Ask a Weybridge household what stands between them and a home battery and the answer is often ‘permission from the electricity board’. Sometimes the network operator does have to approve a battery before it goes in; more often it only has to be told. What decides it is the size of the inverter, not the size of the house or the battery. Our page on battery storage in Weybridge covers where a unit sits in the town’s homes, from Oatlands semis to St George’s Hill plots. This guide covers the grid side.
Weybridge town centre sits in UK Power Networks’ South Eastern Power Networks licence area. On the boundary data published by UK Power Networks and the National Energy System Operator, the nearest other network, SSEN’s Southern Electric area, begins about 3.5 km from the centre, so homes towards the western fringe of KT13 should confirm their operator by postcode. The operator owns the cables and the service head in your meter cupboard. It is not your energy supplier, and switching supplier does not change it.
The line that decides it: 16 amps per phase
The Energy Networks Association’s G98 rule covers type-tested equipment up to and including 16 A per phase, which is 3.68 kW on a normal single-phase house supply. Within that limit the installer notifies UK Power Networks before commissioning or no later than 28 days after it. Anything above 16 A per phase needs a G99 application, approved before the work starts. A 4 kW inverter draws 17.39 A, so it is already over the line.
That matters in Weybridge because the houses are large. Across Elmbridge, 32.6% of households live in detached houses (Census 2021), and bigger homes tend to prompt bigger battery inverters. If a roof in Brooklands or Oatlands already has panels, the existing inverter and the new battery are counted together, so a modest battery added to a mid-sized array can still tip the property into G99.
Three examples of how the rules apply
The three Weybridge cases below are illustrations of the rules, not past jobs. A semi in Oatlands adding a battery on a 3.68 kW inverter, with no panels yet: a G98 notification, sent by the installer through UK Power Networks’ Smart Connect portal, which approved installers use for G98 and G99 forms covering solar PV and battery storage.
A detached St George’s Hill house with an existing array and a 5 kW battery inverter: over 16 A per phase, so a G99 application approved before work. UK Power Networks says it automatically approves applications where the maximum export, after any export limitation, is under 5 kW.
A larger system on a big Weybridge plot: here UK Power Networks may find the supply cannot take the extra load and needs upgrading first. If no upgrade is needed there is nothing to pay UK Power Networks; if one is, it says the cost and timing vary from project to project.
What an export limit actually does
An export limit is a setting, backed by a meter on the incoming supply, that caps how much power the system pushes onto the network at any moment. It does not cap what the house can use. PVGIS puts a 4 kWp, due-south roof in Weybridge at about 484 kWh in June, roughly 16 kWh a day, and about 136 kWh in December, roughly 4.4 kWh a day (our arithmetic on the monthly figures). On a bright June afternoon the battery fills first and the limit only bites on what is left over. In December there is rarely enough spare to reach it. Sizing the battery itself is covered in our guide to what size home battery you need.
How often does the South Eastern network go off?
Ofgem publishes reliability figures for each licence area, not for each town. For South Eastern Power Networks in 2024/25 they show about 42.2 supply interruptions per 100 customers and about 30.4 minutes lost per customer over the year, both inside Ofgem’s targets of 42.5 and 31.2. The year before, the figures were 49.5 and 36.5. Ofgem notes that severe-weather adjustments were applied before its final assessment, so treat these as reported figures for the wider area that includes Weybridge.
Backup is a design choice, not a default
A standard grid-tied battery shuts down when the grid goes down. It will not keep a Weybridge kitchen or boiler running in a power cut unless the system was designed for backup from the start: a backup-capable inverter or gateway, a dedicated backup circuit for the loads you choose, and the switching that separates the house from the network safely. That costs more, and on a large plot where the battery sits in a detached garage, the extra wiring back to the house adds to it. Set the cost against roughly half an hour of lost supply a year across the South Eastern area, and decide whether backup earns its place.
The main fuse, the car and the battery together
Plug-in cars are a growing part of the picture. DVLA records 6,523 privately kept plug-in vehicles across Elmbridge at the end of June 2026, up from 5,249 a year earlier, about 24% more (our arithmetic). A 7.4 kW charger draws 32 A continuously, and most homes have a 60 A, 80 A or 100 A main fuse. UK Power Networks says it can upgrade a main fuse from 30 or 60 A to 80 or 100 A, and load management usually avoids that. If a Weybridge household adds a charger and a battery in the same year, the installer should look at the supply once, not twice.
What to ask any installer
Ask which route your system needs, G98 or G99, and whether an export limit is part of the design; on a large Weybridge house with panels already up, ask how the existing inverter was counted. Ask who submits the forms to UK Power Networks and when. Ask whether backup is included, and what it would cost if not. Residential battery installations carry 0% VAT until 31 March 2027 and 5% from 1 April 2027, whether fitted with panels or on their own. If you have no panels, our guide to battery storage without solar panels covers the tariff arithmetic. If the roof is still undecided, start with solar panels in Weybridge, and our solar panels in Surrey hub covers the wider county.
We are a NAPIT member (73495) and MCS-certified for solar PV and battery storage, with certification held via NAPIT, and on a Weybridge job the G98 or G99 paperwork to UK Power Networks is ours to submit, not yours. You can ask for a survey through our contact page.
Sources: UK Power Networks, licence boundaries open data (December 2024); National Energy System Operator, GIS boundaries for GB DNO licence areas (May 2024); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); UK Power Networks, Smart Connect and Solar and storage: cost, time and what’s involved (read 15 October 2026); Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025 and supplementary datafile (15 January 2026); PVGIS 5.3, European Commission Joint Research Centre (PVGIS-SARAH3 2005–2023; 4 kWp, 35°, due south, 14% losses; Weybridge run 15 October 2026); ONS Census 2021, TS044 accommodation type, Elmbridge; DfT and DVLA, VEH0142 licensed plug-in vehicles, 2026 Q2 and 2025 Q2 (published 23 September 2026); HMRC, VAT Notice 708/6. Daily and percentage figures are our arithmetic.