Epping’s town centre is about 3.8 km from a line most residents never think about: the boundary between two of UK Power Networks’ licence areas. On NESO’s maps, the town-centre point sits in the Eastern Power Networks area and the London Power Networks area begins about 3.8 km away. Both are run by UK Power Networks, so the rules below are the same either way, but if you live towards the edge of town, UKPN’s postcode area checker is the quick way to confirm which licence your address is in.
This guide covers the grid side of solar for a CM16 home: who tells the network, the 3.68 kW line, export limits, adding a battery and what really happens in a power cut. For generation, planning around the High Street and Bell Common, and cost, see our page on solar panels in Epping.
Who owns the wires
The network operator owns the cables and substations that bring power to your house; it is not the company that bills you. Before UK Power Networks, Eastern Electricity managed the cables and lines across Essex, and in Epping the operator today is UK Power Networks whichever side of the licence boundary you are on. Your supplier can change; your network operator does not.
The 3.68 kW line
The rule comes from the Energy Networks Association. Type-tested generation up to and including 16 A per phase, which is 3.68 kW on a normal single-phase house supply, is notified under G98, before commissioning or no later than 28 days after it. Anything above that needs a G99 application approved before the work starts. A 4 kW inverter, at 17.39 A, is just over the line.
The figure that counts is the inverter’s rating, not the panels’ peak output, and for a battery added later it is all the inverters together. Epping’s commonest homes are semis, 34.0% of households in the built-up area at Census 2021, with 19.0% in detached houses, and if the survey of a larger roof points to an inverter above 3.68 kW, expect a G99 approval before work starts; it is routine. The installer files it through UK Power Networks’ Smart Connect service, which handles G98 and G99 forms for domestic solar and battery storage.
Export limits and the 5 kW figure
UK Power Networks says it automatically approves an application where the installation’s maximum export, after any export limitation, is under 5 kW; in June 2024 it described this as significantly higher than the industry standard of 3.68 kW. An export limit is a setting that caps what the system sends to the grid at any moment. It does not cap what the panels make for the house, and with a battery some of that surplus can be stored instead.
If no supply upgrade is needed, there is nothing for an Epping homeowner to pay UK Power Networks. If one is, it says the cost and timing vary from project to project. Most homes have a 60 A, 80 A or 100 A main fuse, and UKPN says it can upgrade a 30 A or 60 A fuse to 80 or 100 A where one is needed; the survey checks yours first.
Adding a battery later
A battery brings its own inverter unless the system uses a hybrid one, and the network looks at the total. An array that went in under G98 can cross into G99 once storage is added, which means an approval before the battery goes in rather than a notification afterwards. That is routine paperwork for the installer, not a reason to avoid storage. DESNZ records about 2,348 solar PV installations of all sizes across Epping Forest district at the end of 2025, and any of them that gains a battery goes through the same check. For where a unit fits in an Epping semi, terrace or listed cottage, see our page on battery storage in Epping, and for sizing, our guide to what size home battery you need.
What the reliability figures say
Ofgem publishes reliability figures for each licence area. For Eastern Power Networks in 2024/25, they show about 44.6 supply interruptions per 100 customers and about 32.5 minutes lost per customer over the year, planned and unplanned, against 46.2 and 35.6 the year before. Across all of Great Britain’s licence areas the figures were about 39.7 and 35.1. Read plainly, the average Eastern customer had fewer than one interruption every two years and lost about half an hour of supply across the year (our arithmetic). These are figures for the whole Eastern area, not for Epping’s streets, and Ofgem notes they were adjusted for severe weather before its final assessment.
Power cuts: panels, batteries and backup
A grid-connected solar inverter switches off when the network does, so that it cannot feed power into cables engineers may be working on. A standard grid-tied battery shuts down too, even when it is full. So in a power cut, an Epping house with panels and a battery goes dark like its neighbours, unless backup was designed in from the start.
Backup needs extra switching equipment beside the meter that separates the home from the network, and a choice of circuits to keep running. It changes the wiring and the price, and it is a decision to make at the quote, never a default to assume. On a listed High Street house or one of Bell Common’s listed weatherboarded cottages, that extra kit is something more to fix to the building, so listed building consent comes into it as well. Ask any installer, us included, to state in writing whether backup is included.
What to have ready for the survey
A recent bill, so the supplier and meter type are clear; a photo of the meter and consumer unit; and, if you know it, the main fuse rating. Across Epping Forest district, 742 households (1.4%) lived in a caravan or other mobile or temporary structure at the 2021 Census; on a park home, the site owner’s rules and the supply arrangement come before any of the above. Our guide to what is in a solar quote, line by line shows where the network items should appear, and neighbouring towns are on our solar panels in Essex hub.
Sources: UK Power Networks, licence boundaries open dataset (17 December 2024), Our history, Areas we cover (area checker), Smart Connect, Solar and storage: cost, time and what’s involved, Instant approval for over 90% of green installers (10 June 2024) and fuse upgrade guidance; NESO, GIS boundaries for GB DNO licence areas (3 May 2024); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025 and supplementary datafile (15 January 2026); ONS, Towns and cities, characteristics of built-up areas, Census 2021 (table 5c), and Census 2021 TS044 Accommodation type, Epping Forest (Nomis); DESNZ, Renewable electricity by local authority, 2014 to 2025 (published 29 September 2026), Epping Forest; Epping Forest District Council, Conservation areas.