Nobody in Hertford needs to ring the electricity network to have solar panels connected. The installer deals with UK Power Networks on your behalf, and the work follows a fixed sequence, from checking which network serves the address to filing paperwork after the system is switched on. Knowing that sequence helps you read a quote and spot a missing step.
This guide follows it for homes in SG13 and SG14, from Bengeo to Hertford Heath. For the roof, the conservation area and what an array generates, see our page on solar panels in Hertford; for where a unit goes and how storage changes the paperwork, our page on home batteries in Hertford.
Before the survey: which network?
Hertford’s town centre sits in UK Power Networks’ Eastern Power Networks licence area. The county’s cables and lines were managed by Eastern Electricity before UKPN, and the nearest other licence area, London Power Networks, is about 17 km from the town-centre point on the published boundaries. Even so, UKPN’s area checker confirms the network for any individual address, so we run it for yours. The network operator is not your energy supplier: it owns the cables, while your supplier sends the bills, and the two stay separate when panels go on a Hertford roof.
At the design stage: the 16 A line
The Energy Networks Association’s G98 standard covers type-tested generation up to and including 16 A per phase, or 3.68 kW. It is the inverter’s rating that counts, not the panels’. A 4 kW inverter, at 17.39 A, is just over the line. That matters in Hertford because many homes are flats or terraces: 30.5% of the town’s households live in flats and 29.8% in terraced houses (Census 2021), and a 19th-century terrace roof on Port Vale or George Street may take fewer panels than the national typical system. A modest array with a smaller inverter can stay within G98. A battery inverter added later counts towards the same total.
Before work starts: G99 approval, if needed
Anything above 16 A per phase needs a G99 application, approved before work starts. UK Power Networks says that if an installation’s maximum export, after any export limitation scheme, is under 5 kW, it will approve the application automatically. An export limitation is a setting or device that caps how much the system sends to the grid, whatever the panels and battery could produce. On a Hertford semi with room for a larger array, it can be the simplest way to stay on the automatic route. PVGIS puts a 4 kWp south-facing array in Hertford at about 479 kWh in June, roughly 16 kWh a day, so midsummer is when an export limit would actually bite.
If the supply cannot take it
Sometimes UK Power Networks finds that a supply is not sufficient for the extra load and needs to upgrade it first. If no upgrade is needed, UKPN says there is nothing for you to pay it; if one is, the cost and timing vary from project to project. On some older terraced streets a supply is looped, shared with a neighbour, and UKPN says a looped supply has to be re-planned with both households and may carry a charge. For a Hertford terrace this is one of the things the survey checks first.
After commissioning: notification and certificates
For a house or small business up to 69 kVA whose supply can take the equipment, UKPN’s Smart Connect service lets an approved installer simply notify it within 28 days of the installation; it handles G98 and G99 forms, solar PV and battery storage. G98 itself allows notification before commissioning or within 28 days after it. Then come your own papers: the MCS certificate and electrical certification arrive once the installation is registered. A Smart Export Guarantee tariff needs that MCS certificate and a meter that can take half-hourly export readings. Rates are set by each supplier and must be above zero under Ofgem’s rules; they change at short notice, so we never print one. Keep the certificates with your Hertford house deeds.
Flats: the building owner comes first
With 30.5% of Hertford households in flats, maisonettes or apartments, this step comes before all the others for many people. UK Power Networks says the building owner’s permission is needed before solar or storage work starts on a multi-occupied building. In practice that means the freeholder or management company agreeing to the roof, the cable route and who benefits from the output, before a network form is filled in.
When the grid goes down
A standard grid-tied system shuts down in a power cut, and a battery does the same unless backup has been designed in, with a backup-capable inverter or gateway, an automatic changeover and a separate circuit for the essentials. That is priced as its own line, so any quote should say in writing whether it is included. Ofgem’s 2024/25 figures for Eastern Power Networks, which cover the whole licence area rather than Hertford alone, show about 44.6 supply interruptions per 100 customers and about 32.5 minutes lost per customer over the year, down from 46.2 and 35.6 in 2023/24. Weigh the cost of backup against how much a cut would matter in your home.
Our guide to solar battery storage, explained covers how the pieces work together, and our guide to what is in a solar quote, line by line shows where these steps should appear. For neighbouring towns, see our solar panels in Hertfordshire hub.
Sources: UK Power Networks Open Data, licence boundaries (December 2024), and NESO, GIS boundaries for GB DNO licence areas (May 2024), town-centre point check; UK Power Networks, Our history, Areas we cover, Smart Connect, and Solar and storage: cost, time and what’s involved (read 15 October 2026); UK Power Networks, fuse upgrade guidance (looped supplies); Energy Networks Association, EREC G98 Issue 2 (10 March 2025); ONS, Towns and cities, characteristics of built-up areas, Census 2021 (table 5c), Hertford; East Herts Council, Hertford Conservation Area Appraisal and Management Plan (1 March 2017); PVGIS 5.3 (European Commission JRC), PVGIS-SARAH3 2005–2023, run 15 October 2026; Ofgem, Smart Export Guarantee; Ofgem, RIIO-2 Electricity Distribution annual report 2024 to 2025 and supplementary datafile (15 January 2026).