South East England is covered by UK Power Networks (Kent, East Sussex and parts of Surrey and West Sussex) and SSEN (Hampshire, Berkshire, Oxfordshire and the west of Surrey and West Sussex). DESNZ counts 253,139 domestic solar installations in the region, the most in Britain. In this site's model a 10 kWh battery added to 4 kWp of solar on Octopus Flux saves about £435 a year in the UK Power Networks area and £421 in the SSEN area.
Your electricity region and network operator
South East England spans 2 electricity regions, each with its own prices and network operator:
| Electricity region | Network operator (DNO) | Flat unit rate | Standing charge (pence a day) |
|---|---|---|---|
| South East England (J) | UK Power Networks (South Eastern Power Networks) | 26.67p/kWh | 51.16 |
| Southern England (H) | SSEN (Southern Electric Power Distribution) | 26.42p/kWh | 46.41 |
What a battery can buy low and use high
The rates that decide a battery's saving in South East England:
| Rate | South East England | Southern England |
|---|---|---|
| Octopus Flux import, 2am to 5am | 15.49p | 15.34p |
| Octopus Flux import, 4pm to 7pm | 36.13p | 35.78p |
| Octopus Flux export, 4pm to 7pm | 29.79p | 29.00p |
| Octopus Go overnight import | 8.62p | 8.62p |
| Octopus Go daytime import | 31.38p | 31.29p |
| Outgoing Octopus flat export | 12.00p | 12.00p |
| Agile Octopus, average of each day's cheapest 3 hours | 15.16p | 14.31p |
| Agile Octopus, average 4pm to 7pm | 46.83p | 45.11p |
| Flux spread: peak import minus off-peak | 20.64p | 20.44p |
Solar yield across South East England
Modelled output of a 4 kWp south-facing array:
| Place | kWh a year | June | December | Electricity region |
|---|---|---|---|---|
| Brighton | 4,624 | 573 | 156 | South East England |
| Southampton | 4,255 | 518 | 145 | Southern England |
| Reading | 4,084 | 494 | 140 | Southern England |
| Canterbury | 4,393 | 535 | 149 | South East England |
| Oxford | 4,071 | 489 | 138 | West Midlands / Southern England |
How often the power goes off
Ofgem's reliability figures for the networks serving South East England (lower is better):
| Network area | Interruptions per 100 customers | Minutes lost per customer | Against the GB average |
|---|---|---|---|
| South Eastern England | 42.19 | 30.37 | Close to average |
| Southern England | 41.85 | 51.18 | More minutes lost |
Solar already on South East England's roofs: DESNZ counts 253,139 domestic-scale solar installations in South East England (1,067.5 MW) at the end of Jul 2026.
A home in Brighton using 3,000 kWh a year, with 4 kWp of solar, adds a 10 kWh battery. Yearly savings with Brighton's solar yield and South East England rates, against no battery on a flat tariff:
| Tariff with the battery | Modelled saving a year | Energy charged from the grid |
|---|---|---|
| Octopus Flux, selling spare stored energy at the peak | £434 | 1,039 kWh |
| Staying on a flat tariff (solar storage only) | £185 | 0 kWh |
| Same home with no solar, battery on Agile Octopus | £287 | 3,258 kWh |
| Same home with no solar and an electric car, battery on Octopus Go | £498 | 3,258 kWh |
Flux needs solar panels and Go is for electric car owners. How the model works · try your own numbers.
Two networks, one region
The South East is the only English region split between two different network companies, and the split matters in three ways:
- Tariff rates. Octopus prices the two areas separately. On 26 September 2026 the Flux peak was 36.13p in the UK Power Networks South Eastern area and 35.78p in SSEN’s Southern area, and the standing charges were 51.16p and 46.41p a day.
- Connection rules. Each operator handles G98 notifications and G99 applications its own way. SSEN’s fast-track process aims for a decision in ten working days and says you cannot connect until it confirms its assessment. UK Power Networks automatically approves applications where the maximum export is under 5 kW.
- Reliability. Ofgem’s 2024/25 figures put SSEN Southern at 51.18 minutes lost per customer and UK Power Networks South Eastern at 30.37, with similar numbers of interruptions (41.85 and 42.19 per 100 customers).
The boundary runs through Surrey and West Sussex rather than along a county line, and parts of Oxfordshire border the West Midlands area too, so check your own postcode.
The retrofit capital
DESNZ counted 253,139 domestic-scale solar installations in the South East at the end of July 2026, the most of any UK region, with 1,067.5 MW between them. Many of those systems were fitted years ago without a battery and export much of their summer output. That is the textbook case for an AC-coupled battery retrofit: the panels stay, a battery with its own inverter goes alongside, and Octopus Flux, which needs solar panels, becomes available. See adding a battery to existing solar.
Sunnier than most of Britain
PVGIS gives a 4 kWp south-facing array 4,624 kWh a year in Brighton, 4,393 in Canterbury and 4,255 in Southampton, among the highest figures anywhere in Great Britain. Even the South East’s December output (about 140 to 156 kWh a month in these towns) is well above Scotland’s. The modelled saving of about £435 a year for a 10 kWh battery with solar on Flux in the UK Power Networks area is the second-highest of the fourteen regions.
Funding in the South East
The South East follows the rules for England: 0% VAT on installed batteries until 31 March 2027, the Warm Homes Loan Scheme for lower-interest loans of up to £15,000, and, for eligible low-income homes, a council’s Warm Homes: Local Grant, which can include a battery only alongside solar panels. There is no regional battery grant. See grants and funding.
Getting quotes
Tell installers whether you already have solar and, if so, the inverter make and size; it decides between an AC and DC retrofit. Ask each quote to confirm which network it will notify and whether an export limit applies. Compare battery storage quotes on usable kWh and price per kWh before committing.
Home batteries in South East England: questions
Which network operator covers my home in the South East?
It depends on your postcode, not your county. UK Power Networks runs the South Eastern licence area (much of Kent, East Sussex and eastern Surrey and West Sussex) and SSEN runs the Southern area (Hampshire, Berkshire, Oxfordshire and western parts of Surrey and West Sussex). Oxford postcodes can fall on the boundary with the West Midlands area. Use the postcode lookup in the calculator or ask your installer.
Is the South East good for solar and battery storage?
It has some of the highest yields in Britain. PVGIS models a 4 kWp south-facing array at 4,624 kWh a year in Brighton and 4,393 in Canterbury, against about 3,800 in Leeds. More summer surplus means more for a battery to store.
Do power cuts differ across the South East?
Yes. In Ofgem's 2024/25 figures SSEN's Southern area lost 51.18 minutes per customer, against 30.37 minutes in UK Power Networks' South Eastern area, with similar numbers of interruptions. If backup matters to you, check which network you are on.