As has been identified in previous articles, building occupants’ behaviour has a significant effect on energy consumption. It is often said that “you can’t manage what you can’t measure” and this is very true when it comes to energy consumption. As energy users, we generally have information on our energy consumption on an annual or, ideally, on a monthly basis. However, it is not very often that we have an accurate knowledge of how the energy consumed is distributed between different uses or specific appliances. It is even rarer to know how this energy is translated into monetary value. This applies to both domestic and non-domestic users. Energy monitoring and smart metering can be the solution to this problem.
Energy monitoring and smart metering can often be combined with data storage, analysis and visualisation. The data collected on site is stored so that it can be further analysed. The data analysis might include hourly, monthly and annual energy use information, together with internal and external temperatures and occupancy information. Finally, different systems have various ways of visualising energy use for various categories of users. It can be a very simple colour change indicating high temperature for a dwelling individual occupant, or it can even include complicated charts and graphs, for building energy managers and professionals. These types of systems feed information into the energy management processes of a building; on a much smaller scale, it is used by the domestic building occupants themselves to understand and reduce their energy consumption. Smart metering provides energy managers or individuals with feedback on operating practices, results of energy management projects, and guidance on the level of energy use expected in a certain period.
There are a variety of systems providing different information and levels of detail, for domestic and non-domestic buildings, which come at considerably different costs. The same system, depending on its level of complexity, might provide information not only on energy use, but on a multitude of parameters; it might include weather and indoor environmental conditions, such as internal and external relative humidity and temperature; it may even include information on electricity production, for example, through the use of solar or wind energy.Furthermore, metering might involve measurements on specific intervals, real time energy consumption information, a memory to store consumption patterns and even comparison with average consumption. Finally, most smart metering devices are compatible with PCs and mobiles, providing more flexibility to the users who want to explore and analyse their energy use.
The UK government has decided to roll out the use of smart metering for electricity and gas information, as part of the plan to upgrade the UK’s energy system. The aim is for all homes and small businesses to have smart meters by 2020. Consumers with smart meters will be offered a display informing them on their energy use and its cost in pounds and pence. This will allow them to acquire near real time information and to gain control over their energy use and consequently to save energy and money.
Smart metering is expected to inform and even to motivate people to improve their energy efficiency. In some cases, the use of smart metering itself might be a reason for energy consumption reduction. In other words, the observed energy consumption reduction can be seen as a combined effect of physical energy efficiency measures taken and the installation of energy monitoring.
With energy production as with consumption, it is important to make the whole process as visible as possible. Research shows that most households with solar PVs ‘expect a fair payment for their own-generated electricity and would like to be able to see, separately, the amounts of electricity that they are importing and exporting’. In households where this information is visibly displayed, increased awareness has resulted into a change of behaviours, reducing total electricity consumption by as much as 20% from pre-microgeneration levels.
Overall, UK and international evidence shows that considerable savings are achievable through metering. Cost-benefit analyses in other countries, which have adopted similar energy savings measures, identify 6.4% electricity and 5.1% gas savings, respectively. This is achieved with direct feedback through an in home display. These values drop down to 3.2% and 3.7% respectively for the case of indirect feedback. The value is 3% for electricity savings in Ireland, resulting from the installation of smart meters. Earlier studies in Japan and in the Netherlands had reported savings of approximately 9%. Immediate direct feedback could be extremely valuable, especially for savings from daily behaviour in non-heating end-uses. In the longer term and on a larger scale, informative billing and annual energy reports can promote investment as well as influence behaviours. In general, savings have been shown to range from 5 to 15% and from 0 to 10% for direct and indirect feedback respectively.
Furthermore, social interaction can be valuable for the reduction of domestic energy consumption; advice and comments, personal and household energy consumption data from users can be crucial in informing and motivating other consumers. This can be done both through energy companies and benchmarking, as well through the use of data platforms where users will be able to share their energy use information and ways to decrease it.
Finally, on a larger scale, gathering information on users’ preferences, energy consumption and habits can also be of significant importance, allowing us to target peak times, specific uses and consumer groups. Thus, detailed information can be used, not only by individual energy users and building managers, but also by engineers, policy makers and the government to make more informed decisions. Decisions that will allow us to reduce our environmental footprint without sacrificing comfort.
Image Credit: US Navy via Wikimedia Commons