Helpful video reference. We reference "Plug-In Solar Is NOW Legal in the UK" as the video reference for this guide. It covers the UK-specific regulatory change correctly, including the G100 DNO notification requirement and the 800 W limit that applies under the August 2026 amendment.
1. Understand the rules: what is allowed and what is not
The August 2026 amendment to Part P of the Building Regulations created a new permitted development category for small-scale plug-in solar systems. The key limits are:
- Maximum output: 800 W per phase (typically one or two standard 400 W panels with a single micro-inverter)
- Connection method: plug-in only, via a standard 13 A socket. No hardwiring is permitted under this exemption
- DNO notification: you must submit a G100 self-notification to your Distribution Network Operator before connecting
- Listed equipment: the micro-inverter must be G100-compliant and carry a CE or UKCA mark
If you want more than 800 W, or if you want to hardwire the inverter, you move into full Part P notifiable territory and need either a registered electrician or a competent person scheme registration.
2. Choose a suitable socket
The socket choice matters. Ideally, use one on a dedicated radial circuit rather than a busy kitchen ring final that already carries several appliances at once. Avoid spurs taken from behind a fridge or washing machine where access is difficult and the socket sees high-ambient-temperature conditions.
The socket should be rated at 13 A, in good mechanical condition (no cracks, the shutters should spring back cleanly), and protected by an RCD. Most modern consumer units give RCD protection on all circuits, but if yours is an older board with only some circuits protected, confirm the socket you intend to use is on a protected circuit before you connect generation equipment to it.
3. Site the panels and mount the brackets
South-facing or within 45 degrees of south is best. Shade from chimneys, neighbouring buildings, or overhanging trees will reduce output significantly. For a flat on a communal block, check the lease before drilling into any shared structure: many leases require freeholder consent for external fixings.
Fix the mounting brackets according to the manufacturer's instructions. For balcony rail mounting, the clamp system supplied with the kit is usually sufficient. For wall mounting, use appropriate fixings for the substrate: masonry anchors in brick or block, not just the supplied screws into render.
4. Run the cable from panels to the micro-inverter
Connect the panel DC output cables to the micro-inverter using the supplied MC4 connectors. Route the cable so it is not pinched, not across sharp edges, and not where it will be walked on. Secure it with cable clips or cable ties at regular intervals. Keep the DC cable run as short as practical.
The micro-inverter will usually mount under the panel or on the underside of the bracket. Ensure it is accessible for any future inspection and not in a location where water can pool around it.
5. Connect the micro-inverter output to the socket
Use the AC output cable and safety plug supplied with the inverter. Plug it into the chosen mains socket. Do not modify the plug, cut the lead short, or replace the supplied plug with a different one. The plug supplied with a G100-compliant inverter is designed with a specific current rating and safety interlock.
The system will not energise until it has synchronised with the grid frequency: this takes between 30 seconds and two minutes on initial connection. You should hear the inverter fans run briefly and then the monitoring LED (or app) will confirm generation has started if sunlight is present.
6. Submit a G100 DNO self-notification
Before energising, log on to your Distribution Network Operator's website and complete the G100 self-notification form. In east Kent, your DNO is UK Power Networks. The form asks for your address, the installed capacity in kW, and the inverter model. It takes around ten minutes. You will receive an acknowledgement by email: save a copy.
The G100 process is free and does not require any technical inspection. It is not optional: connecting generation equipment to the grid without notifying the DNO is a breach of the Grid Code and could void your home insurance in the event of a claim related to the installation.
7. Monitor output and check the system after 30 days
Most micro-inverters include a monitoring app. Check generation figures after the first full sunny day to confirm the system is working. After 30 days, inspect the cable fixings, the socket face, and the inverter housing for any signs of heat or discolouration. A socket that is warm to the touch after a period of generation is not normal and should be inspected.
When to call us
If you want more than 800 W, want to add battery storage, or want a proper hardwired solar PV installation rather than a plug-in system, that is a full electrical job. Richard can survey your property, size a system, handle the Part P certification, and submit the full G98 or G99 DNO application for you.
Want a full solar PV system in Sandwich?
Richard installs solar PV and battery storage across east Kent, fully Part P certified and MCS-registered.
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