Targeted and Tangential Effects—A Novel Framework for Energy Research and Practitioners

Abstract

Interdisciplinary energy research that focuses on the upcoming energy transition is growing at pace and scale given the goal of the Paris Agreement to limit global warming to 1.5 °C. As a consequence, integrated interventions are needed to support the energy transition. However, gaps in the energy literature remain on how to manage uncertainties inherent in energy transition. Based on a review that showcases some of the shortcomings in the current literature, this paper introduces a novel framework to provide a structure on how to engage with uncertainty called targeted and tangential effects. Relevant case studies in residential energy and energy justice as well as household retrofits and health are used to demonstrate how the targeted and tangential framework can be used. The targeted and tangential effect concept provides an innovative framework for energy researchers and practitioners to use to proactively recognize and identify uncertainty in the energy transition. Benefits and shortcomings of this framework are presented. Areas of future research are identified, including relevance for policy.

1. Introduction

Previous energy transitions have shown that energy system transformations or fuel switching depend on a variety of factors, including policy, price, and availability, and research has shown that those changes have been neither linear nor smooth [1]. With increased focus on the importance of climate change and the need to limit global warming to 1.5 °C, there has been a proliferation of research on how to manage and facilitate the upcoming energy transition [2,3,4,5]. Demand-side and supply-side changes are required and they will need to occur in an integrated manner to minimize disruptions [6,7,8].

There has been an increasing amount of attention on interdisciplinary and integrative-type research in the energy system [9,10,11,12,13,14]. Examples of this include nexus-type research—including but not limited to water energy nexus [15], waste to energy nexus [16], and the food, water, energy nexus [17]. They also include decision-type frameworks, such as the energy trilemma [18]. Nevertheless, gaps in the energy literature remain on how to manage uncertainties in the energy sector. The main research question is: how can uncertainties be managed and to what extent can they be proactively identified?

The purpose of this paper is to introduce a novel framework that aims to address this question by reviewing the relevant energy sector literature and validating the importance of addressing the gap. As such, the rest of the paper is as follows: (a) the relevant literature in the energy sector will be reviewed, (b) a novel framework that introduces targeted effects and tangential effects will be presented alongside relevant case studies to address this, and (c) this will be followed by a discussion and conclusion, including areas of future research.

2. Literature Review on Uncertainties in the Energy Sector

The energy system is inherently subject to a variety of uncertainties—this includes the short-term aspects—such as real-time, hourly, and daily fluctuations—and long-term considerations—such as planning and policy priorities or technologies that are not yet fully developed [19,20]. A variety of examples dealing with uncertainty have been explored in the energy literature—including technical aspects—such as the integration of intermittent renewables into the energy system and price fluctuations based on consumer demand [21]—and social aspects—such as understanding individual perspectives around energy use and how they interact with the energy system [22].

Due to the uncertain nature of the energy sector, unintended outcomes are recognized [23,24,25].

Table 1. Examples of Unintended Consequences in the Energy Sector.

Topic	Intervention	Unintended Outcomes	Sources
Travel	Improve fuel efficiency of vehicle	Travel further due to lower cost of travel and fuel efficiency improvements	[26]
Housing/Buildings	Energy retrofit to improve energy efficiency	Higher indoor pollutants and mold presence if not ventilated correctly	[27]
Renewables	Generous subsidies to encourage uptake of solar PV	Large PV installations may result in excess electricity consumption and not generation	[28]
Social Justice	Electric vehicles can help accelerate the low-carbon energy transition	Cost of an electric vehicle and charging infrastructure may exclude rural and low-income communities	[29]
Agriculture	Fertilizer subsidy program aimed to encourage growth of specific crops	Greater concentration of specific crops and non-food crops leads to lower food security and diversity	[30]

provides an overview of how some of these have been categorized across various sectors in the energy field, showcasing some of the insights across various sectors.

As Table 1 illustrates, unintended outcomes may occur due to a certain policy intervention. Improving energy efficiency in buildings can lead to higher levels of mold and indoor pollutants if the ventilation is not properly integrated [27]. Large PV installations may result in excess electricity consumption [28]. The question then becomes—can these unintended outcomes be proactively identified and managed?

The framing of these unintended outcomes has been developed in the literature in various forms.

Table 2. Framing of Unintended Outcomes in the Energy Sector.

Framing	Overview	Example	Source	Further References
Spillover	When an intervention aimed at one behaviour ‘spills over’ and impacts other behaviours that were not targeted	Campaign aimed to encourage recycling behaviour then leads to water recycling or electricity conservation	[31,32]	[33,34]
Rebound Effect	When an intervention aimed at decreasing energy use or increasing efficiency ‘rebounds’ and results in an unintended increase in energy use	Improving the efficiency of a car and then travelling more frequently due to lower cost	[35]	[36,37]
Nexus Research	By taking a multi-sector approach, nexus research evaluates interactions among different topics	Food–water–energy nexus can provide greater insights than when looking at each topic in isolation	[38]	[39,40]
Decision Frameworks	Frameworks aiming to explore uncertainty in the energy space	Examples include the Energy Trilemma or Framework of Unintended Consequences	[41,42]	[43,44]

illustrates an overview of these.

As Table 2 highlights, and building on a previous literature review by the author [45], there is a body of literature that recognizes the consequences of unintended effects. The spillover effect illustrates how an impact on one behaviour may also have an impact on other behaviours. The rebound effect conveys that actions in energy efficiency may be counterproductive. This body of literature examines how one intervention may impact other interventions or be counterproductive.

However, it is important to recognize that this literature primarily examines whether or not a spillover or rebound effect occurs—but does not provide a framework on how it can be proactively identified, categorized, and/or managed. Where frameworks have been developed, there is a call to apply them to policymakers and look across sectors. Truelove et al. developed an integrative framework of pro-environmental spillover and highlighted the importance of future research to be policy-relevant and look across behaviours [46]. Vivanco et al. had similar findings for the rebound effect—stating that future research should look across direct and indirect impacts and broaden its scope to look across different sectors to further policy support [47].

Nexus research is one such example of how examining multiple sectors simultaneously can help generate insights that would not occur if examining one sector in isolation. This includes understanding linkages and tradeoffs across sectors that may not be understood if looking only in isolation—which can lead to better decision making and understanding [48]. Nevertheless, gaps can still exist in nexus-type research, including the need to better manage integrative research in the energy sector as well as focusing on the importance of continuously improving the integrative research in a way that is practical and pragmatic [49]. The relevance that this has for energy transitions continues to grow in importance [50,51,52].

Decision frameworks do take a more proactive approach. The energy trilemma looks at how security of supply, energy access, sustainability can be managed in the energy sector [53]. Using a country case study, Setyowati highlights which tradeoffs exist across these pillars at a national level—including regulatory environment certainty, policy reform to support finance mobilization, and unlocking rural renewable electricity financing [54].

The Framework of Unintended Consequences yields similar benefits. Using two case studies (planetary boundaries framework and water–energy–food nexus), the framework provides five recommendations on how it can be used, including broad and encompassing assessments, iteration, pragmatism, consensus building, and a learning mindset. It also recognizes that not all unintended consequences can be identified and that changes to the tools and methods being currently applied need to change or be updated [41].

With the progress in this field in mind and for context, it is important to recognize that further work can be done to identify and manage unintended consequences proactively and tools can be developed to adapt to ever-evolving circumstances in an uncertain field such as the energy sector. The literature in supply chain management has showcased the importance of proactively identifying unintended consequences [55]. Research across different energy sectors has recognized the importance of identifying unintended consequences [2,25,56] and demonstrates the need to continue to develop tools that can help identify them.

Given the gaps identified and building on the literature review, it is clear that further tools can be developed in this space to further advance the integrative energy research agenda. As such, the aim of this paper is to introduce an innovative framing to some of these issues which has been developed—building on the author’s previous research and findings [57]. The objective of this paper is to provide a framework that can be operational to energy researchers and practitioners. This is presented in the next section.

3. Introducing Targeted and Tangential Effects

The word tangent comes from the Latin term tangentem—meaning to touch [58]. In geometry, it is used to highlight a point that touches a curve at only one point. This is highlighted in Figure 1 below.

Building on this, this section introduces a novel framework for the first time—called the targeted effect and the tangential effect.

The targeted effect is on a certain focus area—this could be on household electricity use, energy imports, or a specific sector—when there is a designed, intentional intervention on a defined area. Examples include an electricity display intervention in the home, feedback on travel behaviour through an interactive application, or community awareness campaign on recycling. There are then areas that are not relevant or related to the intervention—these are areas that are out of scope and do not have any relevance to the intervention at play.

There is then something in between—which are described as tangential effects—which occur due to the designed intervention but are not the focus of the intervention. The tangential effect can be described as any set of energy-related phenomena that occur outside of the targeted intervention of interest that is likely to be linked, occur, or touched from the intervention as outlined in Figure 2. Figure 2 has three stages—pre-intervention, the intervention, and post-intervention.

A new framing is warranted because it can provide many benefits currently lacking in the literature when dealing with uncertainty. First, the term targeted highlights a specific or identified area. The word tangential has also been chosen because not only does the effect stem from the targeted intervention, but it also can move in any direction (positive impact, negative impact, or both).

Additionally, there is a difference between tangential effects and untargeted/unintended effects, spillover, or rebound effects. These impacts may not be as unexpected or unpredictable as the literature review suggested, and therefore a term that highlighted this continuous effect in its many different forms was sought. Unintended or untargeted may be a suitable term to use when exploring whether or not an effect would occur, but another term was sought that would distinguish itself from the current literature by recognizing that these effects are likely to happen in certain circumstances. Therefore, the introduction of the term tangential was used as it relates to an intervention but then impacts another secondary energy scope in a direction that was not part of the targeted intervention.

It is important to rehearse how the term tangential effect is different from spillover. As illustrated earlier, this research has shown that untargeted effects do occur and may not be as accidental or unpredictable as the word spillover suggests. Therefore, a distinction from the spillover terminology is warranted. Equally, this research distinguishes itself from that body of literature by providing a framework that is able to focus on how and why changes do/do not occur and how they might be managed—thus introducing the tangential effect.

Secondly, targeted and tangential effects can be used to highlight how little is known about energy interventions across a wide set of sectors. As the literature review has shown, research that examines multiple sectors simultaneously is able to generate richer insights than when looking at one in insolation. Therefore, this framework can be used to not only examine the energy sector, but can also be used as a tool to recognize how and where future research can be focused moving forward.

Thirdly, it is important to note the framing and the figure can be utilized in a variety of arenas. Exploring the targeted and tangential effects of various policy interventions, whether residential, transport, industrial, or a combination can be explored.

In order to help illustrate the use of this framework, earlier in the paper (Table 1), five examples were used to provide context on untargeted effects. Here, two case studies based on existing literature are introduced to showcase how the framework can be used. The first examines residential energy and social justice and the second examines household energy and residential health. These will then be followed by a discussion and conclusion that highlights how this can be utilized alongside relevant areas of future research.

3.1. Case Study—Gas to Biomass Switch Leads to Tangential Effect in Energy Injustice

Using Axon and Morrissey’s research as an example, here we highlight how tangential effects could be utilized and reframed in the context of residential energy and energy injustice [59]. The focus of the research was to examine how a biomass energy system, focusing on low-carbon energy transition in a low-income community, was intended to facilitate progress for the local economy and the environment. However, given the associated changes from a prepayment meter to a pay-as-you-go meter alongside the energy switch, this led to a payment injustice where residents in the low-income community faced increased costs and energy inequity, counter to the intended impact. Figure 3, using the targeted and tangential framework, is shown below.

The authors highlighted that these impacts can be avoided by examining the needs of the community more thoroughly, including the impact of the pricing structure intervention on the residents, as well as having a pilot phase for the payment system in order for it to be designed to be support the objectives of the intervention [59].

Using the targeted and tangential framework, the intention of using this framing as a tangential effect and not a spillover effect, rebound effect, or unintended consequence is that it can inform and support future interventions by framing the insights from past interventions in this manner. As a consequence, this framework can be used to illustrate that these impacts are not accidental or unexpected and facilitate future interventions in a more proactive manner. It also has the potential to empower the researcher and practitioner to recognize and identify areas where tangential impacts could occur based on previous research and inform future policy packages and interventions more effectively and synergistically.

3.2. Case Study—Home Retrofits and Tangential Effects in Health

Using Petsou et al.’s research as an example, there has been a tremendous focus on energy retrofits as part of a broader framework to help achieve a low-carbon economy-wide transition [60]. However, if done in isolation and not in an integrated manner, retrofits can lead to tangential effects, including mold growth, respiratory infections, and excessive humidity. As such, targeted and tangential effects can be highlighted in Figure 4.

Given the history in the field of the sick building syndrome [61], tangential effects in energy retrofits can be highlighted to showcase where integration can take place and where synergies should occur—including aligning cost, carbon, and comfort.

Using the targeted and tangential framework, this framework can be used to illustrate the interlinkage between home retrofit, improved insulation and energy efficiency, humidity, mold, and infections. Looking back, it provides a tool for the researcher to ascertain linkages across these themes and moving forward, it can empower the researcher and practitioner to proactively recognize and identify areas where tangential impacts could occur and inform future policy packages and interventions more effectively and synergistically. An example of how this can be applied in forthcoming research is highlighted in the next section.

4. Discussion—How Can the Targeted and Tangential Effect Framework Be Used?

Building on the gaps highlighted earlier and in order to optimize the use of the framework, the following questions can be used to identify tangential effects. They are not all-encompassing but are intended to be used as a guide to help operationalize the framework. Guided questions are listed in

Table 3. Supporting questions for the targeted and tangential effect framework.

Guided Questions to Identify Tangential Effects
Which areas are within the scope of the targeted intervention?
What opportunities exist to integrate this intervention alongside others?
What areas exist across the supply chain of the intervention?
What can previous interventions teach us about future interventions?
What could this intervention look like in the future?
What would happen if this intervention did not take place?
What tangential effects could occur if the targeted intervention did not go to plan?
How can the intervention be different from previous interventions?
Where are tangential effects likely to occur? And where are they unlikely to occur?
Where could there be blind spots in the intervention?
Where have previous interventions not examined and why?
Where can we identify partners for the intervention in order to better understand the context?
How could this intervention be made more equitable?
How could this intervention avoid inequalities?
How can the short-term impacts of the intervention be monitored?
How can the long-term impacts of the intervention be monitored?
When is the best time for the intervention and why?
When would the intervention be appropriate?
When could the targeted and tangential effects be monitored?

.

The intention of these questions is not necessarily new or pioneering—but used alongside the tangential framework, they have the potential to proactively identify areas that may not have been identified before through the recognition of the tangential effect. Figure 5 provides an overarching framework that can be used.

The proposed framework can help in understanding energy-related impacts and provide a tool to examine their relevance. Additionally, it is important to highlight that tangential effects are intended to be used as a tool to promote interdisciplinary, cross-sectoral, action-based research and/or policymaking in order to identify tradeoffs and devise policy packages that reinforce one another and not counter each other. The hope is that this framework can assist foreseeing potential linkages and synergize efforts. The above case studies have been used at the intersection of energy and energy justice as well as energy and health, but can be applied to a variety of other sectors and arenas—including transport, food, energy policy, and others (or a combination).

As an example, a future energy researcher/practitioner needs to examine the best way to integrate a transport-related intervention on a community. By exploring previous similar interventions, a list of the possible tangential effects can be identified. Additionally, based on the questions provided above, additional potential tangential effects can be identified. This includes opportunities to streamline other interventions—or identifying risks that could impede tangential effects. Where tradeoffs exist, this framework can also be used to highlight decisions, articulate any possible impacts, and minimize or fully understand any disruptions.

Furthermore, this framework provides the practitioner with a toolkit to recognize that interventions are multifaceted and not linear—and can have multiple impacts across sectors and areas of interest. This multidimensional framework can then help further devise research agendas or policy priorities that are fit for purpose and functional.

With that being noted, and as highlighted earlier in the paper, the ability to predict future impacts is inherently uncertain and will always change and evolve [41]. As a consequence, the intention of this framework is to be continually used and revised to take in the latest directions and forecasts—but also to be adaptable and flexible to evolve as the sector evolves. Given the increased role of technology, artificial intelligence, and automation, new challenges, opportunities, and risks exist that may not have been experienced before. However, the intention is that the targeted and tangential framework can be used to assist energy researchers and practitioners in evaluating these outcomes—or evolve with the sector as the demands/needs change.

It is important to recognize that this framework does not come without limitations. First, in certain circumstances, tradeoffs will exist where multiple tangential effects may take place. This is recognized and the intention of the framework is not to avoid tradeoffs, but where they do exist, to highlight where multiple tangential effects exist and make an informed decision on what the costs/benefits are where relevant [62].

Secondly, targeted and tangential frameworks are not static and they may evolve over time. At present, the framework highlights a simplified and straightforward process (pre-intervention, intervention, and post-intervention) and in reality, some of the tangential effects may vary over time and space in each of the stages. This limitation is recognized and the intention is to use the framework in a way that recognizes this—meaning that multiple effects can occur and interact/evolve over time.

Finally, the two case studies utilized above highlighted negative tangential effects—but it is worth noting that some tangential effects may also be positive. This includes tangential effects that support the targeted intervention.

5. Conclusions

The upcoming energy transition distinguishes itself from previous transitions as it will not only be techno-economically driven but also socio-politically driven. As such, interventions are more probable and unintended consequences in an uncertain domain are more and more likely to occur. Building on the current literature, the targeted and tangential effect framework was introduced as a tool to help address these uncertainties.

Case studies were utilized based on previous research to show how the tool can be used based on existing literature. Additionally, the framework can be used for upcoming research or decision making in order to highlight some of the intricacies or interdependencies—or explore how they may exist. This is a tool that can be used to assist qualitative research, policy questions, technical energy modelling/detailed data where tangential effects may exist, or a combination.

There are a multitude of arenas where this framework would be applicable. This includes sector-specific intricacies—including industry, transport, agriculture, residential, buildings, or a combination. This can be applied to supply-side or demand-side interventions, or both. An example includes how an electric vehicle subsidy leads to greater uptake of EVs but may have an unintended consequence on home electricity use. More importantly, the research framework can help link areas of academic research that have not yet been connected—but through the framework are able to generate further insights through integration and recognition of targeted and tangential effects. This includes links across energy sources, uses, and sectors.

The contribution of this framework is that it distinguishes itself from other frameworks by proactively recognizing that tangential effects may occur—and instead of asking whether or not they will occur—it proactively seeks and identifies how to best manage them or understand tradeoffs that exist among options.

The hope is that this addresses a current gap in the literature as highlighted earlier. Additionally, the relevance for practitioners is to use this tool to address multifaceted energy dilemmas by proactively identify any synergies or tradeoffs, or provide additional relevant context for decision points.

The intention is for this tool to be used across the energy sector to help ensure that the upcoming energy transition is designed and equipped for multilateral interventions that are acceptable, affordable, and just for all.