Further Analysis of Data from the HEUS Consumer Archetypes Further Analysis of Data from the Household Electricity Usage Study: Consumer Archetypes Final report for Department of Energy and Climate Change and Department for the Environment Food and Rural Affairs 29 November 2013 Element Energy Limited 20 Station Road Cambridge CB1 2JD Tel: 01223 852499 Fax: 01223 353475 1 Further Analysis of Data from the HEUS Consumer Archetypes Contents 1 Executive Summary ............................................................................... 4 2 Introduction .......................................................................................... 10 3 Methodology ........................................................................................ 11 3.1 Step 1: Factor Analysis .................................................................... 11 3.2 Step 2: Identifying the Clustering Variables ..................................... 13 3.3 Step 3: Cluster Analysis ................................................................... 15 3.4 Step 4: Interpreting and Profiling the Clusters ................................. 19 4 Profiles of the Household Archetypes .................................................. 20 4.1 Overview of the Household Archetypes ........................................... 21 4.2 Occupant Characteristics ................................................................. 25 4.3 Building Details ................................................................................ 30 4.4 Electricity Usage .............................................................................. 34 4.5 Technical Potential........................................................................... 36 5 Conclusions and Recommendations .................................................... 42 6 Appendix A ........................................................................................... 46 7 Appendix B ........................................................................................... 47 2 Further Analysis of Data from the HEUS Consumer Archetypes Authors For comments or queries please contact: Dr Mark Hughes [email protected] 01223 855240 Jorge Garcia Moreno [email protected] 01223 852490 3 Further Analysis of Data from the HEUS Consumer Archetypes 1 Executive Summary Objective The diversity and variation in electricity consumption between different households across the UK represents a significant barrier to understanding future energy consumption and policy impacts at anything but highly aggregated levels, where most of the detail and fidelity is lost. Sorting these households into several well- resolved and characterised groups makes it possible to explore national electricity usage trends at more disaggregated levels, revealing consumption patterns and policy opportunities for different consumer archetypes. Cluster analysis is a statistical technique that allows households to be grouped on the basis of attributes such as demographics, attitudes and behaviour, where the differences in these attributes are minimised within each group and maximised between groups. The Household Electricity Usage Study conducted by the Department of Energy and Climate Change (DECC), the Department for the Environment Food and Rural Affairs (Defra) and the Energy Saving Trust provides comprehensive data on the electricity usage patterns of 250 owner-occupier households in England between 2010 and 2011. Element Energy’s objective in this project was to perform a comprehensive cluster analysis on the data from the Household Electricity Usage Study to group the 250 monitored households into a series of distinct consumer archetypes based on household attitudes to the environment, demographics, building details and electricity usage characteristics. Approach As part of the Household Electricity Usage Study, participants completed a survey including 29 questions on household attitudes and behaviours in relation to the environment, climate change and energy use. Factor analysis, which identifies the common themes underlying the survey questions, was used to condense the 29 survey questions into 3 factors on climate change and the environment:  Current beliefs  Current actions  Beliefs about the future These 3 factors were then combined with 9 further variables on household demographics, building characteristics and electricity use to complete the full set of clustering variables. These additional 9 variables were:  National Readership Survey (NRS) social grade  Household occupancy (i.e. the number of people living in each house)  Building age  Building floor area  Number of electrical appliances 4 Further Analysis of Data from the HEUS Consumer Archetypes  Total electricity use per annum (excluding space heating1)  Percentage of electricity used in the 6-7pm peak period  Appliance efficiency improvement potential (i.e. the electricity that could be saved by switching to modern energy efficient appliances such as those with classes of A+ or A++ and low standby power)  Peak shift potential (i.e. the amount of electricity use that could feasibly be shifted out of the 6-7pm peak period) Clustering analysis was performed using the software package, SPSS, via a multi- stage procedure involving hierarchical analysis (using Ward’s method) and k-means analysis. The clustering methodology involves an iterative procedure to group the households so that the differences in attributes between groups are maximised and the differences within each group are minimised. The optimal variance between and within clusters was found to occur for a seven cluster solution. The Seven Household Archetypes The distribution of households across the seven household archetypes is shown below in Figure 1 and Table 1 gives a brief description of each of these clusters. 7. Peak-Time 1. Profligate Users [N=24] Potential [N=18] 10% 7% 2. Thrifty 6. Off-Peak Values [N=62] Users [N=47] 25% 19% 3. Lavish Lifestyles [N=23] 9% 5. Practical Considerations 4. Modern [N=50] Living [N=26] 20% 10% Figure 1: The relative size of each of the seven clusters produced for all households (N=250) in the Household Electricity Usage Study. A more detailed profile of the specific characteristics of each group is provided in Table 2. This table includes the twelve variables used for the cluster analysis, and an 1 Electricity use for space heating was not included in the total since many households were monitored outside of the November to March period in which space heating would typically be used. 5 Further Analysis of Data from the HEUS Consumer Archetypes additional variable describing the potential savings from switching heating fuel (or to a more efficient electric heating system) in each of the clusters. This additional variable could not be included in the clustering variables used for the cluster analysis because not all households were monitored in the November to March period in which space heating is generally used. Table 1: Summary of the seven household archetypes. 1. Profligate Potential (7%) – these are high occupancy, low social grade households with the highest levels of electricity consumption and large numbers of inefficient appliances. While their beliefs may be relatively green, they are failing to put these into action and exhibit, by far, the greatest scope for appliance efficiency improvement. 2. Thrifty Values (25%) – this cluster consists of small, relatively low social grade households with few appliances and low levels of electricity use. Conservative electricity consumption is accompanied by non-green attitudes, indicating that the frugal focus of these households derives from cost-conscious values rather than environmental conservation. 3. Lavish Lifestyles (9%) – these are affluent households with the highest social grades and largest building floor areas. While they possess green beliefs, this is not reflected in their actions which are characterised by high electricity use and many appliances. 4. Modern Living (10%) – the small, predominately single occupant households in this cluster live in newly built homes and have medium to high social grades. These households use low levels of electricity which is well-aligned with their green actions and small household sizes. 5. Practical Considerations (20%) – these medium to high social grade households have the highest occupancy levels, yet still manage to constrain their total electricity usage to medium levels. These households have the lowest electricity use per person, reflecting the judicious use of electricity in densely occupied (i.e. lowest floor area per occupant) households with relatively green beliefs. 6. Off-Peak Users (19%) – these medium social grade households consume a small fraction of their total electricity use during the peak-time period. These households possess predominately retired respondents, which is linked to their off-peak electricity usage patterns. 7. Peak-Time Users (10%) – this cluster exhibits high levels of electricity use with a high fraction of this occurring during the peak-time period. These households have, by far, the highest peak shifting and fuel switching potential savings available, though their relatively non-green actions appear to be inhibiting the extent to which these are currently being realised. 6 Further Analysis of Data from the HEUS Consumer Archetypes Table 2: Characterising the seven household clusters. All quantities shown in brackets reflect the average value for the cluster. 1. Profligate 2. Thrifty 3. Lavish 4. Modern 5. Practical 6. Off-Peak 7. Peak-Time Potential Values Lifestyles Living Considerations Users Users Current beliefs Very Green Not Green Very Green Moderately Green Very Green Not Green Moderately Green (z-score)2 (0.36) (-0.68) (0.56) (0.16) (0.79) (-0.35) (-0.19) s Current actions Moderately Green Moderately Green Not Green Very Green Moderately Green Very Green Not Green tn cits (z-score)2 (0.01) (0.11) (-1.25) (0.65) (0.00) (0.22) (-0.22) ap ire Beliefs about the future Moderately Green Very Green Moderately Green Not Green Very Green Not Green Moderately Green uc tc (z-score)2 (0.07) (0.43) (0.18) (-0.41) (0.27) (-0.66) (-0.15) c a O ra Social grade Low Low High High-Medium High-Medium Medium Medium h C (average NRS grade) (C2) (C2) (B) (B-C1) (B-C1) (C1) (C1) Household occupancy High Low High Low High Medium Medium (average no. of people) (3.4) (1.7) (3.3) (1.2) (3.6) (1.9) (3.0) Building age Older Older Medium Newer Older Medium Medium gnid slia (average age band) (1930-1949) (1930-1949) (1967-1975) (1983-1990) (1930-1949) (1950-1966) (1967-1975) liuB teD B(auvieldriangge f lmoo2)r area M(1e1d2i)u m S(7m8)a ll L(1a6rg9e) S(7m7)a ll M(1e0d7i)u m M(1e1d1i)u m M(9e7d) ium Electrical appliances Many Few Many Few Medium Medium Medium (average no. of devices) (53) (27) (53) (31) (43) (48) (47) y ticir ega T(koWtahl /eyleeacrt)r icity use V(7e8r3y9 H) igh L(2o2w5 4 ) H(5i5g6h7 ) L(1o8w6 8 ) M(4e0d8i4u)m M(3e4d9i1u)m H(5i8g7h1 ) tc s e U Percentage of electricity lE Low Medium High Medium Medium Low High used in the 6-7pm peak (5.6) (6.3) (6.9) (5.8) (6.2) (5.5) (7.1) (%) Efficiency potential Very High Low High Low Medium Medium High la la (kWh/year) (1546) (344) (719) (323) (652) (516) (791) cin itn Peak shift potential Medium Low High Low Medium Low Very High h e (kWh/year) (31) (11) (36) (8) (24) (14) (124) ceT toP Fuel switch potential Medium Low High Very Low Low Medium Very High (kWh/year) (483) (243) (530) (62) (321) (425) (1,049) 2 The three factors are presented as z-scores (i.e. standardised scores) which indicate the number of standard deviations each household response differed from the mean response (which has a z-score of 0). 7 Further Analysis of Data from the HEUS Consumer Archetypes Conclusions and Recommendations The unique characteristics of each of the seven household clusters (as defined by the demographic, behavioural and building characteristics in Table 2) make it possible to identify where different interventions could be best focused. We have examined the technical potentials (i.e. the maximum potential saving that could be achieved in each household archetype) for interventions relating to energy efficiency, peak shifting and heating fuel switching or optimisation. It should be noted that the technical potentials do not provide an indication of the likelihood of household change (which is linked more to other considerations such as lifestyle drivers), only the extent of the savings that are technically possible.  Profligate Potential households offer by far the greatest technical potential for appliance efficiency savings with an average opportunity of 1546 kWh/year per household (about double that of any other cluster) or approximately 2.9 TWh/year nationally. When considered alongside the very green current beliefs of Profligate Potential households, there appears to be scope for uptake of appropriately targeted interventions. It is recommended that this household archetype be targeted for awareness raising and other policy interventions relating to energy efficiency.  The medium levels of appliance efficiency savings potential per household (652 kWh/year) of the Practical Considerations cluster, when combined with their strong representation in the UK population (20%), yields a large potential for efficiency savings at the national level (3.4 TWh/year). Practical Considerations households also have very green current beliefs that may favourably predispose them towards appliance efficiency interventions. As such, this cluster should be considered a high priority group, alongside the Profligate Potential cluster, for energy efficiency interventions.  The Peak-Time Users cluster offers, by far, the highest technical potential for shifting electricity use out of the evening peak demand period with a per household average capacity of 341 W during the 6-7pm peak (more than triple the next highest cluster) which equates to approximately 0.9 GW nationally. The Peak-Time Users cluster also offers the highest electricity savings for switching heating fuel (or to a more efficient electric heating system) – on average 1049 kWh/year per household and about 2.7 TWh/year nationally. However, these high technical potentials are combined with non-green current actions and only moderately green beliefs in this cluster indicating there may be limited willingness or motivation to address these areas at present. It is recommended that further work be conducted to investigate the drivers and incentives that could motivate households in the Peak-Time Users cluster to 8 Further Analysis of Data from the HEUS Consumer Archetypes realise the high technical potentials of this household archetype, particularly in the context of future demand-side response strategies.  The Lavish Lifestyles cluster also offers high heating fuel switching potential per household (530 kWh/year, which scales to about 1.3 TWh/year for the UK), the majority of which (82%), was from secondary electric space heating devices supporting a non-electric central heating system (i.e. natural gas or heating oil). This indicates significant potential for electricity savings by optimising use of the primary central heating system in this cluster (approximately 1.1 TWh/year across the UK) and it is recommended that awareness raising and other interventions in this area be targeted at this cluster. Such interventions will need to consider the lifestyle priorities (related to high social grades) that motivate this group and currently appear to hinder the adoption of environmentally friendly behaviours in this cluster.  Finally, the well-defined clusters produced in this project offer excellent scope in future work for combining the household clusters with other low-carbon technology uptake and geographical mapping studies3,4,5. We recommend that future household studies examining low-carbon technology uptake, demand- side response strategies and policy impacts are structured so that they can be linked to the Household Electricity Usage Study clusters identified in this project, thereby revealing potential synergies with implications for policy development and grid management. 3 Element Energy (2011) “Plug-in Vehicles Economics and Infrastructure: Quantifying Consumer Behaviour”, for the Energy Technologies Institute. 4 Element Energy (2009), “Strategies for the uptake of electric vehicles and associated infrastructure implications”, for the Committee on Climate Change. 5 Element Energy (2009), “Uptake of energy efficiency in buildings”, for the Committee on Climate Change. 9 Further Analysis of Data from the HEUS Consumer Archetypes 2 Introduction The diversity and variation in electricity consumption between different households across the UK represents a significant barrier to understanding future energy consumption and policy impacts at anything but highly aggregated levels, where most of the detail and fidelity is lost. Sorting these households into several well-resolved and characterised groups makes it possible to explore national electricity usage trends at more disaggregated levels, revealing consumption patterns and policy opportunities for different consumer archetypes. At this level, the drivers and implications of consumption trends can be better understood, facilitating new insights into electricity usage and offering expanded opportunities to target policies and energy strategies that represent the needs of population sub-groups as well as the UK as a whole. Cluster analysis is a statistical technique that allows households to be grouped on the basis of attributes such as demographics, attitudes and behaviour, where the differences in these attributes are minimised within each group and maximised between groups. This technique makes it possible to define categories of consumer archetypes based on multiple household characteristics, extending the scope of analysis beyond the limitations imposed by exploring each of these household metrics in isolation. The Household Electricity Usage Study conducted by the Department of Energy and Climate Change (DECC), the Department for the Environment Food and Rural Affairs (Defra) and the Energy Saving Trust provides comprehensive data on the electricity usage patterns of 250 owner-occupier households in England between 2010 and 2011. Element Energy’s objective in this project was to perform a comprehensive cluster analysis on the data from the Household Electricity Usage Study to group the 250 monitored households into a series of distinct consumer archetypes based on household attitudes to the environment, demographics, building details and electricity usage characteristics. To accurately identify consumer archetypes within national electricity consumption, it is necessary to gather comprehensive data across a range of individual households that are representative of the entire population. Between 2010 and 2011, the Department of Energy and Climate Change (DECC), the Department for the Environment Food and Rural Affairs (Defra) and the Energy Saving Trust carried out a comprehensive study into the electricity usage behaviour of 250 owner-occupier households in England. Over the course of this investigation, referred to as the Household Electricity Usage Study, a large dataset was assembled characterising the appliance 10