What is a dynamic energy tariff?
A dynamic energy tariff is one where your unit rate moves with the wholesale electricity market, sometimes every 30 minutes, instead of sitting fixed for months on end. Octopus Agile is the best known example in the UK. A handful of other suppliers now run similar half hourly pricing plans too.
The idea is simple enough. Electricity is cheapest when the grid has plenty of it, windy nights, sunny afternoons, and priciest at teatime when everyone’s kettle, oven and telly are on at once. A dynamic energy tariff passes that swing straight through to your bill instead of smoothing it into one flat rate.
How do dynamic energy tariffs actually work?
Your supplier publishes the next day’s prices in the afternoon, typically between 4pm and 8pm, covering every half hour slot from midnight to midnight. You’ll always know your rate several hours ahead at least, so you can plan around it rather than guess.
Overnight rates on dynamic energy tariffs often sit in the low single digits per kWh. The early evening peak can run several times higher. A handful of times a month, when wind generation floods the grid, prices dip below zero and some suppliers pay you to use power during that window. Don’t bank on it though. It won’t happen every day.
Dynamic energy tariffs vs the standard price cap
Here’s how the two compare on paper, checked against Ofgem’s price cap for July to September 2026.
Standard tariff vs dynamic tariff at a glance
| Standard variable (price cap) | Dynamic energy tariff | |
| Electricity rate | Fixed at 26.11p/kWh (direct debit, Jul-Sep 2026) | Changes every 30 minutes with wholesale prices |
| Standing charge | 57.19p a day | Usually similar, set by the supplier |
| Meter needed | Any meter | Smart meter (SMETS2 or upgraded SMETS1) |
| Best for | Households who want one predictable number | Households who can shift usage to cheap windows |
That price cap figure is the ceiling suppliers can charge on a standard variable tariff, not a promise of what you’ll actually pay. Your bill still comes down to how much energy you use.
Do you need a smart meter for a dynamic energy tariff?
Yes. Dynamic energy tariffs bill you on what you actually used in each half hour slot, so your supplier needs half hourly readings to work out the total. No working smart meter, no dynamic tariff, most suppliers simply won’t let you join. And if your meter drops back to manual mode, you could get moved onto a standard rate until it’s fixed.
A rough worked example
Say a household runs an EV charger and a tumble dryer, both overnight. On a standard tariff, every unit costs the same 26.11p, whatever time the clock says. On a dynamic energy tariff, shifting that same usage into the cheapest overnight window could bring the effective rate down considerably. How much depends on the supplier, the weather, and how consistently you actually stick to the plan.
Flip it round for a household that’s out all day and does everything between 5pm and 9pm. A dynamic energy tariff can end up costing more than the price cap rate in a bad month. There’s no single answer here, it comes down to your own usage pattern, not the tariff’s reputation.
Are dynamic energy tariffs worth it for your household?
It depends entirely on whether you can move your usage around. Charge an electric car overnight, run a home battery, or put the washing machine on at 2am without waking the street, and a dynamic energy tariff can work in your favour most months.
If your day looks like everyone else’s though, cooking dinner and running the heating between 5pm and 8pm, you’re using power exactly when a dynamic energy tariff is at its most expensive. A fixed or standard tariff is probably the simpler, safer choice there.
This is the Do Nothing Default working against you either way. Staying on a tariff that doesn’t suit how you actually live costs money quietly, whichever direction the mismatch runs.
Key takeaways
- A dynamic energy tariff changes your unit rate roughly every 30 minutes, based on wholesale prices.
- You’ll need a working smart meter to join one.
- They tend to suit EV owners, battery owners and night owls, not typical 5pm to 8pm households.
- Prices are published a day ahead, so you always get some warning.
- Compare your likely usage pattern against a standard tariff before switching, not just the headline overnight rate.
Whichever way you lean, it’s worth checking what you’re on right now. Ofgem publishes the current price cap figures every quarter, and our energy price cap guide breaks down what that means for your bill. Not sure who the biggest suppliers even are? Our guide to the big 6 energy providers is a good place to start.
Frequently asked questions about dynamic energy tariffs
- Can I switch back if a dynamic energy tariff doesn’t suit me?
- Yes. You can switch away like any other tariff, just check whether your current deal has an exit fee first.
- Do dynamic energy tariffs affect gas as well as electricity?
- Most dynamic energy tariffs only apply to electricity. Gas is usually billed on a separate, steadier rate from the same supplier.
- Is a dynamic energy tariff riskier than a fixed deal?
- It carries more uncertainty than a fixed rate, since your monthly total isn’t set in advance. Households with predictable, shiftable usage tend to find that risk manageable.
- What happens if my smart meter stops sending readings?
- Your supplier can’t bill a dynamic energy tariff accurately without half hourly data, so you might get moved to a standard rate until the meter’s fixed.
- How much notice do I get of tomorrow’s prices?
- Suppliers typically publish the next day’s half hourly rates in the afternoon, so you’ll usually know your prices several hours ahead at least.
