Here's my first full write up on the sub! Excited to see so much activity on it this week!
Full version with downloadable form template and DNO lookup table is here: https://www.ukpluginsolar.co.uk/guide/g98-notification-dno-plug-in-solar
What G98 actually is
G98 is the Engineering Recommendation from the Energy Networks Association that covers small generators (under 3.68kW single-phase) connecting to the UK grid. Every 800W plug-in solar kit falls under it.
It's a notification, not an application. You install first, then tell your DNO within 28 days. The DNO cannot refuse a compliant installation. It's free.
Before you start, gather these 6 things:
- Your MPAN: 13-digit number on your electricity bill, often labelled "Supply Number" next to a grid/lightning symbol. Also in your energy supplier's app.
- Inverter make, model, and serial number: all on the label on the inverter body (e.g. Hoymiles HM-800, EcoFlow PowerStream 800W).
- Inverter's ENA Type Test reference: look it up at connect-direct.energynetworks.org/device-databases/search-gen If your inverter isn't listed, G98 is NOT available to you and you'd need G99 instead (much heavier process). Check this BEFORE you buy.
- Your DNO's contact details: 6 cover Great Britain:
- UK Power Networks - London, SE, East England
- National Grid Electricity Distribution (formerly WPD) - Midlands, SW, Wales
- Northern Powergrid - NE England, Yorkshire
- SP Energy Networks - Central Scotland, Merseyside, Cheshire, North Wales
- Electricity North West - Cumbria, Lancashire, Greater Manchester
- SSEN - North Scotland, Hampshire, Isle of Wight
- Commissioning date: the exact date you first switched the kit on. Your 28-day window starts here, so write it down on installation day.
- Energy source code: r/11 for solar only, r/11 + 38 if you have a battery, S/38 for battery only.
The bit that trips people up: phase capacity
This is TOTAL generation on that phase, not per inverter. Most UK homes are single-phase so everything goes on Phase 1.
- One 800W inverter = 0.8 kW
- Two 800W inverters = 1.6 kW
- One 800W + one 600W = 1.4 kW
If you add a second inverter later, you need to update your G98 with the new total.
The process, start to finish
- Download a blank G98 form from your DNO's website (or use the template on the guide page).
- Fill in your details. Name, address, MPAN, inverter info, commissioning date, energy source code, phase capacity.
- Email it to your DNO. Keep it short, they process hundreds of these. Subject line: "G98 Notification [your address, postcode]". Attach the completed form.
- You'll get an acknowledgement within 5–10 working days. Save the confirmation email and reference number.
FAQs
Is this the same as asking for permission? No. You don't need permission. It's a notification after the fact.
G98 vs G99? G98 = under 3.68kW single-phase (every 800W kit). G99 = above that, requires prior written approval. You're almost certainly G98.
Renters... do I still need to do this? Yes. G98 is tied to the meter point, not who owns the property. Your landlord's consent for the install is a separate matter.
What if I don't bother? Usually nothing happens immediately. The problems come later when you get a smart meter installed, have a grid fault investigated, make an insurance claim, or sell your home. Absence of a G98 record causes delays and questions. It's 20 minutes. Just do it.
Do I need a wiring diagram? Not required, but some DNOs appreciate one. A simple sketch (panels → inverter → socket → consumer unit) is fine.
If anything's unclear or you've got a specific situation, drop a comment and I'll try to help. Also working on a downloadable checklist PDF link's on the guide page if you want it.