How much do solar panels cost in Northern Ireland?

What a solar system actually costs in 2026

Prices below are fully installed, including scaffolding, mounting, inverter, all electrical work and NIE Networks paperwork. They assume a straightforward pitched tile or slate roof with reasonable access.

What pushes the price up

• Scaffolding complexity — restricted access, three-storey properties or work over a conservatory add cost before a single panel is fitted.
• Roof covering — natural slate takes longer to work than concrete tile, and fragile older slate sometimes needs replacement around the fixing points.
• Consumer unit upgrades — older boards without RCD protection or without a spare way need replacing before the system can be connected.
• G99 applications — anything over 3.68 kW per phase needs NIE Networks approval before connection, adding administration and lead time.
• Multiple roof planes — splitting an array across two or three orientations usually means power optimisers or a second MPPT string.
• Bird protection — mesh skirting is worth adding from the start in areas with gulls or pigeons rather than retrofitting later.

What brings the price down

• Zero-rated VAT until 31 March 2027 on domestic installations, including batteries fitted on their own. From 1 April 2027 the rate reverts to 5%.
• Larger arrays — cost per kWp falls as system size rises, because scaffolding and labour are largely fixed.
• Fitting solar and battery together — you share the scaffolding, the hybrid inverter and one set of electrical works instead of paying twice.
• Street-level batching — where several neighbours install together, scaffolding and mobilisation are shared.

How the payback actually works in Northern Ireland

Two numbers drive the return: what you save by using your own generation, and what you earn by exporting the rest. In Northern Ireland those numbers are far apart. Importing a unit costs about 34p (Power NI's standard domestic credit rate is 34.15p per kWh including VAT from 1 July 2026, so check your own tariff). Power NI pays 11.88p per kWh for exported electricity from 1 October 2026 to 30 September 2027, as of October 2026, and resets the rate each year. Every unit you consume yourself is therefore worth nearly three times as much as one you sell.

That should shape the design. A 4 kWp system generating 3,600 kWh a year is worth about £985 if you consume 70% of it: 2,520 kWh used at 34p is £857, plus 1,080 kWh exported at 11.88p is £128. If you consume 35% it is worth about £706: 1,260 kWh used at 34p is £428, plus 2,340 kWh exported at 11.88p is £278. The panels are identical. The difference is a battery, a hot water diverter and when you run the washing machine.

On that basis, a £5,800 4 kWp install that uses half its output at home earns about £826 a year (1,800 kWh at 34p plus 1,800 kWh at 11.88p) and pays back in roughly seven years, then delivers free generation for another eighteen-plus years of warranted panel life. At 35% self-use it is about eight years (£5,800 ÷ £706). Reaching 70% usually takes a battery, so its cost belongs in the sum: with a £3,000 battery the system costs £8,800 and pays back in about 9 years (£8,800 ÷ £985). With no export payment at all, the half-used system earns about £612 a year and pays back in about 9.5 years. These figures assume the import price stays where it is, and it can move.

Questions to ask any Northern Ireland installer

• Is the generation estimate specific to my roof's pitch, orientation and shading?
• Is the quote inclusive of scaffolding, or is that a provisional sum?
• Who applies to NIE Networks, and is a G98 notification or a G99 application required?
• What commissioning documents will I receive at handover?
• Who registers the panel, inverter and battery warranties, and who do I contact if a manufacturer fails?
• How much deposit is due before installation, and how is it protected?