Sixteen amps per phase is the line that decides how a Potters Bar solar system is connected to the grid. Below it, the installer can tell UK Power Networks up to 28 days after the job is commissioned; above it, UK Power Networks has to approve the application before any work starts. The installer handles the paperwork, but knowing where your system sits on that line explains the timing of a quote and why some quotes mention an export limit.
Potters Bar is a town of semis and detached houses: 46.5% of households in the built-up area live in semis and 17.7% in detached houses (Census 2021), and many of those roofs can take an array big enough to cross the line. For the roof itself and the conservation areas around The Royds and Darkes Lane, see our page on solar panels in Potters Bar.
Which network serves Potters Bar
UK Power Networks runs the electricity network across London, the South East and the East of England. Its history page records that Eastern Electricity once managed the cables and lines in Hertfordshire, and Potters Bar town centre sits well inside what is now its Eastern Power Networks licence area, far from the London boundary. The network operator is not your energy supplier: you keep buying electricity from whoever you choose, while UK Power Networks owns the wires your system connects to. EN6 also reaches into Welwyn Hatfield, Broxbourne and Enfield council areas, which changes the planning authority for some addresses but not the UK Power Networks process described here.
Below the line: G98
The Energy Networks Association’s G98 rule covers type-tested generation up to and including 16 A per phase, which is 3.68 kW. For a system that size, the installer notifies UK Power Networks before commissioning or no later than 28 days after it, and UK Power Networks’ Smart Connect service lets approved installers do that online for a house whose supply can take the equipment. A smaller array on one of the 12.5% of Potters Bar households in a terrace, or a compact battery on its own, can sit under the line.
Above the line: G99 and the 5 kW approval
Anything above 16 A per phase needs a G99 application approved before work starts. A 4 kW inverter, at 17.39 A, is just over, so a 4 kWp array on a 4 kW inverter lands on the G99 side; PVGIS 5.3 estimates such an array, facing due south in Potters Bar, would make about 3,977 kWh a year. In June 2024 UK Power Networks announced a process letting customers get approval for up to 5 kW of solar and battery storage, against the 3.68 kW industry standard, and its current guidance says it automatically approves an application where the maximum export, after any export limitation, is under 5 kW. On a Furzefield semi, in a ward where 61.6% of households live in semis, that usually makes G99 a step in the timetable rather than a hurdle.
Export limits and batteries
A battery adds inverter capacity, and UK Power Networks looks at the total. An export limitation scheme caps how much the system can send to the grid, whatever the panels and battery can produce, and UK Power Networks judges the application on that maximum export. A larger array on a detached Parkfield house, in a ward where 32.9% of households live in detached homes, can be paired with a battery and limited so its export stays under 5 kW. Whether a limit costs you any export depends on the design, and the survey sets that out before you commit; our guide to what size home battery you need explains how the battery side is sized.
Upgrades and who pays
UK Power Networks says the installer contacts it on your behalf, and that in some cases your supply may not be sufficient for the additional load, in which case it upgrades the supply first. Where no upgrade is needed there is nothing to pay UK Power Networks; where one is, it says cost and timing vary from project to project. With 71.9% of Potters Bar households owning their home outright, with a mortgage or through shared ownership (Census 2021, our sum), most can agree to any upgrade themselves, while the 23.2% in flats or maisonettes need the building owner’s permission before work starts.
Power cuts: the figures and what a battery does
Ofgem’s 2024/25 figures for the Eastern Power Networks licence area show about 44.6 supply interruptions per 100 customers and about 32.5 minutes lost per customer over the year, against 46.2 and 35.6 the year before. They cover the whole licence area, from Potters Bar out across the East of England, and Ofgem treats them as reported after severe-weather adjustments. On average that is fewer than one interruption per customer every two years (our arithmetic).
In a power cut, a standard grid-tied battery shuts down with the grid and the panels stop too, so an ordinary battery in an EN6 semi keeps nothing running. Backup has to be designed in from the start, with a backup-capable inverter or gateway, an automatic changeover and a separate circuit for the essentials, and it costs more. Our page on battery storage in Potters Bar covers where those units go in the town’s semis and detached houses.
Your part, and the installer’s
Your part is small: confirm who owns the building, tell the installer about any panels or battery already fitted, and keep the certificates you are given. The installer sizes the inverter, files the G98 notification or G99 application with UK Power Networks, and hands over the MCS and electrical certificates, which a Smart Export Guarantee tariff needs. Hertsmere is not on DESNZ’s Warm Homes: Local Grant list, so in Potters Bar a system is usually a privately funded job; our guide to solar panel payback time sets out how the figures are worked, and our solar panels in Hertfordshire hub covers the rest of the county.
Sources: UK Power Networks, Areas we cover, Our history, Smart Connect, Solar and storage: cost, time and what’s involved, and news release of 10 June 2024 (Instant approval for over 90% of green installers); UK Power Networks Open Data licence boundaries (December 2024); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025 and supplementary datafile (published 15 January 2026); ONS, Towns and cities: characteristics of built-up areas, Census 2021, tables 5c and 6c (Potters Bar, E63004573); ONS Census 2021, TS044 by 2022 ward (Furzefield, Parkfield); postcodes.io outcode lookup for EN6 (ONS Postcode Directory data); PVGIS 5.3 (European Commission JRC), PVGIS-SARAH3 2005–2023, run 15 October 2026; GOV.UK, Warm Homes: Local Grant successful local authorities (updated 2 July 2026); Ofgem, Smart Export Guarantee.