Agile prices and home batteries in South Wales
Region K is served by National Grid (South Wales). Over the last 12 months Agile averaged 22.8p per kWh here, the 11th cheapest of the 14 regions, and the gap between each day’s cheapest and dearest half-hour averaged 29.2p — the 7th widest in Great Britain. That gap is what a battery earns from.
Every half-hour of the year
The average day
All 48 half-hours
| Time | p/kWh | Time | p/kWh |
|---|---|---|---|
| 00:00 | 19.7p | 12:00 | 17.2p |
| 00:30 | 20.0p | 12:30 | 16.9p |
| 01:00 | 19.3p | 13:00 | 17.0p |
| 01:30 | 18.9p | 13:30 | 16.7p |
| 02:00 | 18.9p | 14:00 | 17.1p |
| 02:30 | 18.3p | 14:30 | 17.1p |
| 03:00 | 18.4p | 15:00 | 17.9p |
| 03:30 | 17.9p | 15:30 | 19.2p |
| 04:00 | 18.6p | 16:00 | 33.5p |
| 04:30 | 18.3p | 16:30 | 36.0p |
| 05:00 | 19.9p | 17:00 | 38.0p |
| 05:30 | 20.1p | 17:30 | 39.6p |
| 06:00 | 21.5p | 18:00 | 40.9p |
| 06:30 | 23.4p | 18:30 | 41.2p |
| 07:00 | 22.7p | 19:00 | 28.4p |
| 07:30 | 24.3p | 19:30 | 27.8p |
| 08:00 | 22.5p | 20:00 | 27.1p |
| 08:30 | 22.6p | 20:30 | 26.1p |
| 09:00 | 21.4p | 21:00 | 26.0p |
| 09:30 | 20.4p | 21:30 | 24.1p |
| 10:00 | 19.4p | 22:00 | 23.4p |
| 10:30 | 18.5p | 22:30 | 21.2p |
| 11:00 | 17.9p | 23:00 | 21.5p |
| 11:30 | 17.3p | 23:30 | 20.2p |
Prices were lowest in Apr (average 17.2p) and highest in Sep (29p). The single cheapest half-hour was -12.1p and the dearest 94.5p.
Month by month
| Month | Average Agile price |
|---|---|
| Jan | 23.5p |
| Feb | 20.1p |
| Mar | 23.5p |
| Apr | 17.2p |
| May | 22.3p |
| Jun | 21.1p |
| Jul | 22.8p |
| Aug | 27.9p |
| Sep | 29p |
| Oct | 27.3p |
| Nov | 19.6p |
| Dec | 19p |
Selling back: Agile Outgoing
Agile Outgoing paid an average of 11.1p per kWh in South Wales over the same year, and 17.6p between 16:00 and 19:00. It pays for exports from MCS-certified solar, not from a battery and not from plug-in solar.
Other tariffs in South Wales
| Tariff | Standing charge, p/day | Unit rates, p/kWh |
|---|---|---|
| Flexible Octopus | 57.17 | 27.9p |
| Agile Octopus | 62.06 | average 22.8p |
| Octopus Go | 57.08 | 9.9p / 36.2p |
| Intelligent Octopus Go | 57.08 | 6.9p / 37.9p |
| Cosy Octopus | 57.08 | 14.8p / 30.2p / 45.3p |
| Octopus Flux | 57.08 | 16.9p / 28.1p / 39.2p |
Octopus public API, fetched 25 October 2026; import prices with 5% VAT.
Plug-in solar in South Wales
For Cardiff, PVGIS (European Commission JRC) gives about 596 kWh a year from 800 W of upright south-facing balcony panels and 833 kWh angled at 35°. Check the payback and get permission letters.
Frequently asked questions
When is electricity cheapest on Agile in South Wales?
Over 25 October 2025 to 25 October 2026, the cheapest three hours on an average day in region K were 12:00–15:00, averaging 17p per kWh, against 38.2p from 16:00 to 19:00. 3% of half-hours were below zero.
Is a home battery worth it on Agile in South Wales?
In Fortyeight’s model a typical 2,500 kWh home in South Wales saves about £226 a year with a 10 kWh battery on Agile, so the battery would need to cost under £2,054 to pay back in 10 years. Bigger or more evening-heavy users save more; run your own data to check.
How much would an 800 W plug-in solar kit make in South Wales?
PVGIS data for Cardiff give about 596 kWh a year for 800 W of upright, south-facing balcony panels and 833 kWh angled at 35°, before shading.
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