Three forms of energy prosumer engagement and their impact on time-shifting electricity consumption

Focusing on households’ micro-generation, in this case solar photovoltaic (PV) systems, and the role as prosumers, this paper identifies three distinctive forms of engagement as energy prosumer. These forms are based on responses to statements on being prosumer, and refer to becoming (1) more environmentally conscious, (2) focused on own financial gain, and (3) less concerned about electricity consumption. By applying an ordered logistic regression, we investigate how these different types of engagement influence the self-stated tendency to time-shift electricity consumption according to peak loads in the energy system and to own electricity production. We find that prosumers, who state that being prosumer make them more environmentally conscious, are more likely to time-shift electricity consumption according to peak demands in electricity grid as well as to own production. Prosumers, who express focus on own financial gain, seems more likely to time-shift according to own production, whereas prosumers, who state that they have become less concerned with own consumption, tend to time-shift less according to own production. Furthermore, the results show that the accounting scheme (‘hourly or immediate accounting’ or ‘annual accounting’) has a strong impact on the tendency to time-shift. As could be expected, prosumers with hourly or immediate accounting, are much more likely to time-shift energy consumption to own production compared to prosumers with annual accounting. This paper contributes with new knowledge on the extent to which having PVs, and being an energy prosumer, change and reconfigure the everyday practices of households. The findings suggest that how people see themselves as prosumers and engage in energy-consuming activities have an impact on the tendency to time-shift everyday electricity practices. Moreover, the results also problematize that the present available accounting scheme encourage prosumers to adjust everyday practices to own production, whereas from a system perspective, it would be more sustainable to adjust to the peak loads of the electricity grid. Introduction In a future energy system based on fluctuating renewable energy production such as wind and solar photovoltaic (PV), it becomes increasingly important that energy consumption is adjusted to the fluctuating patterns of production. One strategy to achieve this is to raise the energy awareness of the consumers by transforming them into engaged and active prosumers; A term that was originally coined by Alvin Toffler in the 1980s (Toffler, 1980), and refers to overcoming the general separation of consumption and production in the modern capitalist society. The term has, however, in recent years been introduced specifically within the energy agenda, as a termed used to describe consumers who produce energy themselves through micro-generations technologies, e.g. solar PV panels. Studies show that being involved in energy production influences everyday life and that households with micro-generations technologies change their patterns of energy consumption. For example, a UK study by Keirstead (2007) indicates that PV systems encourage households to reduce their overall electricity 1-102-19 HANSEN ET AL 40 ECEEE 2019 SUMMER STUDY 1. THE DYNAMICS OF LIMITING (ENERGY) CONSUMPTION consumption and time-shift to when generation peaks. Reid and Ellsworth-Krebs (2017) find that solar PV panels give households a sense of satisfaction by being involved in production of electricity or shifting electricity-consuming practices. Similarly, Christensen et al. (2017a) find high commitment to time-shifting electricity consumption among households that have installed solar panels. Together, these studies suggest that micro-generation technologies engage households in energysaving activities and somehow encourage households to change patterns of consumption. Using the case of automated meter reading, Löfström (2014) also illustrates how a new technology in itself, rather than feedback and economic incentives, may lead to increased awareness and interest in energy consumption among the occupants, who thereby maybe become a more active and flexible part of the energy system. However, households might engage as prosumers and become active in different ways, which might relate to their tendency to time-shift energy consumption practices. Theories of practices argue that shared, yet differentiated, engagement in practices can explain the processes and nature of consumption (Warde, 2005), and that technologies such as PVs can influence the engagement in practice and hence potentially reconfigure practices (Gram-Hanssen, 2010). In this paper, we, therefore, investigate the impact of different forms of engagement as prosumers on time-shifting of electricity consumption practices. Based on a representative survey of Danish households with solar PV panels, we use factor analysis to identify three forms of engagement as prosumer, and investigate the correlation with self-reported tendency to time-shift electricity consumption according to own production and to peak demands in the electricity grid. We control for impacts of solar panels characteristics (e.g. accounting scheme and size of the solar panel), general environmental concern, personal and household characteristics (e.g. gender of respondent, income, family composition), and house characteristics (e.g. building year, housing type) that presumably also relate to the tendency to time-shift electricity practices. Individualistic approaches to energy consumption behaviour focusing on individual consumer choices have been criticized from a practice theoretical approach for not paying attention to the social and material configuration of human conduct (Shove, 2010; Southerton, 2013). Hence, instead of focusing on motivating the individual to make better choices by given the right information and economic incentives, practice theoretical accounts, in domains like energy consumption, argue for transforming collective everyday practices in order to achieve more sustainable consumption patterns (e.g. Shove, 2003). Most practice theoretical scholars suggest that practices are held together by recognisable and intelligible elements, denoted as some kind of combination of material objects, shared understandings and meanings or engagement (Gram-Hanssen, 2011, 2010; Shove et al., 2012; Warde, 2005). Where the individualistic approaches focus on stronger economic incentives and better information as a mean to change consumption patterns, the practice theoretical perspective points at technological innovations and cultural processes. For example, new technologies may reconfigure practices and thereby also energy consumption patterns (Gram-Hanssen, 2010), and Warde (2005) introduces processes like social differentiation as a change mechanism in which groups of people engage in the same practices in different ways. Inspired by practice theoretical accounts, this article study how a micro-generation technology (in this case PV systems) can create different forms of engagement in energy consumption practices, which might influence the likelihood of time-shifting these practices. The paper continues with presenting the data, variables and methods applied in the paper, which is followed by a presentation of the results, and finally the results are discussed. Data, variables and methods DATA The analysis is based on a representative web survey among Danish households who have installed solar PV panels. The survey was conducted during the fall of 2018 and carried out by Statistics Denmark on behalf Aalborg University. 4,567 prosumers were selected out of a population of 72,900 Danish prosumers. 54.9 % responded, which gave 2,505 responses, but due to missing data on some questions, the number of observations in the models is 2,121 and 2,154. The survey data were combined with data from the Danish administrative registers and data from Energinet.dk. The survey focused on the everyday life of people living in households with PV systems. DEPENDENT VARIABLES In the survey, we asked the prosumers to what extent they timeshift their electricity consumption on hourly basis to the production of their own PV system, for example by time-shifting to daytime, and to the electricity peak demand, for example by time-shifting to night time. Table 1 shows that a little more than one fourth of the prosumers responded that they do not adjust consumption to own production, whereas almost half responded that they do not adjust to peak demands in the electricity grid. Moreover, half of the prosumers stated that they adjust to own PV production to some or large extent, and very few did this for adjustment to peak demands (16.7 %). Although the percentage of prosumers that state that they ‘not at all’ are time-shifting their electricity consumption seems high, the results indicate that prosumers are somewhat likely to adjust their electricity consumption, primarily to own production, but also to some extent to peak demands in the electricity grid. These two variables are used as dependent variables in the analysis. However, we need to remove the ‘Do not know’ responses in order to transform them into ordinal variables that we are able to model using ordered logistic regression model. Such a model use a non-observable ‘latent’ variable y* as indication of the responses to the ordinal variable, and thereby estimate the correlation between the dependent variable and independent variables (Wooldridge, 2010, p. 504). Thus, we use an ordered logistic regression to model the likelihood of time-shifting electricity consumption, and the coefficients can then be interpreted as in a binary logistic regression, for example using odds ratios. FACTOR ANALYSIS AND EXPLANATORY VARIABLES The explanatory variables is three forms of prosumer engagement. In order to identify these different forms of engagement, we apply a factor analysis with obligue promax rotation