Intelligent | OVO Charge Anytime EV tariff | |
| Chargers | Any Ohme charger | Indra Smart Pro Indra Smart Charger v3 Ohme Home Ohme Home Pro |
| Car Makes | Audi, BMW, Ford, Jaguar, Land Rover, Skoda, Tesla, VW (excluding ID models) | Audi, BMW, Cupra, Ford, Jaguar, Mini, Porsche, Renault, Seat, Skoda, Tesla, Volvo, VW (including 3.0+ ID models) (check latest models here) |
Compatible cars and chargers are getting added to both tariffs all the time, so check out the suppliers’ websites to see the latest requirements.
You’ll also need to download an app to schedule your charging.
What if I have solar?
If you have solar on your roof, you won’t be able to move to OVO’s Anytime tariff unless you have an Indra Smart Pro Charger. This is because Charge Anytime can only tell how much electricity you’ve used, not where it’s come from. If your home has solar panels it’s harder to work out how much has actually come from the grid.
You can switch to Octopus Intelligent if you have solar, but all the clever stuff you do through a solar-integrated charger (like a Zappi) won’t work yet, although Indra are hoping to get on the compatible list soon.
How much can an EV tariff reduce my car’s carbon footprint?
In the UK our grid energy has an average carbon cost of 200g. For your electric car, this means 50g of carbon is produced somewhere else for every mile you drive on average grid energy. This compares to 272g for the average petrol car in the UK. As more renewables are built, the grid is getting cleaner. The target for 2030 is an average 100g per kWh.
But there’s more to the story than the average. In reality, most EVs are charging when the grid is greener than average. The lowest grid carbon registered in 2020 was 42g (so around 10g of carbon per mile).
In our own calculations, shifting from peak charging (coming home at 5pm and plugging in during the evening peak) to off-peak (automatically setting your charging from midnight onwards) lowers carbon intensity by 26%.*
With managed charging, the results would be even more dramatic, as you could only need to charge up over the best five or six hours (carbon-intensity speaking) per week.
How can electric cars support green energy?
The challenge for green power is that our routines are surprisingly similar – we get up, travel and cook at the same time. We create predictable but stubborn peaks and troughs in demand. And renewable power doesn’t just turn up at the right moments to supply these routine demands.
The carbon cost depends upon when you charge your EV
But EVs can help shake things up. Charging is a relatively move-able demand, as your car is often stationary for many hours at a time, especially overnight. In the future our cars will also be used as batteries for our homes, or even the grid, reducing the peak.
Demand that meets the supply of energy means more renewable power can be used directly. Excess renewable energy is often diverted into storage and used later, but around 25% gets wasted this way. Sometimes spare energy is even dumped as it can’t be cost-effectively transmitted or stored.
EV tariffs are not just money-saving for the EV driver who switches – the better we get at using electricity when demand is otherwise low, the more efficient and low-cost our grid can become for everyone.
*We calculated the carbon saving using data on carbon intensity from National Grid ESO for August 2019 – August 2020.