Rooftop PV has potential to meet 185% of electricity demand in Northern Ireland

University of Ulster analysis finds installing solar on half of Northern Ireland’s would generate 13.5 TWh per year, however significant gaps between PV generation and demand remain. Government commissioned report recommends introducing new incentives to support rooftop solar.

Installing PV on 50% of Northern Ireland rooftops would cover 185% of annual electricity demand, according to an Ulster University report commissioned by the Northern Ireland Executive’s Department for the Economy.

The authors found installing PV on half of Northern Ireland’s roofs would generate around 13.5 TWh of electricity per year, but with significant misalignment between generation and demand.

Despite a mismatch in supply and demand, particularly between November and January, the analysis found that adding PV would result in cost savings in all scenarios modeled.

Households in Northern Ireland with PV systems installed currently meet around 28% of their electricity demand through solar, according to the researchers, who added that the economic and environmental benefits depend on exporting electricity to the grid.

Residential PV deployment has been muted, however, with solar installed on just 3.4% of residences in Northern Ireland according to the analysis. The latest solar deployment statistics from the UK government show 84 MW of PV capacity for installations up to 4 kW in Northern Ireland as of April 2025, 22% of the 377 MW total capacity.

The authors of the paper recommended policymakers consider introducing a financial incentive scheme for domestic PV installations as those offered in other parts of the United Kingdom.

The UK government has incentivized PV for households in England, Scotland and Wales through the Energy Compliance Obligation 4 (ECO 4) scheme, and other support mechanisms have been introduced by the devolved governments in Scotland and Wales. Equivalent support has not been offered by the Northern Ireland Executive. Ireland also supports solar, the report noted, leaving Northern Ireland “as an outlier” locally.

Other recommendations made include streamlining the G99/NI process by which domestic PV installations with a capacity greater than 3.68 kW are assessed, changing building regulations to require solar PV on all new buildings, and encouraging consumers to install “solar plus” technologies such as battery energy storage and PV hot water diverters, in a bid to allow more PV per household without increasing electricity exports to the grid.

Researchers assessed the PV potential of Northern Ireland with a model incorporating 1.4 million buildings with a total rooftop area of 169 million m². Dwellings accounted for 787,000 buildings in the analysis with the rest made up of industrial, commercial and other non-domestic properties.