Notifications

Clear all

Octopus tariffs - a quick comparison

Electricity, Tariffs, Monitoring & Providers

Last Post by Tim441 35 minutes ago

4 Posts

2 Users

0 Reactions

9 Views

RSS

Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 317

Topic starter 31/08/2025 11:38 am

I've drawn up a comparison list for friends & family. Please suggest corrections/additions. I know its possible to go on and on with so many variables! So just focused on initial guide.

Octopus Energy Tariffs – Quick Guide

Flexible (Standard)

Variable rates with the Ofgem cap.
Typically the most expensive.
Most people can save with an alternative tariff.

Fixed

Rates fixed for 12 months.
Typically ~15% cheaper than Flexible.
A safe, predictable option — unless wholesale prices fall during the contract.

Tracker

Daily rate linked to wholesale prices.
Long-running tariff, typically 20–30% cheaper than Flexible.
Occasionally higher on cold/low-wind days, but capped and usually cheaper over the year.

Agile

Half-hourly wholesale-linked pricing.
Best for homes with batteries or ability to time-shift use.
Can go very low (even negative), but also spike at peak times.
With smart shifting/batteries, savings of 50%+ possible.
Rates are capped by Octopus.

Like Economy 7: very cheap overnight (4 hours), higher daytime rates.
Ideal for EVs, storage heaters, heat pumps + batteries.

Intelligent Go

Smarter version of Go with ~6 hours overnight at ~7p/kWh.
Requires a compatible EV/charger.
Great with batteries and/or time-shifting.
Potential savings up to 75% vs Flexible if optimised.

Flux

For homes with solar + batteries.
Cheap overnight import, premium export rates in the evening.
Needs manual scheduling or automation for best results.

Intelligent Flux

Same as Flux but fully automated for GivEnergy battery users.

Cosy

For heat pump households.
3 cheap periods daily to align heating.
Best with a battery.
Around 20% cheaper than Flexible.

Power Pack

For V2G (vehicle-to-grid) setups.
Lets you charge your EV for free by exporting back to the grid.
Still early-stage; requires V2G-compatible EV + charger.

Listed Grade 2 building with large modern extension.
LG Therma V 16kw ASHP
Underfloor heating + Rads
8kw pv solar
3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter
Manual changeover EPS
MG4 EV

Quote

Topic Tags

Octopus tariffs

HowardP99

(@howardp99)

Active Member Member

Joined: 2 years ago

Posts: 7

31/08/2025 12:52 pm

If you have adequate battery storage and inverter capacity then the Cosy price works out at around 50% of the standard tariff and the heat pump can be used 24 hours per day throughout the coldest months, which is a good deal better than indicated by the summary statement above. My system has 25.6kWh of storage and a 7kW inverter as well as a useful amount of solar generation. I find that even in NW England the solar actually provides surprisingly useful returns on many winter days and, on average, I can get around 15% of the running daily consumption in December and January from solar. Clearly, some days are virtually zero but the mid-winter average is about 15% of demand. The months of November and February are significantly better as they benefit from the slightly longer daylight hours and higher sun elevations. I find that I can power my heat pump using the low-rate Cosy grid supply (8 hours each day) and also charge the batteries during these periods such that there is virtually never any need to use either the intermediate or the high premium Cosy rates. Having a 7kW charge rate is critical here but you need a G99 approval. The charging of the batteries whilst simultaneously running the HP 24 hours a day works on even the coldest days. Inverter conversion losses do erode the savings but after allowance for losses I reckon that Cosy will save me about 40% over the standard tariff on the coldest of winter days. The inverter inefficiency also creates a warm area within the house so all is not lost here either.

ReplyQuote

Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 317

Topic starter 31/08/2025 1:05 pm

@howardp99 yes, would agree.

I tried to say saving might be 20% but batteries will definitely improve matters. And as you say charge/discharge rates also matter... a lot!

Your detailed info helps with a deeper dive. Similarly all tariffs may benefit from deep dive.

Hopefully the base comparison is a useful starting point.

ReplyQuote

Tim441

(@tim441)

Prominent Member Contributor

Joined: 3 years ago

Posts: 317

Topic starter 31/08/2025 1:16 pm

I'm on Intelligent Go . Only since start of Feb. Before that Agile... and before that Tracker.

Imports so far this year are under 8p/kWh and I've exported more by filling batteries at night and maximised solar exports.

High user with ashp & ev so likely imports for a full year may be 13000kWh. If I can keep near to 8p that will cost around £1000.

Exporting say 6000kWh @ 15p/kWh =£900

Perhaps a whole year heating, lighting, ev etc will cost around £100 - transforms the economics of the various bits of tech.

Tracker in 2022/23 saved me over 20% vs Flexible rates

Agile in 2023/24 saved circa 50% vs Flexible rates.

Intelligent Go in 2024/25 is on track to save 75% on imports alone vs Flexible rates. But with the extra savings by increasing exports its probably saving over 90%!! All depends how you slice & dice the calculations.

Without IOG I would probably import a lower 10000kWh on Flexible rates 26p ~ £2600.

Exports would be lower at say 3000kWh = £450

Net cost say £2150

This post was modified 3 minutes ago by Tim441