Sectoral coupling pathway towards a 100% renewable energy system for Northern Ireland

Northern Ireland, in alignment with the United Kingdom's net zero targets for 2050, is focusing on a transition to a 100 % renewable energy system. Wind energy is the backbone of this future system due to its abundant resource potential, low environmental impact, and cost-effectiveness. However, achieving a fully variable renewable energy system requires flexibility on the demand side to reliably facilitate the displacement of traditional dispatchable power plants with variable renewable resources such as wind and solar. To address this challenge, this study aims to develop optimal pathways for transitioning Northern Ireland's current energy system to 100 % renewable energy. The proposed model outlines eight pathway steps that reflect technical and operational changes needed on both the supply and demand sides. These steps include: 1) building a reference model, 2) implementing a district heating system, 3) deploying electric heat pumps, 4) reducing reliance on dispatchable power plants, 5) integrating electric vehicles, 6) incorporating demand-side management, 7) producing methanol for buses and trucks, and 8) replacing remaining fossil fuels with synthetic gas. Each step is evaluated using EnergyPLAN, which considers both technical and economic viability alongside the increased penetration of wind and solar power. The findings illustrate that Northern Ireland can transition to a 100 % renewable energy system at a cost comparable to its current system, providing a practical and cost-effective pathway to meet its 2050 target. By analysing the impact of each step individually, this study provides valuable insights for policymakers on effectively decarbonising Northern Ireland's entire energy system.