Comprehensive energy solution planning (CESP) framework: an evidence-based approach for sustainable energy access projects in developing countries

Access to affordable, reliable, and modern energy remains a critical goal under the Agenda 2030 for Sustainable Development, especially in remote areas of developing countries. Based on traditional engineering approaches, many energy solution planning tools have been developed to identify the optimal solution in these areas to assess the competition across different technological options. Nevertheless, these approaches, based on an economic optimum, do not necessarily grant long-term sustainability of the solution in specific local contexts, since they are not able to capture the social implications within the Energy-Development nexus. Moreover, also in light of the 2030 Agenda, scientific and grey literature on energy access highlights how energy solutions planning methodologies developed in the last decades need to be complemented by a more comprehensive view, able to integrate evidence from various disciplines, especially engineering and social sciences. Based on the above considerations, this paper introduces a novel framework under the name of CESP, where three social sciences-based phases complement three engineering phases, each one characterized by specific tools, to offer an informed decision framework for the local planner. CESP encompasses a set of techno-economic and socio-technical actions to prevent potential failure as evidenced by a counterfactual analysis used to identify the reasons behind past project failures. The CESP framework presents a sequential and iterative structure that underlines the cyclic perspective of a holistic decision process where social sciences feed the engineering analysis and vice versa. Finally, CESP emerges as a practical and applicable framework for supporting energy access planning in critical areas.


Introduction
In the 2030 Agenda for Sustainable Development, Goal 7 aims to 'ensure access to affordable, reliable, sustainable and modern energy for all' by 2030 [1].
However, according to the International Energy Agency (IEA)'s World Energy Outlook 2022 [2], 770 million people worldwide still live without access to electricity, and more than 2.5 billion lack access to clean cooking.The figures suggest that energy poverty will persist beyond 2030 [3].The lowest growth rates for energy access are registered in SSA, where almost 500 million and 1 billion people still lack both electricity and clean cooking services [4].Lack of access to energy hinders the transition towards productive uses of energy and the local development of modern societies in which economic development is sustained by energy services [5].Energy access is not solely about the availability of energy resources; instead, it involves providing adequate energy services with attributes such as quality, reliability, and affordability [6].
Technologies for granting and upscaling access to energy constitute already a mature market [7,8], with solutions being promoted and deployed by governments, private players, and international organizations [9].Several energy solution planning approaches have been developed for the uptake and deployment of these technologies to support the least-cost optimal choice based on traditional engineering-oriented methodologies.Nevertheless, these approaches have been criticized for not necessarily leading to long-term sustainability in the specific local context [10,11] due to their inability to capture the socio-economic causalities of the energydevelopment nexus [12] beyond the technical and economic dimensions [13].Recent literature discusses how the just energy transition planning in DCs needs to account for social nuances [14], spacing from community consultation and involvement [13] to social acceptance [15], and behavioral dynamics [16,17].
Both in the scientific and grey literature, as well as deriving from field experience, many scholars and practitioners have advocated for a new standard for energy access planning, encompassing a robust connection with social aspects and implications.This standard needs to account for the most recent advancements in affordable and sustainable technological solutions, with a neutral approach that evaluates the competition across different solutions based on their final impact on the economic, social, and environmental dimensions of the specific community [18].Indeed, these three dimensions are strictly interconnected when the sustainability of off-grid energy solutions is claimed [19].Integrated approaches between social and natural sciences must consider the relation between human and natural environments [20], supporting the project from conceptualization to planning, implementation, and impact evaluation.
Based on the above considerations, the paper introduces a structured novel framework named Comprehensive Energy Solution Planning (CESP).It complements a set of traditional engineering-oriented actions (representing the current standard for energy solution planning) with social sciences-based actions, which allow to embed holistic aspects in the project planning.In line with the literature, CESP presents an iterative structure that underlines the cyclic perspective of the two disciplines: the social analysis feeds the engineering analysis, which, as a feedback loop, provides back to the former a set of quantitative information.
The remainder of the work is structured as follows.Section 2 outlines the methodology, explaining the rationale behind the combined research method used in this study.In section 3, the results of the interdisciplinary literature review are shown.The state-of-the-art energy solution planning framework is presented, summarizing findings from technoeconomic literature and leading to some technoeconomic actions.Then, it shows the results of the counterfactual analysis that lead to key socio-technical actions, identifying and coding common reasons for the failure of energy access projects.Section 4 introduces CESP as the outcome of the work, organizing the techno-economic and socio-technical actions into phases, sorting them in a planning logic, and characterizing the actions performed in each phase through an interdisciplinary and practice-oriented literature review.Finally, section 5 contains the conclusions, discussing possible improvements to the proposed framework and recognizing the limitations of the work.

Methodology
The methodology adopted in this work, shown in figure 1, builds upon an interdisciplinary literature review, that is used to feed a combined approach between an engineering-based methodology, the energy solution planning, and a social sciences-based approach, the counterfactual analysis.
In the context of our study, this term refers to 'a comparison between what actually happened and what would have happened in the absence of the intervention' (e.g.Kremer et al [21], WB [22]).Similar approaches can be found in energy research literature.For instance, Sovacool et al [23] selected and studied ten case studies of energy access projects in the Asia-Pacific, analyzing the determinant factors for success.Ikejemba et al [24,25] specifically focused on the failure of renewable energy projects in SSA and provided recommendations for future projects.An empirical quantitative analysis of the factors determining the success of mini-grid projects has also been provided in 2020 by Duran and Sahinyazan [26], who collected information in an open-access database.More recently, Perros et al [27] worked to push forward the notion of productive failure in energy and development research, both through a literature review oriented to the Global South and informal interviews.Building upon such an approach, we enclose the consideration of 'failure as salient as success' as defined by Turnheim & Sovacool [28] and Sovacool [29].
More in detail, the interdisciplinary literature review is performed on three different sets of literature: • The first set analyzed, feeding energy solution planning, concerns techno-economic background knowledge that this paper only aims to distill, basing on previous meta-analyses.These are collected from existing standards proposed by international organizations and in the scientific literature.The state-of-art energy solution planning results from this set of literature, providing some must-have techno-economic actions derived from the engineering practice.• The second set of literature, feeding the counterfactual analysis, derives from two sources; * scientific literature of counterfactual cases collected through a systematic and replicable review; * case studies of failure taken from grey literature of on-field experiences of rural electrification programs.
• The counterfactual analysis is used to understand the reasons for the failure in energy projects by identifying some must-have actions to prevent the failure of energy access interventions in DCs.The analysis is built on counterfactual cases found in scientific and grey literature through a systematic and replicable literature review.Based on the missing actions derived, a list of social-oriented actions originates from the paper, representing its foreground knowledge.
Finally, the CESP originates as an evidence-based output, aggregating the must-have actions derived from the energy solution planning and counterfactual analysis methodologies in phases.The research methodology adopted provides inputs to CESP as a new energy planning framework aimed to support comprehensive strategies for energy access planning (i.e.able to complement the traditional engineeringbased energy solutions planning tools with relevant inputs from social sciences' approaches).

Energy solution planning
This section consolidates some techno-economic elements that form the state-of-art energy solution planning approach.The reviewed technicaloriented methodologies are widely acknowledged and recognized as best practices in energy engineering.Therefore, the derived actions are considered background knowledge for the scope of this work.
Existing standards for the management and planning of energy access projects can be found in recent grey and scientific literature.International organizations majorly contributed to the definition of energy access frameworks.For instance, in 2008 a report by (the ESMAP of the WB) evidenced the lack of an approach for fostering productive uses of energy within electrification projects and advanced a possible systematic and pragmatic solution [11].Moreover, the ADB published in 2015 a sustainable energy access planning framework [30].The elements included in the framework are: energy poverty assessment, demand assessment, resource assessment, costbenefit assessment, sustainability assessment, and affordability assessment.
From the scientific literature, Bengo and Arena [31] provided cases of successful integration of the social dimension, within different BMs for providing energy access.Electricity supply per-se is, indeed, not sufficient for generating effective social impact local business, requiring the adoption of holistic approaches beyond the technical design [32].A needs-driven and participative planning, as claimed by Herington et al [13], is essential to improve the social sustainability of a specific intervention: community needs to be engaged [33] and decisionmaking power need to be spread across multiple groups (polycentricity, as reported by Sovacool [29]).This approach helps both to understand the needs of the beneficiaries and to foster recognition between stakeholders [34].Similar considerations have been made by Akyniele et al [35], who introduced a sustainable planning framework for mini grid development in West Africa, suggesting qualitative must-have actions under multiple dimensions.
The pioneering work by Kumar et al [10] proposed a first standard decision support tool for the planning and formulation of off-grid electrification projects, introducing a three-stage procedure: project development/planning and pre-installation; detailed designing, installation and commissioning; and post-commissioning, including capacity building and monitoring and evaluation.From a systematic literature review, in 2012 Schillebeeckx et al [36] proposed a user-centric toolkit for solution and BM design.More recently, Bacchetti [37] presented a design-based approach applying sustainable productservice systems to the commercialization of distributed renewable energy solutions by small-medium enterprises in low-income contexts, providing tools and actions across the different dimensions of sustainability.Gambino et al [38] developed and tested a methodology for energy need assessment to provide reliable input data for mini-grid sizing.The methodology mentions site selection, energy resource assessment, energy need assessment, BM design, demand forecast, and sizing as crucial actions for the design of an off-grid mini-grid.A similar on-field contribution comes from Barbieri [39], who applied a holistic framework for the deployment of the SET4Food (sustainable energy technologies for food security) project for energy access in humanitarian settings.More recently, Matthey-Junod et al [18] expanded the notion of sustainable energy interventions in displacement settings, proposing an integrated framework for their planning also in terms of BM and tariff design.
As main result, deriving from the above literature and reports, the state-of-the-art of energy access project planning is recognized to encompass a defined set of actions, confirmed in the engineering practice.These are: • Resource assessment: this action involves a thorough assessment of the local energy resources available in the project area.This evaluation enables project planners to understand the potential energy sources at their disposal, such as solar, wind, hydro, or biomass.• Demand assessment: an evaluation of the current energy demand in the community is conducted while considering its future evolution through estimation or modeling techniques.• Technical solution identification: based on the outcomes of the resource and demand assessment, this action identifies the most suitable technical solution (e.g.: solar-hybrid mini-grid, solar-home system, etc.), • Technical sizing: this action sizes the identified technical solution, aiming at its cost-optimality.• Business model identification: once the technical solution is set, a suitable BM to ensure the financial sustainability of the project is identified.• Business model formulation: within this action, the financial strategy for energy service provision is established and the tariff is set.

Counterfactual analysis
This section aims to distill from scientific literature the common reasons that caused energy interventions to fail.The reasons are linked to some musthave actions that were not included in the traditional energy solution planning approach.The literature will be here systematically analyzed, providing the original contribution of the work.
A first set of scientific papers is systematically extracted from the Scopus database with the following research query in the TITLE-ABS-KEY fields: -('case study' OR 'project' OR 'programme' OR 'country' OR 'local case'): limits the research to real-life projects or context-specific cases of study -W/20 ('failure' OR 'failed' OR 'failures' OR 'inaccuracy' OR 'error' OR 'errors' OR 'follow-up' OR 'lesson learnt' OR 'learning from'): this piece of string allows to search for cases of failure linked with the specific context -AND ('energy-use' OR 'mini-grid' OR 'mini grid' OR 'micro-grid' OR 'micro grid' OR 'electrification' OR 'hybrid mini grid' OR 'hybrid mini-grid' OR 'small scale renewable energy system' OR 'solar mini-grid' OR 'local energy system' OR 'off-grid energy system' OR 'off-grid system' OR 'household energy transition' OR 'local energy transition'): this more generic piece of string limits the research to meaningful cases of electrification, whether with generic off-grid solutions or mini grids or for the residential sector perspective.
The screening process was conducted in three steps i.An initial set of 369 papers was obtained through the research query.To refine the selection, papers were considered when meeting the following criteria: publication in the English language, publication date between 2000 and 2022, and A review of grey literature has complemented the set of 25 papers from the systematic review.The grey literature has been sourced directly from the WB's Projects & Operations database (two end-ofproject reports [40,41]) and WB's Open Knowledge Repository (WB-OKR, with two book chapters, namely [42,43], and one technical report [44]).By doing this, the scientific backbone of the work benefits from experiences of real rural electrification programs.The final shortlist of 30 publications has been studied in detail, following the process in figure 2.
The case studies, summarized as a supplementary material to this work, have been processed according to the workflow depicted in figure 2. After an indepth analysis, the key reasons for failure reported in each case study are identified; then, the counterfactual is formulated turning the key reasons for failure into positive key reasons for success; then, coded into must-have actions.Two examples of the application of the process follow: -the case study in Dutt and MacGill [45]  Table 1 depicts the result of this process on each of the 30 key studies.The first column highlights the musthave actions that should have been taken into consideration to ensure the success of the intervention.Overall, the counterfactual analysis, as main result, suggested a total of four socio-technical actions: • Regulatory framework assessment: the regulatory boundaries for the intervention are identified to understand which technical solutions and BMs can take place legally in the context.It is noteworthy that: (i) the four newly identified socio-technical actions are directly derived from the counterfactual analysis, and (ii) the already identified techno-economic actions are also confirmed to be relevant in the context of the counterfactual analysis.This confirms that successful energy access planning strategies need to encompass both techno-economic and socio-technical actions, that are deeply intertwined in the practice [18].

CESP
In line with a project planning and management logic and wording used in international standards such as the Logical Framework Approach [69] or the decision-making theory [70], the must-have actions listed in the previous section are sorted in sequential and iterative phases.The phases are created by connecting some similar actions and temporally sorting, according to the two dimensions of the analysis: techno-economic and socio-technical phases, as depicted in figure 3.
The proposed list of phases is as follows: (1) Context analysis, analyzing the context of the action in terms of regulatory framework and local energy needs; (2) Resource and Demand Assessment, grouping available resource and energy demand assessments; (3) Technical solution design, supporting the identification and the sizing of adequate technical solutions; (4) Business model design, aiming to identify and formulate a consistent BM; (5) Complementary activities: introducing complementary activities to support the success of the intervention; (6) Impact analysis: providing the evaluation of the impact produced feeding it back to Context analysis to reevaluate the targeted local energy needs based on the impact achieved and ensure the effectiveness of the whole project.
The next sub-sections are used to consolidate each of the six phases as a part of the CESP, providing stateof-art tools and strategies to perform each action, taking references from various disciplines.This narrative literature review is presented in practical terms for each phase and action of CESP, to better detail the actions to be performed.

CESP1-context analysis
In the initial stage of the CESP, two actions focused on context analysis need to be performed.The first action aims at assessing the regulatory framework and local rules, a critical component of project design [71].The second action identifies the needs of the beneficiaries and determines the priorities for the project to maximize policy [72] and project [73] outcomes.

Regulatory framework assessment
The lack of understanding of the specific regulatory framework can hinder the successful implementation of any energy access projects in DCs [74].Typically, there are three types of regulations in these countries [42]: technical (establishing standards for grid connections), procedural (authorization processes, bidding mechanisms), and economic (direct subsidies, cross-subsidies).Economic regulation's significance lies in incentivizing lastmile electrification, enabling communities to afford connection fees [75], and attracting private sector investment [44,45].Although an all-encompassing database of electrification regulatory frameworks and incentives in DCs is lacking, two reports are suggested to the energy planner in this action: 2018 International Renewable Energy Agency (IRENA)'s report [76] which offers insightful case studies, and ESMAP's Regulatory Indicators for Sustainable Energy (RISE) initiative which evaluates policy and regulatory support for access to clean cooking, energy efficiency, and renewable energy [77].These tools can provide first indications to the project planner on the local regulatory framework.

Needs and priorities identification
Energy is not an end in itself but may be considered as an instrumental right, a necessary yet not sufficient condition, supporting access to additional services and enabling development.Therefore, energy needs must first be understood from this perspective and then measured and targeted according to a proper metric, able to go beyond a binary approach to energy access.For instance, in the last decade, the GTF [78] has already introduced tiered measurements, considering attributes of energy access like maximum load (kW), energy quantity (kWh), affordability, and reliability.However, more recently, Pachauri and Rao [79] have challenged the MTF approach, suggesting it overlooks energy service diversity and practical value, thus confirming the relevance of measuring relative service gaps rather than achieved attributes [80].
Going further, a possible normative approach to unveil the use of energy for human development purposes is the capability approach (CA) [81][82][83]: this theory is founded on the functionings (doings and beings) and capabilities (opportunities for realizing the functionings) of the individual.CA advocates the realization of the spaces of freedom (i.e. the capabilities) to engage or not in a certain functioning: promoting capabilities instead of functionings enables an individual's freedom and self-determination.In the context of energy access, CA has been already adopted by various authors for different scopes [84][85][86][87] and to already underpin a new rationale for energy interventions, applied for on-field priority assessment by Wang et al [88].
As previously discussed, given the challenges faced in rural areas, energy access needs to leverage local income generating activities (also known as productive uses of energy) which can have the winwin effect to benefit from the energy services while contributing to pay back its investment (via tariff payment) [31].Given the variety of needs that can span from domestic uses to productive activities, different approaches and tools may be developed for this specific phase, and different theories come to hand [89].At any rate, two factors play a crucial role: -The stakeholder's analysis which can employ different tools such as stakeholder matrixes or power-interest diagrams, as suggested by sectorial literature [90]; -The problem analysis, which is necessary to highlight cause-effect relationships to properly identify and then formulate the main activities of the intervention.Theorists [91] have observed that causal representations improve how evidence is sought and utilized when alternative hypotheses are evaluated.
Both the above factors are for instance well included in the Logical Framework approach to project management [69]

CESP2-resource and demand assessment
The second phase of CESP delves into technical data to tailor the intervention to the local context as described in CESP1.The phase comprises two actions: assessing the local availability of energy resources and the local energy demand.

Resource assessment
Small scale, off grid system as referred to in [92] offers the opportunity to better exploit local renewable energy.Precise deployment and sizing first necessitate local resource evaluation.Direct assessments, such as solar irradiation and wind speed measurements, require significant resources.Indirect methods, like web-based tools, offer reliable data for solar and wind availability [93,94].Tools like the Global Solar1 and Wind Atlas2 by the WB, photovoltaic geographical information system (PVGIS) 3by the European Commission Joint Research Centre and Renewables.Ninja4 provide information on various available renewable energy sources for specific locations.Notably, Korkovelos et al [95] released a geographic information system (GIS) layer mapping small hydropower potential in Africa.The derived availability of resources, at the desired temporal resolution, informs supply strategy and technological solution sizing.

Demand assessment
The assessment of the current energy usage is a starting point to quantify the local energy demand and associate it with the need expressed in the previous phase of the CESP.The on-field assessment entails detailed data collection.Visual tools such as Sankey diagrams can help to depict the assessment, clustering users by energy carriers and revealing key energy requirements.
Shifting from current energy needs to estimate future load demand is crucial to allow long-term project's success.This demand analysis covers diverse energy services and time resolutions, balancing data availability and precision.Formulating load curves aids system modeling [96] and aligns it with the local need and the resource assessment already completed, facilitating the upcoming phase of the sizing for the technical solution.
In general, two families of approaches for estimating current energy demand exist [97], including its long term evolution [98]: -Top-down approaches: these set hypothetical power and energy tiers for user categories, aligning with frameworks like ESMAP's MTF [6], being in this way exposed to the criticalities highlighted in the previous section.They can also rely on standard parameters and wealth tiers and are usually adopted in large-scale applications [99] or expertbased methods [48].It is, furthermore, likely that a successful project pushes new residential users, additional services for the community, or new productive activities to flourish and require additional energy or appliances [32,100].To account for this phenomenon, top-down methods can investigate the correlation of improved access with explanatory variables and forecast their evolution over time [101]; -Bottom-up approaches: these approaches build the load curve by characterizing the energy behavior of every single user and summing up the effects at the community level.Tools like LoadProGen [102] and RAMP [103] or agent-based approaches [104] aim to capture households' habit variability.Such approaches require extensive input data, obtained through on-field surveys but at the same time align with the analysis of needs performed in CESP 1, the identified needs can in fact be translated into load demand curves.In order to account for load evolution or bottom-up methods, adopting surveys and hybridizing with top-down methods to validate the on-field information collected [105,106].Hybrid approaches finally investigate the mechanisms of technology diffusion, adopting, among others, System Dynamics [107].

CESP3-technical solution design
Upon assessing resource availability and local demand, the process enters its initial planning phase.The first action involves identifying suitable technical solutions, chosen based on local resource availability and their capacity to meet assessed demand.Subsequently, the second action focuses on sizing the identified solution.

Technical solution identification
As Mandelli et al [7] summarized, off-grid system (distributed or decentralized) solutions are gaining interest in DCs, where financial constraints and incomplete grid extensions persist.Various factors contribute to their appeal, spanning environmental, economic, technical, political, and social considerations.The choice of the exploited resource for energy generation (fuel-based, renewable-based, or hybrid) can influence reliability and costs [7], while the choice of the configuration of the system (stand-alone or minigrid) can have impacts on the outcomes in terms of development opportunities [108].Several tools to support the selection of an adequate technical solution are already available.These space from GIS-based tools, which optimize the achievement of a fixed tier with the economic and spatial characteristics of a population [99,109,110], to multi-criteria analysis tools [73,111,112].

Technical sizing
The sizing of off-grid systems has been performed for years on expert-based methods.More recently, even in DCs, a scientifically sound approach towards optimized solutions is offered by energy system modeling [113].
The energy system modeling optimization approach involves numerical methods, referring to the Operations Research discipline, to determine the optimal size of electricity supply, dispatch, and storage components of the system to meet a given demand.These approaches include linear programming (LP), mixed-integer linear programming (MILP), heuristic, and metaheuristic methods [114].LP constrained optimization, adopted in tools like HOMER® [115] and MicrogridsPy [106,116,117], employs linear or integer-linear constraints along with a linear objective function.This function is the overall target of the optimization and usually targets objectives like minimization of NPC or LCOE.Emerging models incorporate non-monetary, such as GHG emissions or social externalities [118].
Given the limited resources available in the African continent to be devolved to energy planning, the high cost of proprietary software can be a burden or even a limit that prevents them from being adopted.In this regard open energy modeling [63] grants free access to modeling tools, enhancing local ownership and maximizing possibility for a wide spread of capacity building activities.Energy modeling in the continent is experiencing great momentum in the last decade and has led to large communities of practice [119] and several African-led publications.

CESP4-BM design
Following the design of the technical solution, attention turns to the design of the corresponding BM.This phase involves understanding viable options in compliance with the local context (CESP1) and the technical design (CESP3).The synergy between BM selection and design, technical solution, and complementary activities ensures the project's long-term sustainability.

BM identification
Literature and case studies emphasize the relevance of a well-structured BM for energy access projects designed for continuous service provision, scalability, and long-term sustainability of the technological solutions proposed in CESP 4.
Peréz-Arriaga [71] outlines two pivotal BM characteristics: viability (successful functioning) and sustainability (self-sufficiency in the long run) and underlines the need for an effective regulatory framework to support these traits, enabling private sector involvement while upholding service quality for beneficiary communities.
From a practical point of view, Sovacool [29] compiled a comprehensive list of potential BMs for energy access projects, offering insights and potential references for BM selection, reported in table 2.

BM formulation
One of the most adopted tools for BM design is the BM Canvas [120], adapted for off-grid projects by the African Development Bank [121].Some further adaptations may also be introduced to keep into consideration the peculiar situation of those who are living at the 'base of the pyramid' .For instance, the '4As Framework' requiring Availability, Affordability, Awareness and Acceptance as reported in [92] can be considered a useful tool to check the main features of the BM in the local context.
Energy solutions for off-grid electrification may be funded through different schemes like loans, equities, grants, and subsidies depending on the technological choice and the main stakeholders involved (private like independent power producer, public or public-private partnership).A thorough view is provided in [122], where the authors also offer a practical evidence-based perspective on five potential tariffs structures (uniform, cost-reflective, bid, willing buyer, willing seller, and hybrid) designed by balancing the needs of governments, developers, and customers that may represent an updated guidelines for energy planner.

CESP5-complementary activities for long term sustainability
This phase complements CESP 3 and 4 and aims at enhancing the long term sustainability of the project through complementary activities [123].As already mentioned, energy access alone does not guarantee local development, as highlighted by the PRODUSE initiative [124].This is also confirmed by a WB report [125] which suggests four categories of complementary factors to increase the economic impact of electricity access in SSA: Enhancing access to markets, facilitating access to microcredit, building usable skills (capacity building), and improving access to public services.Based on this report, Tonini et al [123] bring evidence based on a real case field study and an associated system dynamic model that confirms that the most impacting complementary activities should: • Be identified and operate in relevant sectors for the local context (connected to CESP1).The development of complementary activities with the three above-mentioned characteristics connects this phase within the CESP cycle.Moreover, it assures that long-term sustainability encompasses the economic, environmental, and social dimensions.

CESP6-impact analysis
The final phase of CESP consists in assessing the expected impact of the energy project.Impact evaluation is a systematic and final examination of a completed project, useful to judge the overall value of an intervention and supply lessons to improve future actions.The ability of a project to monitor, review, and evaluate its impact is envisaged with the Logical Framework approach via the Result Chain (Input-Activities-Output-Outcome-Impact) [69] and it allows stakeholders to account for its success or failure.Due to the cyclical nature of CESP, it feeds back to the context analysis in CESP1 to improve future program design or to adjust the current one.
As already anticipated, energy can be seen as an 'intermediate good' , influencing a range of economic, social, and environmental outcomes through potentially long causal chains as reported by the ADB [126].In energy access, White and Raitzer [127] claim that the majority of impact analysis techniques adopted in the field tend to assume rather than verify the causal relationships between inputs and impact, often self-selecting successful results, only.To investigate the logic of these relationships, it is important to identify and formulate a specific framework of reference, such as the theory of change [128] or the same Sustainable Development Goals, which are envisaged to be transformed into real applicative standards and not to remain only theoretical approaches, as suggested by Castor et al [129] and Tenenbaum et al [42].For this reason, further investigation and testing are needed to provide energy access impact analysis with scientifically sound tools, such as the impact evaluation framework proposed in [130] or the evidence-based set of tools collected in [126].
Among the many challenges to impact evaluation, three are the most relevant: lack of quality data (or data at all); counterfactual and attributional effect.The lack of data [21] and or quality data can be today mitigated by the large data sets derived from administrative and commercial sources (i.e.: via metering system).The attribution gap and the counterfactual applied to energy projects for local development would require more high quality evidence [131] to be brought into the analysis, for instance, via empirical evidence, control trials or randomized control trials.At any rate, the space of research here is still very wide and calls for multidisciplinary approaches that can encompass different disciplines from social sciences to engineering.

Conclusions and future work
This article has proposed an innovative framework under the name of CESP, where three engineering phases are complemented by other three social sciences-based phases.Each phase has been characterized by specific tools to offer an informed decision framework for the local planner.CESP encompasses a set of techno-economic and socio-technical actions aiming at preventing potential failure, based on a counterfactual analysis used to identify the reasons behind past project failures.
The CESP framework, presenting a sequential but iterative structure that underlines the cyclic perspective of the two disciplines that it integrates, is divided into six consequential phases and constitutes a novel output.The original methodology of counterfactual analysis complements and expands traditional energy solutions planning methodologies.The CESP framework is arranged in a ready-to-use structure that emphasizes the importance of a deep context analysis, complete resource and demand assessment, and thorough design for the technical solution and the associated BMs.Complementary activities are then implemented to ensure the long-term sustainability of the project and increase its impact beyond the provision of energy per se.Each of the six phases is enriched in the final section with state-of-art tools to perform the must-have actions, taking references from various disciplines.
The research gap identified in the introduction, which called for multidisciplinary and needs-oriented standards to support energy access projects, has been addressed throughout this work.The CESP framework encourages the application and harmonization of socio-techno-economic approaches in energy access planning.
Future research in this field would benefit from continuous and systematic monitoring and review of the literature, and additional field case analysis to test the applicability of the CESP.Moreover, the possibility of investigating quantitatively the counterfactual case studies using regression analyzes, checking for causal correlations between variables (i.e. the presence or not of a certain action within a certain phase of CESP) and evidence of failure, would also provide additional evidence to revise and update the CESP to improve the success rate for energy access projects.

Figure 1 .
Figure 1.Workflow of the methodology.
claims that the program of electrification through mini-grids in Fiji failed for several reasons, among which the lack of ex-ante consultation of the local energy needs and aspirations; the counterfactual (positive) reason for this correspond to the identification of the local energy needs.This failure could have been prevented by including: needs and priorities identification.The action is therefore coded and listed in the socio-technical actions of CESP.-Brooks and Urmee [46] investigated the failure of a SHS distribution program in the Philippines.Primary issues included insufficient training for users and local technicians, resulting in the system relying on external support and ultimately leading to its abandonment.The study emphasizes the importance of addressing local gaps in skills and capacities when designing energy interventions.An associated action: local gaps identification and tackling is therefore coded and listed in the sociotechnical actions of CESP.

Figure 3 .
Figure 3. Layout of CESP, divided into techno-economic and socio-technical phases.

Table 1 .
Application of the counterfactual analysis on each case selected.Specific missing actions are associated with each case study.They are marked with if they emerged from the counterfactual analysis, and with if the counterfactual analysis confirmed actions from the state-of-art energy solution planning.

Table 2 .
Summary of viable BMs for rural electrification in DCs.