How can energy-relevant investment decisions be boosted? The role of events as initiators and drivers of the decision process

Households can make fundamental contributions to reaching carbon reduction targets by means of high-impact energy-relevant investments. Using a stage model of decision-making, we analyzed which external factors, i.e., strong and disruptive events, make households consider such investments and may push their decision process forward. Three investment types were investigated: renewable heating systems, energy-efficient insulation measures and electric vehicle (EV) purchases. N = 812 German homeowners, living in existing single- or two-family houses, were questioned. As expected, a great majority of the participants could be allocated to the early stages of decision-making, i.e., they either do not consider an investment at all or they are still unsure whether to do so. Thus, we focused on these early stages in the following part of our analysis, employing several ordinal logit regression (OLR) analyses. The analyses revealed that the investments in renewable heating systems and energy-efficient insulation measures are related to economic, ecological, and social events. The importance of specific events for the decision-making process differed, though, depending on the type of investment and the point of decision-making investigated. The propensity to invest in an EV was influenced mainly by the necessity to buy a new car, while ecological and economical events played a relevant role, too. The findings provide insights for the design of intervention strategies that empower households to make energy-relevant investments, thereby not only considering the type of investment, but also the stage of decision-making households are in.