An analysis of fuel heating costs by University College Cork's Paul Deane shows heat pumps to be the cheapest means to heat your home in ROI.
Based on ROI energy data from the Sustainable Energy Agency of Ireland the graph below shows how much a unit of useful heat costs to warm your home in Ireland, with peat costing the most and heat pumps the least.
Source: Paul Deane UCC, costs include VAT and data is from April 2017. Associated CO2 emissions for higher and lower efficiency levels shown with black markers
The graph compares heating costs on a common base per useful unit of heat output to a room in cent per kilowatt hour for high and low efficiency equipment (boilers, stoves, heaters, etc).