Fixed is simpler
A fixed tariff suits households that want predictable pricing and fewer daily checks.
- the household routine is fixed
- most usage happens around meal times and evenings
- there is no EV, battery, or major flexible load
- nobody wants to plan appliances around a chart
- budgeting stability matters more than chasing lower slots
Agile gives you more control
Agile becomes interesting when the household can move meaningful usage.
Running a dishwasher one hour later may only save a small amount. Charging an EV or battery during a low-price block can matter much more. The bigger and more flexible the load, the more useful Agile's half-hourly shape becomes.
The risk is the opposite: use a lot during expensive slots and Agile can compare badly even when the day has some cheap periods.
Why the fair comparison is hard
A fixed 24p/kWh rate and an Agile day averaging 24p/kWh are not the same thing.
With the fixed tariff, every kWh has the same unit rate. With Agile, the cost depends on when each kWh is used. A home using more overnight may do well. A home using more around the evening peak may not.
That is why a fair comparison needs usage timing, not only daily kWh.
Practical check
Use the Compare page in split mode. Estimate how much of your electricity is overnight, daytime, and peak. A smart meter CSV can make this more realistic.
Then check one or two real loads in the Appliance timer. A tariff can look good in theory but be awkward in practice if the cheap windows do not fit your routine.