Study on the feasibility of waste-based biogas for electricity generation in the Irish Grid for a high renewables penetration scenario

This study examines the feasibility of harnessing biogas from waste biomass, to replace natural gas used in fast-acting turbines that manage the intermittency of the Irish Electric Grid, in a high renewables penetration scenario. A simplified model of the complex national grid was developed to mimic the exchange of electricity across the country's largest generation points and consumption centers. The model was validated through Load Flow analysis and this simplification was shown to be representative of the Irish Grid. The waste biomass considered was livestock & poultry waste, along with agricultural residues of the Island of Ireland. These biomass potentials were correlated with the existing grid model to determine the potential available per node. Technologies to convert this waste biomass to biogas were explored and selected based on the compatibility between available feedstock and the required application. Ireland's natural gas grid was also examined and the possibility of upgrading the biogas to biomethane was explored and finally chosen over storing and using native biogas. All parameters were then projected into 2020 and the feasibility of using biogas to cover the island's electricity demand was examined. A cost analysis was performed to verify the feasibility of this proposal and it is deduced that replacing natural gas with homegrown biogas is energetically and technically possible. The study then discusses the sustainability and geopolitical implications of choosing biomethane over natural gas and concludes that with the right financial incentives from the government, a successful transition to a fully renewable system is economically and technically feasible, and would greatly contribute to Ireland's energy independence.