The deployment of renewable energy technologies in the home, such as heat pump systems, is increasingly encouraged in many countries to curb climate change and dependence on fossil fuels. However, the adoption process is not well-understood. In this paper, we develop an agent-based model to analyze the uptake of heat pump systems over time and the underlying diffusion factors. Specifically, we model the influence of three key factors: economic, psychological, and social networks, on the adoption levels of heat pump systems in existing Irish homes until 2030. Uniquely, we use recent nationally representative Irish household survey data and historical heat pump uptake data to derive parameters for decision rules based on empirical data. Our baseline scenario predicts that approximately 260,000 Irish households will install a heat pump at their home until 2030, although the number varies across different features of heat pumps and could reach up to 550,000. We test the sensitivity of the uptake levels to changes in upfront costs, grant amounts, future prices of electricity and other fuels, and analyze their implications for energy demand, cost savings, and reduction in CO 2 emissions. We also discuss how individual household socio-demographic characteristics, building characteristics, geographical location of household, and policy incentives influence the adoption process. This research should be of interest to policymakers, as we use the model to test the impact of commonly implemented policies on technology adoption rates and show that policy instruments addressing upfront costs have the most impact
