Sociotechnical typologies for national energy transitions

The energy landscape is changing dramatically. It is populated by many different and discrete energy transitions happening simultaneously in across different sectors, with dynamically different drivers, and across varying locations. This Perspective proposes a new three-part categorization to help better understand the myriad socio-technical changes being witnessed, which cut across user and market behaviour as well as institutions and technologies. We express energy transitions in three categories: Interim energy transitions, shaped by policies without necessarily public acceptance, mostly within non-democratic regimes. Deliberate energy transitions, driven by citizen-driven change without supporting policies. Transformative energy transitions stem from a combination of policy and citizen-driven change. The degree of permanence of these three transition types depends on the real and perceived benefits to energy users, sustained adoption of technology, and the regulatory regime. However, what is energy transition and why should we promote it? Energy transitions broadly refer to processes that entails changes from one form, style, state, place or scale of energy system to another (Melosi 2010, Sovacool 2016, Child and Breyer 2017). They are often accompanied by some form of energy system transformation in form, nature, appearance and character (often for the better), occurring at different scales within municipal, sub-national, national and international levels requiring multi-modal analysis at different scales (Geels and Kemp 2006, Child and Breyer 2017, Duan et al 2019). Indeed, social dimensions such as knowledge, motivation, norms, values and other contextual factors also impact the scope, speed, or scale of energy transitions (Steg et al 2015), especially transformative ones that challenge incumbent regimes (Stirling 2019, Kanger et al 2020). Energy transition often entails long term structural changes in energy systems leading to a shift in production and consumption patterns towards low-carbon energy sources (Grubler 2012, Davidsson 2014, Edomah 2019). One of the more established definitions is that energy transitions entail a change in fuels and associated technologies, such as switching from the use of fuel wood to petroleum products or changing from steam engines to internal combustion engines (Hirsh and Jones 2014, Edomah 2020). Others argue that a transition entails a shift in fuels and sources of primary energy supplies (Miller et al 2015), a change in patterns of energy use among energy users in society (O’Connor 2010, O’Connor and Cleveland 2014), or a switch in economic systems ormarkets depending on one form of energy source/technology or another (Pearson 2012). Amajor factor used in defining and ascertaining the sustainability of an energy transition is its temporality. Several related questions arise. How does the pace of change impact on energy transition dynamics? How long is optimal for different types of energy transitions? Defining or at least grappling with the timing and contextual specificity of energy transitions can be difficult (Sovacool 2016). This is because energy transition occurs in different ways and the timing and duration of transition is highly dependent on contextual norms within different energy geographies (Verbong and Geels 2007, Steg et al 2015). Stylized phases, path dependency, lock-in and subversion, which attempt to explain the way with which the principles and values of energy systems in place are contradicted and reversed, may play a vital role in defining the temporality or permanence of energy transitions. Indeed, there has been conflicting evidence with respect to the timing of energy transitions (Sovacool 2016). In challenging some misleading understanding of the concept of energy transition, York and Bells argue that it is important to be able to distinguish between energy transitions and mere energy additions (York and Bell 2019). As evidence to this claim, historical changes in energy systems that happened in the nineteenth and twentieth centuries were based on an


Introduction
The energy landscape is changing dramatically. It is populated by many different and discrete energy transitions happening simultaneously in across different sectors, with dynamically different drivers, and across varying locations. This Perspective proposes a new three-part categorization to help better understand the myriad socio-technical changes being witnessed, which cut across user and market behaviour as well as institutions and technologies. We express energy transitions in three categories: Interim energy transitions, shaped by policies without necessarily public acceptance, mostly within non-democratic regimes. Deliberate energy transitions, driven by citizen-driven change without supporting policies. Transformative energy transitions stem from a combination of policy and citizen-driven change. The degree of permanence of these three transition types depends on the real and perceived benefits to energy users, sustained adoption of technology, and the regulatory regime. However, what is energy transition and why should we promote it?
Energy transitions broadly refer to processes that entails changes from one form, style, state, place or scale of energy system to another (Melosi 2010, Sovacool 2016, Child and Breyer 2017. They are often accompanied by some form of energy system transformation in form, nature, appearance and character (often for the better), occurring at different scales within municipal, sub-national, national and international levels requiring multi-modal analysis at different scales (Geels and Kemp 2006, Child and Breyer 2017, Duan et al 2019. Indeed, social dimensions such as knowledge, motivation, norms, values and other contextual factors also impact the scope, speed, or scale of energy transitions (Steg et al 2015), especially transformative ones that challenge incumbent regimes (Stirling 2019, Kanger et al 2020. Energy transition often entails long term structural changes in energy systems leading to a shift in production and consumption patterns towards low-carbon energy sources (Grubler 2012, Davidsson 2014, Edomah 2019. One of the more established definitions is that energy transitions entail a change in fuels and associated technologies, such as switching from the use of fuel wood to petroleum products or changing from steam engines to internal combustion engines (Hirsh andJones 2014, Edomah 2020). Others argue that a transition entails a shift in fuels and sources of primary energy supplies (Miller et al 2015), a change in patterns of energy use among energy users in society (O'Connor 2010, O'Connor andCleveland 2014), or a switch in economic systems or markets depending on one form of energy source/technology or another (Pearson 2012). A major factor used in defining and ascertaining the sustainability of an energy transition is its temporality. Several related questions arise. How does the pace of change impact on energy transition dynamics? How long is optimal for different types of energy transitions?
Defining or at least grappling with the timing and contextual specificity of energy transitions can be difficult (Sovacool 2016). This is because energy transition occurs in different ways and the timing and duration of transition is highly dependent on contextual norms within different energy geographies (Verbong andGeels 2007, Steg et al 2015). Stylized phases, path dependency, lock-in and subversion, which attempt to explain the way with which the principles and values of energy systems in place are contradicted and reversed, may play a vital role in defining the temporality or permanence of energy transitions. Indeed, there has been conflicting evidence with respect to the timing of energy transitions (Sovacool 2016).
In challenging some misleading understanding of the concept of energy transition, York and Bells argue that it is important to be able to distinguish between energy transitions and mere energy additions (York and Bell 2019). As evidence to this claim, historical changes in energy systems that happened in the nineteenth and twentieth centuries were based on an addition (and increased share) of new energy fuels and technologies in the energy mix (York and Bell 2019). Indeed, this suggests that a transition away from fossil fuels may require much more than growth in renewables.
While several papers have explored the notion of timing (World Economic Forum 2013), temporality (Sovacool 2016) and geographies of energy transitions (Bridge et al 2013), less work has investigated possible types of energy transitions and the forms in which they manifest. Defining or at least proposing a typology of energy transitions enables us to carry out a systematic classification of the various types by their drivers, effects, actors, and spatial implications at the analytical, normative, practical, and policy levels. In this Perspective, we present a framework of three types of energy transitions defined by the degree of willingness of energy consumers to accept (behavioural) change, regulatory/policy backing supporting such changes in energy use patterns, and temporality.

Socio-technical types of energy transitions
We argue that there are three types of energy transitions primarily defined by socio-technical aspects and driven by some combination of policy incentives or citizen-driven change. The three types of energy transition are: • Interim energy transition • Deliberate energy transition • Transformative energy transition Table 1 summarizes the high-level aspects of these transition types, and the sections to come explore them in more detail.

Interim energy transitions
This is a form of energy transition that results from policies without public acceptance in the form of imposed rules and political pressures on energy users. This is common within non-democratic settings. These imposed rules could be intentional or unintentional. It is intentional when the imposed regulations are aimed at achieving a set objective in energy consumption pattern and use. It is unintentional when imposed rules and other forms of political pressures lead to unintended consequences in energy use. This form of energy transition may also occur in a case where there are no imposed regulations. It may result through some form of political pressure and persuasion from friends or pressure groups to adopt a new technology or change energy use behaviour. Some examples of interim energy transition include municipal laws abolishing the use of kerosene lamps for lighting purpose, or laws restricting the use of fuel wood for cooking. This type of energy transition occurred across several geographies during the lockdown period of the 2020 coronavirus (COVID-19) pandemic (Guo et al 2020). Imposed rules in the form of forced lockdown measures resulted in many families being confined to their homes which led to a consequent change in energy use patterns across several sectors. Indeed, the International Energy Agency (IEA), in the 2020 Global Energy Review report on the impact of COVID-19 crisis on global energy demand and CO 2 emissions, argued that energy demand reduced by an average of 25% (in countries with full lockdown) and 18% (in countries with partial lockdown) per week respectively (IEA 2020). The IEA further argued that the decline in energy demand was dependent on the stringency and duration of lockdowns. According to the IEA report (which evaluated energy dynamics in 30 countries), electricity demand reduced by at least 20% in several countries with full lockdown (IEA 2020). The upsurge in residential electricity demand far outweighed the reductions recorded in industrial and commercial sectors. The shift of some professional and educational services to the homes led to a temporary surge in residential energy consumption (Edomah and Ndulue 2020). Many educational institutions switched to online or distance learning mode while some professional services by persons in different organizations shifted to the homes, resulting in some new patterns of working and learning. This resulted to increased heating/cooling requirements for more people spending the greater part of the time in their homes. Consequently, the forced lockdown (imposed rules) led to an interim change in energy consumption patterns and a consequent reduction in carbon emissions in the industrial sector.

Deliberate energy transitions
Deliberate energy transition is driven by citizendriven change without supporting regulations. It occurs when there is an intentional (behavioural) change or adoption of a new technology as a result of some perceived benefits to be derived which are not yet backed by regulations. In this form of energy transition, energy users are prompted to act based on some perceived benefits they may derive. Arguably, their decisions are mainly driven by cost-benefit analysis and rational choice, and not just about the environmental benefits or climate impact that the technological switch or behavioural change provides. Some examples of deliberate energy transition include community renewable energy projects and individual purchase decisions leading to the adoption of hybrid and electric cars (Rezvani et al 2015, Mersky et al 2016, Soltani-Sobh et al 2017. Using the example of the adoption of hybrid and electric cars, it can be observed that widespread adoption is not only a result of policies which provides an option for their use. It is mainly the result of a deliberate decision by end users who have decided to Rezvani et al, in their work on the drivers and barriers against consumer adoption of plug-in electric vehicles (EVs), argues that emotion, symbolic meaning, innovativeness, identity, and pro-environmental attitudes are key drivers of EV adoption (Rezvani et al 2015). Rezvani further argued that positive emotions from driving electric cars, pride and joy, positively influenced its adoption. In the European Union, understanding local conditions and addressing regional variations are specific drivers of hybrid and EV adoption (Coffman et al 2017). Meanwhile, in the United States, the presence of some government incentives and other socio-economic factors has been the main driver of EV adoption (Soltani-Sobh et al 2017). Establishing these benefits could mean that technological switch or behavioural change may have to be observed over time in order to ascertain the real benefits, which could last for several years. This is the main factor that is responsible for a longer timeframe of deliberate energy transition when compared with the interim energy transition.

Transformative energy transitions
Transformative energy transitions are more sustained. They occur as a result of a combination of policy and citizen-driven change. In this case, energy users know and understand the benefits of adopting a certain technology or embracing change in energy consumption patterns. The energy consumers willingly accept (behavioural or technological) change, not only because of the perceived benefits they stand to derive but, above all, because the intentional change and the corresponding benefits are backed by regulations. Some examples of transformative energy transitions include country or regional level decisions to retire coal-fired power plants. Other examples include national renewable energy targets defining the target percentage of renewables in the national energy mix. Figure 1 shows a mapping of the socio-technical types of energy transitions. Using the example of the adoption of solar photovoltaic solutions across many parts of Africa, it is argued that this technology have the potential of providing a quick win in addressing the energy access challenge. The adoption rate has been impacted by the acceptance of this new technology by energy users in the forms of solar home systems, solar minigrids, and solar hybrid power solutions (Oyewo et al 2020). The energy users accept these forms of technologies due to the perceived (and actual) benefits that can be derived from them. The adoption is further entrenched by different multilateral agencies, non-governmental organizations and energy/environmental advocacy groups providing financing facilities for various solar projects. In Nigeria, the possibility of household use of solar solutions for lighting, energising rechargeable appliances, and cooling of houses have been the main driver of solar technology adoption among end users (Barau et al 2020). In Central East Africa, the adoption of the Pay-As-You-Go Solar Home Systems is driven by its disruptive positive impact in ensuring access to clean affordable energy for the poor population (Barrie and Cruickshank 2017). Another factor supporting widespread adoption is government regulations, supporting the use of different forms of solar solutions as a strategy for addressing the challenge of energy access. This multi-faceted approach of wilful behavioural change and new technological adoption, backed by government regulations, can lead to a more sustained energy transition. This is the reason this type of transition can last for several decades.

Implications for the study of energy transitions
The use of three socio-technical types of energy transitions enable us to analytically capture the polycentric roles of individuals, groups (actors), geographical units (municipalities, states, countries, etc.), social interactions (energy behaviour) and material artefacts (energy technologies) as the units of analysis as shown in figure 1. It shows how such transitions involve not only technical dynamics and social acceptance, but important coordination effort among diverse actors that tough upon governance and forms of collaboration (or resistance).

Temporal and spatial dynamics
The proposed typology captures better the temporal and spatial dynamics of energy transitions. It envisions transitions not only as a substitution of fuels or an alteration of energy systems, but also the reconfiguration of scale and patterns of activities (Bridge et al 2013). In terms of spatial dimensions, interim energy transitions occur at the micro (small) scale. At this scale, behavioural and technological change is driven by external pressures from individual, household and municipal interests. Deliberate energy transitions occur at the middle (meso) scale. In this type of transition, technological diffusion is driven by sub-national energy interests and targets. Transformative (or a more sustained) energy transition occurs on a large (macro) scale, mainly at national, regional and international levels. Large scale technological deployment is driven by international agreements and interests of transnational firms and nongovernmental organizations.

Complementarity
Complementarity is another important feature arising from our typology. How do complementary and/or competing technologies impact on the type of energy transition we end up with? Arguably, within some contexts, it is possible that solar and wind are complementary technologies while in other contexts, solar and hydro may be competing against each other. In considering the effect of inter-niche competition in transitions, Lin and Sovacool argue that it is important to understand the socio-technical barriers, benefits and drivers that shape energy technology transition. (Lin and Sovacool 2020) Sander and Hillman argue that technological interaction, which provides a basis for complementarity or competition, is a result of some overlapping value chains and sociotechnical elements. (Sandén and Hillman 2011) These technological interactions, according to Sander and Hillman, could be expressed in forms of: symbiosis (with two technologies positively affecting each other); neutralism (where none is affected by the other); parasitism (where one technology is inhibited while the other benefits); commensalism (one technology is benefits while the other is not affected); and amensalism (one technology is inhibited while the other is not affected). Indeed, with respect to competition, two technologies affect each other negatively. (Sandén andHillman 2011, Lin and

Societal embedding
It is important that we lastly consider the contextual dimensions that can societally embed transitions into daily forms of life. That is, transitions can embed new technologies into business practices or household routines, and such practices and routines can in turn create new demands for energy technologies and needed transitions (Kanger et al 2019). Contextual norms, spatial narratives across different energy geographies, diverse path dependent trajectories, and complementary and competing technologies can all shape people's behaviour and then lead to the mutual shaping back of technology. A failure to recognize and account for the socially embedded factors that are invariably responsible for shaping national energy systems may lead to an under-analysis of the significant social factors that may determine the nature of ongoing and future low-carbon energy transitions (Geels et al 2018). A failure to acknowledge the nationally specific incumbencies that define energy systems may also risk the marginalization of some European countries whose economies are still highly dependent on increasingly taxed carbonintensive forms of energy (Balta-Ozkan et al 2015, Burke and Stephens 2018).

Conclusion
Ultimately, our typology of transitions suggests that these polycentric aspects, their spatial and temporal dynamics, and complementarity of fuels and technologies all shape energy transitions. They shape contextual norms, spatial narratives across different energy geographies, diverse path dependent trajectories, and complementary and competing technologies lead to different pathways that define and shape future energy systems.
In this Perspective, we proposed a three-fold categorization of energy transitions that have both conceptual utility but also policy applicability. There is a need for policymakers to understand how policies without public acceptance can lead to interim energy transition and how citizen-driven change without supporting policies leads to deliberate energy transition. Indeed, policymakers would prefer a combination of policies and citizen-driven change which lead to a more sustained form of energy transition. The three types of energy transitions presented can help policymakers and other energy stakeholders to provide adequate (socio-technical and policy) responses that addresses evolving issues at various points of the energy transition process. It is also believed that the typology proposed can be used to inform future research or policy agendas.

Data availability statement
All data that support the findings of this study are included within the article (and any supplementary information files).

Author contributions
Norbert Edomah conceived the idea and wrote some sections of the Perspective. Morgan Bazilian provided some concrete examples on the different types of energy transition in section 2 and also fine-tuned the conclusion. Benjamin provided some concrete insights on the ideas presented in sections 2 and 3.