If the UK is to address its energy reduction targets, it is vital to understand energy use behaviours and to devise technology that positively encourages domestic occupants to use less energy. This study is cross-over research that spans energy research, social science and socio-technology. The work presented in this dissertation reveals the domestic energy saving potential of the use of In-hone Displays (IHDs) by quantifying changes in actual energy consumption and then evaluating these changes using social science research techniques to document the psychological nature of the human interaction with a digital user interface (UI).
Many studies have investigated how IHDs for domestic electricity use change behaviour; the findings of this unique 37 month pre-normative study, the first of its kind in the UK, show that the coloured dual-fuel IHD had a positive effect on consumption behaviour and energy reduction. However, the exact difference in energy consumption between experimental groups is dependent on the type of normalisation condition applied to the recorded energy consumption.
After the first six months of monitoring, those with a coloured IHD reduced their gas consumption by an average of 20% compared to a control group; this was tested to be statistically significant (p.05), the interviews found that those with an IHD did not directly attribute their reduced use of electricity to the IHD. Rather, they maintained low levels of electricity use because it was an ingrained habit long before they used the IHD and for fire and safety reasons.
Between the 6 month report and 31 month report, both experimental groups reduced the amount of electricity and gas they consumed. This was attributed to changes in weather patterns and occupants growing more accustomed to their new home. The properties with highest gas consumption reduced their consumption closer to that predicted by the Standard Assessment Procedure (SAP). The research found contrasting differences in how the two utilities where perceived and used. This was evident when the energy data was divided into groups based on occupancy. Larger savings in gas consumption was seen in the intervention group with lower occupancy: the intervention group consumed considerable more electricity than the control group in the lower occupancy dwellings, and consumed considerably less in the larger occupancy dwellings. Electricity was described as a luxury, used to maintain a certain quality of life. Those with younger dependents felt it necessary to provide them with as much electronic luxury as they could. Electricity was relatively freely accessed and used by all residents with little resistance if a justified reason was given for its use. However, space heating was perceived as a sacrificial commodity. Heat was described as being relatively easy to regulate with the use of blankets and extra clothing. Heating controls were perceived to be out of reach for many but one or two in the household. This tended to be in control of the person responsible for the majority of household tasks.
The users of Ewgeco IHD commented more on the device’s ability to promote new gas saving behaviour in order to reduce gas consumption. In contrast, the visual representation of real-time electricity consumption was used more as a safety feature, and appears to fail to produce significant electricity reduction. The participants used the electricity consumption information to reinforce their existing levels of electricity use awareness and it highlighted electrical appliances that had been left on to them. This was reported to be specifically useful at times when the occupants were retiring from the living spaces in the home.
These findings demonstrate that a simple ‘push-information’ style IHD may need to evolve further with greater smart home control functionality, internet capability and user interaction for this technology to be part of the low-carbon solution. However, it has also been demonstrated that, for particular household groups, IHDs can lead to longer term changes in energy consumption behaviour, specifically for heat.