This paper discusses the average energy savings of various smart devices in connection with their average price. By calculating the devices' payback times, a ranking of the tools can be given. The whole study focuses on the average household within the EU-28 in terms of climate as well as in terms of user behaviour. The purpose of the research was to provide a win-win situation for users' wallets and the environment by showing the device which suits both players best. As a result of the research, it was found that the greatest reduction in energy consumption can be reached by an interaction of the smart device and the inhabitants of a smart home. By giving users feedback on their energy consumption through smart meters, average savings of 7.5% are reached. As a smart meter is available for about € 80, it has a payback time of only 4.24 months.conveniently control home electronics and appliances including audio/video, home office, telecommunications, intercom, security, lighting, HVAC, and lawn sprinklers. Control systems can also provide information -residents can find out how much electricity they've used on specific appliances or systems, and utilities can read meters remotely. The systems can be accessed from remote locations by phone or computer, allowing residents to turn on the heat, for example, on their way home from work." The definition of smart homes by Harper and Aldrich [6] has lost nothing of its actuality. The single devices were developed a lot further and now suit their tasks better, but the overall concept has not changed:"A "smart home" can be defined as a residence equipped with computing and information technology which anticipates and responds to the needs of the occupants, working to promote their comfort, convenience, security and entertainment through the management of technology within the home and connections to the world beyond."
Energy saving potentialsA lot of research has been done on the topic of smart homes in general and on its ability to save energy. As presented by Harper and Aldrich [6] the idea of smart homes has a relatively long history. The process of home automation started in about 1915. The introduction of the term "smart" into homes was conducted in the nineties of the last century. According to Louis' paper from 2015 [7], the general energy saving potential of smart systems in Finland is a reduction of 14% of the total energy consumption. He further claims the payback time for smart meters to be 3.5 months. Nevertheless, only little studies can be found which calculate average saving potentials. Most of the studies and whitepapers focus on maximum values. However, a sufficient amount of studies and whitepapers can be found that give an average value of savings in order to calculate the payback times of the various devices. The Nest White Paper published in 2015 [8] gives explicit average savings concerning the smart thermostat and so does for example the study conducted in 2011 by Williams et al. for lighting control systems [9]. Summing up, the field of smart home de...