Modeling the Diffusion of Competing Residential Heating Systems
Project duration: 7/2008 - 6/2011
Funded by E.ON ERC
Residential heating accounts for 75% of the total final energy demand for residential purposes in Germany. It is mainly based on oil and gas and, therefore, connected to fluctuating energy prices, security of energy supply and environmental considerations. Against this background, innovative residential heating systems (RHS), such as the gas- or oil-fired condensing boiler with solar thermal support, the heat pump or the wood pellet-fired boiler, have come into the focus of policy makers and private homeowners in the past few years. All of these competing RHS provide the same quality of residential heat; however, they have significant differences in their economic, environmental and technical characteristics. Besides the external decision context, personal-sphere elements, such as attitudes or norms, which are shaped by economic framework conditions, seem to play a role in the adoption decision process in favor of RHS.
In the first step of our research, we developed an integrated theoretical framework for assessing the homeowner’s adoption decision for an innovative RHS (FCN Working Paper No. 2/2010). Starting from an attitude-based theory (Theory of Planned Behavior), we proposed a framework that explicitly accounted for economic aspects and personal-sphere determinants. Based on this framework, we developed and pre-tested a questionnaire for a large mail survey of owners of existing and newly built 1-2 family homes in Germany, who have recently installed a new RHS. The main survey for the case of Germany (sample size: 5000 homeowners) achieved an overall response rate of about 60% (N=2985).
We applied different econometric and multivariate analysis methods in order to investigate the survey data. Based on a multinomial regression model, we analyzed the influence of preferences, socio-demographic characteristics and home and spatial variables on the adoption probability for a certain RHS (FCN Working Paper No. 9/2011). Our findings show that there are different drivers for the adoption of RHS in newly built and existing 1- and 2-family homes, and that the importance of key drivers differs across groups of homeowners and RHS. First, we find that adopters of a gas- and oilfired condensing boiler with solar thermal support have a strong preference for energy savings, while adopters of a heat pump or wood pellet-fired boiler prefer being independent from fossil fuels. Second, we find preferences for RHSspecific ttributes to be highly relevant for owners of newly uilt homes, while evidence on the influence of control ariables is scarce. Third, we find that socio-demographic, home and spatial characteristics have a higher and more differentiated impact in the case of existing homes. These variables predetermine the decision context and leave less leeway for the influence of preferences when replacing an RHS in an existing home.
Results from a principal component analysis show that the motivation of homeowners to adopt an RHS has six dimensions (FCN Working Paper No. 17/2011). They include (i) the associated costs (ii) the general attitude towards the RHS, (iii) the government incentive, (iv) reaction to framework conditions like energy security and environmental issues, (v) the comfort related to the RHS and (vi) the influence of significant others (subjective norms). Moreover, we show that the relevance of the components varies between the adopted RHS and the type of home.
Next steps in this research include data analysis with structural equation models in order to further investigate the individual adoption decision.
Michelsen C.C., Madlener R. (2013). Switching from Fossil Fuel to Renewables in Residential Heating Systems: An Empirical Study of Homeowners' Decisions in Germany, FCN Working Paper No. 14/2013, Institute for Future Energy Consumer Needs and Behavior, RWTH Aachen University, October.
Michelsen, C. C., Madlener, R. (2013). Motivational Factors Influencing the Homeowners' Decisions Between Residential Heating Systems: An Empirical Analysis for Germany, Energy Policy, 57(June): 221-233. [ScienceDirect]
Michelsen, C.C., Madlener, R. (2012). Homeowners' Preferences for Adopting Innovative Residential Heating Systems: A Discrete Choice Analysis for Germany, Energy Economics, 34(5): 1274-1283. [ScienceDirect]
Michelsen C., Madlener R. (2010). Integrated Framework for Assessing the Determinants of Homeowner’s Adoption Decision in Favor of an Innovative Residential Heating System, FCN Working Paper No. 2/2010, Institute for Future Energy Consumer Needs and Behavior, RWTH Aachen University, February.
Sunak, Y., Michelsen, C., Madlener, R. (2009). Descriptive Statistical Analysis of the Diffusion Dynamics of Residential Heating Systems in Selected European Countries. Interim Project Report, Institute for Future Energy Consumer Needs and Behavior, RWTH Aachen University, December.
Michelsen C.C., Madlener R. (2012).Modeling the Diffusion of Competing Residential Heating Systems, E.ON Energy Research Center Series, Vol. 4, Issue 3, June (ISSN: 1868-7415). [Download]
Supervised student research
Schäfer A. (2009). Lead Markets for Innovative Residential Heating Technologies – A Survey and Analysis of Selected Countries in the EU, Study thesis, Chair of Energy Economics and Management, Faculty of Business and Economics, RWTH Aachen University.
von Avenarius A. (2009). Market and Value Chain Analysis of Residential Heating Systems: The case of wood-pellet boilers, electric heat pumps and gas-condensing boilers in Germany, Bachelor thesis, Chair of Energy Economics and Management, Faculty of Business and Economics, RWTH Aachen University, September.