Economy 7 vs Standard Tariff — Which Saves More? 2026 UK Energy Comparison
Economy 7 tariffs charge a lower overnight rate (~15p/kWh) for 7 hours but a higher daytime rate (~40p/kWh). The standard flat rate is 34p/kWh all day. Economy 7 only saves money if 40% or more of your electricity usage is during the overnight period. It is ideal for homes with storage heaters, immersion water heaters, or EV chargers — but most modern homes are better off with a flat-rate or EV-specific tariff.
How Economy 7 Works
Economy 7 provides 7 hours of cheaper overnight electricity (typically 12am-7am or 1am-8am, varies by region and supplier). During these 7 hours, the rate drops to approximately 15p/kWh — less than half the standard rate. However, the remaining 17 daytime hours cost approximately 40p/kWh — higher than the standard 34p/kWh flat rate. This means using electricity during the day on Economy 7 is MORE expensive than a standard tariff. The system was designed for storage heaters and immersion heaters that run overnight.
When Economy 7 Saves Money
The break-even point is approximately 40% overnight usage. At 3,500 kWh annual usage: If 60% day / 40% night: Economy 7 costs £1,050 vs Standard £1,190 — saves £140. If 50% day / 50% night: Economy 7 costs £960 vs Standard £1,190 — saves £230. If 80% day / 20% night: Economy 7 costs £1,260 vs Standard £1,190 — costs £70 MORE. Best candidates for Economy 7: homes with electric storage heaters, electric immersion water heater on a timer, EV charging overnight, and dishwasher/washing machine on delay timers.
Economy 7 vs EV-Specific Tariffs
If you are considering Economy 7 primarily for EV charging, EV-specific tariffs are usually better: Octopus Intelligent Go: 7.5p/kWh overnight (vs 15p Economy 7). Octopus Go: 12p/kWh for 4.5 hours overnight. OVO Charge Anytime: ~8p/kWh overnight. These EV tariffs offer lower night rates than Economy 7 without the penalty of higher day rates. The daytime rate on Octopus Go is about 34-36p — same as standard, not the 40p+ of Economy 7. For EV-only needs, an EV tariff is almost always superior.
Economy 10 and Other Multi-Rate Tariffs
Economy 10: 10 hours of off-peak (typically 7 hours overnight + 3 hours afternoon). Better for homes that can use electricity during the afternoon off-peak window. Less common but available in some regions. Octopus Agile: Half-hourly variable pricing based on wholesale costs. Can be very cheap overnight (sometimes free or negative) but expensive during peak (50p+). Best for tech-savvy users with smart home automation. Octopus Cosy: Extra-cheap 4-hour off-peak windows, designed for heat pump users. Check what multi-rate tariffs are available in your area.
| Night Usage % | Economy 7 Cost | Standard Cost | Saving/(Loss) |
|---|---|---|---|
| 20% night | £1,260 | £1,190 | (£70) LOSS |
| 30% night | £1,155 | £1,190 | £35 saving |
| 40% night | £1,050 | £1,190 | £140 saving |
| 50% night | £960 | £1,190 | £230 saving |
| 60% night | £910 | £1,190 | £280 saving |
| 70% night | £840 | £1,190 | £350 saving |
How to Check Your Night Usage Percentage
If you have a smart meter, your supplier app shows half-hourly usage — add up overnight usage and divide by total. If you have a dual-rate meter (already on Economy 7), your bill shows separate day and night kWh readings — divide night by total. Rule of thumb: If you have storage heaters + immersion heater + EV, you likely use 50-60% overnight — Economy 7 will save money. If you only have an EV, switch to an EV-specific tariff instead. If you have gas central heating and no EV, Economy 7 probably won't save you money.
Disclaimer: For educational reference only. Consult a licensed professional.