What to know before getting solar panels: the honest checklist

Helpful video reference. We use Artisan Electrics' UK tutorial "Don't get Solar PV until you've watched this video!" as the video reference here. Artisan Electrics are a Cambridge-based electrical firm with a large UK following, and this video covers the consumer pitfalls that sales materials tend to gloss over. Worth watching before you take the first call from an installer.

1. Assess your roof before anything else

Roof orientation and shading are the two biggest factors in what your system will actually generate. South-facing is ideal, but southwest and southeast roofs perform well too. East or west-only roofs generate less on average but can suit households with high morning or evening demand. North-facing roofs are rarely worth the investment.

Check for shading. A chimney that casts a shadow over part of the roof for a few hours a day can reduce generation by more than you would expect, especially with a string inverter where one shaded panel affects the whole string. A nearby tree that looks small now will be larger in ten years.

Also check the condition of the roof covering. Panels are designed to last 25 years. If the tiles or felt underneath need work in the next five years, do that first - removing and refitting panels doubles the cost of roofing work.

2. Check your consumer unit and earthing arrangement

A modern all-RCBO consumer unit makes connecting a solar inverter straightforward. The installer will need a free way to add a new circuit, and the incoming supply needs to be adequate for the system size proposed.

Older split-load boards with a single shared RCD and some plain MCBs can work, but they may need upgrading if the solar installation pushes you above the board's capacity. A rewireable fuse box is almost certainly due for replacement before solar is added.

Earthing matters too. The majority of UK homes are on a TN-C-S (PME) supply, where the earth and neutral are combined in the supply cable. Solar inverters on a TN-C-S supply need open PEN fault protection under BS 7671 and the relevant DNO guidelines. Rural properties in east Kent sometimes have a TT earthing arrangement, which requires a different approach to the inverter earth fault detection. Any competent MCS installer will know this - but ask if they have confirmed your earthing type.

3. Understand the DNO notification rules

In England, your Distribution Network Operator (DNO) must be notified before you export solar electricity to the grid. The rules depend on system size:

• Up to 3.68 kW per phase (most domestic 4 kW systems): G98 notification only. The installer submits this and you do not need to wait for approval before commissioning.
• Above 3.68 kW per phase: Full G99 application required. This involves technical information about the inverter and can take four to six weeks for the DNO to process. You cannot legally export until it is approved.

If an installer proposes a 6 kW system and does not mention G99, ask them directly. Some installers are willing to limit the inverter export to 3.68 kW to avoid the G99 process - which may or may not suit you depending on the system design and battery plans.

4. Get at least three MCS-certified quotes and compare them properly

MCS (Microgeneration Certification Scheme) certification is not optional. Without it, you cannot register for the Smart Export Guarantee and you will not have the warranty protection the scheme provides. Check any installer's MCS number on the MCS database before you agree to a survey.

When comparing quotes, look beyond the headline price and system size:

• Panel brand and model, wattage per panel, and the manufacturer's product and power warranties (typically 12-15 years for product, 25 years for power output)
• Inverter type: string inverters are cheaper; microinverters and DC optimisers cost more but handle partial shading better
• Roof fixings and waterproofing: the quality of the flashings and brackets matters for long-term watertightness
• Scaffolding included or quoted separately
• Monitoring app and what data it gives you
• Whether the quote includes the DNO notification fee

5. Find your best Smart Export Guarantee rate before the panels go on

The Smart Export Guarantee (SEG) pays you for every unit of electricity you export to the grid. Licensed energy suppliers with 150,000 or more customers must offer a SEG tariff, and many others do voluntarily.

Rates vary considerably. Fixed-rate SEG tariffs typically pay between 3p and 15p per kWh. Time-of-use SEG tariffs can pay more during afternoon periods when grid demand is high. The difference over a 25-year panel lifetime is not trivial.

You can switch SEG supplier independently of your import tariff. Check the Ofgem database or comparison tools, apply before the system is commissioned and give the export meter serial number once it is installed. Payments will be quarterly or monthly depending on the supplier.

6. Understand VAT and grant eligibility

Solar PV panels and their installation attract 0% VAT on UK domestic properties - a change made in 2022 that still applies in 2026. This applies to panels, inverters, batteries installed at the same time, and mounting systems. Make sure any quote you receive reflects 0% VAT on the whole system, not just the panels.

If you are also considering a heat pump, the Boiler Upgrade Scheme (BUS) grant of £7,500 for an air source heat pump is still available in 2026. The grant goes to your installer and reduces the invoice to you. To be eligible, your property needs a valid EPC and must not have an outstanding recommendation for loft insulation or cavity wall insulation on that EPC. Sort the insulation first if needed - it is cheaper than losing the grant.

There is no government grant specifically for solar panels in 2026. The financial case rests on generation savings, SEG income and, if applicable, smart tariff arbitrage via a battery.

When to call us

Richard handles the electrical side of solar and battery storage installations across Sandwich and east Kent: consumer unit upgrades, earthing checks, EV charger connections and anything that needs a qualified electrician alongside the MCS installer. If your installer needs an electrical contractor on the job, or you want an independent check on the electrical proposal, get in touch.