Prioritizing the Weightage of Sustainability Criteria and Sub-Criteria of Decentralized Micro-Hydropower Projects for Rural Electrification in Nepal

In many cases, sustainability of renewable energy systems (RES) is being analyzed by identifying certain criteria and sub-criteria considering equal weightage among the respective groups. However in reality, relative weightage of criteria and sub-criteria vary due to many reasons. Thus, this paper tries to prioritize the weightage of criteria and sub-criteria of decentralized micro-hydropower projects for rural electrification by analyzing sustainability indicators related to four dimensionstechnical, social, economic, and environmental. An Analytical Hierarchy Process –Online Software (AHP-OS) model is used to prioritize the weightage of respective criteria and subcriteria through expert opinion. Suitable goal, criteria and sub-criteria are developed after reviewing pertinent literature and consultation of the experts. The results reveal that technical criteria (0.362) is the most crucial sustainability criteria followed by economic (0.290) and social (0.226). Environmental criteria (0.122) is found to be the least preferred criteria. The results reveal that ‘energy availability’ (10.8%) is observed to be the most preferred and ‘GSI inclusion’ (2.4%) is ranked to be the least preferred sub-criteria among the 19 sub-criteria. Nepal, being a developing country, shows a trend of people preferring the development of energy services first at a relatively low cost without considering the environment and gender/social inclusion. As a result, technical and economic criteria and sub-criteria are preferred more than that of environmental and social. The outcome of the research can help decision-makers and policy-makers in shaping energy policies, plans, and programs, and foster future pathways for providing sustainable rural electrification in the country.

decision-support framework, and step-to-step process of Analytical Hierarchy Process (AHP) method for decision making process. Section-3 and 4 highlight the results of empirical analysis and discussion based on local stakeholders'/experts' preference in prioritizing sustainability criteria and sub-criteria of existing microhydropower projects in Nepalese context. Finally, Section-5 concludes the study specifying the main outcomes of the study. Sustainability of Energy System: Brundtland et al. (1987) defined -"Sustainable development is development that meets the needs of the present without compromising the ability to future generations to meet their needs". The United Nations has endorsed to implement global initiatives-Sustainable Development Goals (SDGs) i.e. decision made by the UN Conference on Sustainable Development held in Rio de Janeiro in June 2012 and the UN General Assemblies held in September 2014 and 2015 (NPC 2017). Most of the countries including Nepal, have already committed to implement the SDGs. The SDG-7 aims to "ensure access to affordable, reliable, sustainable and modern energy for all" as one of 17 goals for 2030 (ESMAP 2017). Nepal, being a member state of the United Nations, is committed to these global initiatives. Besides meeting the global and national commitments, the sustainable development of energy system is being increasingly more important for policymakers and decision-makers worldwide (Santoyo-Castelazo & Azapagic 2014). Meeting the sustainability of energy systems, it requires consideration and integration of four main sustainability aspects of energy system: technical, social, economic, and environmental. This aspect is progressively being adapted by policy-makers and decision-makers and is reveled in many studies that have considered the sustainability of energy systems mainly in electrification rather than heating (Santoyo-Castelazo & Azapagic 2014;Ciroth et al. 2011).
Micro-hydropower project as a Decentralized Electrification: Micro-Hydropower Project (MHP) is a matured technology for decentralized electrification solution in Nepal. Mainly hills and mountain regions of the country is preferably suitable for MHP due to abundantly available water resources, potential head and unavailability of grid-electricity. As per experts' survey carried out by Thapa et al. (2019) micro-hydropower is one of the most preferred decentralized rural electrification solution in Nepal. It is a mini-grid solution working as an isolated manner with relatively low generation (1 -100 kW), low-voltage distribution grid (400 V or 11 kV) that provides electricity to a community, village or a small town (UNDP 2014). It is one of the mature technologies in Nepal. Though electrification from hydropower was initiated during 1960s, development of decentralized hydropower was mainstreamed only after establishment of AEPC in 1996 (WB 2015). Similarly, runoff river types of projects are designed considering 11-month flow exceedance to ensure designed power be available at least 92 percentage of time in a year (AEPC 2008; AEPC 2014).
As per AEPC database more than 1800 MHPs are operating and about 100 MHPs are in under construction stage (AEPC 2018). And these MHPs are wide spread in the country especially in hilly areas covering 55 districts out of 77 districts (AEPC 2018). Districts in plain areas are not suitable for MHP due to lack of available head. Moreover, most of these districts are covered by the national grid. MHPs are providing energy for lighting, running small and medium size enterprises, and ensuring electricity to social services especially in the rural parts of the country.

Models and Methodology 2.1. Establishing Decision-Support Framework
The decision-support framework for determining local experts' preference on weightage of selected sustainability criteria (dimension) and sub-criteria (indicators) of decentralized electrification system is outlined in Figure 1. The selected decision-support framework involves the following procedures: 1. Selection of suitable tool-Analytical Hierarchy Process-Online Software (AHP-OS) as a multi-criteria decision making (MCDM) tool; 2. Selection of indicators for assessing sustainability of energy system; 3. Categorization of indicators in four-dimensions: technical, social, economic & environmental; 4. Integration of sustainability dimensions and indicators via a multi-criteria decision analysis (AHP method) to determine the relative and global weightage of sustainability dimensions and indicators that determine the most suitable option for the future path.
the relative importance of the elements in the second level with respect to the overall objective of the first level. The scale for entering judgments is given in Table 1 Additional comparison matrices are used to compare the elements of the third level with respect to the appropriate parents in the second level and so on down the hierarchy T. L. Saaty 1986). The synthesis of priority principle stands for synthesizing the priorities from the second level down by multiplying local priorities by the priority of the corresponding criterion in the level above and adding them for each element in a level according to the criteria it affects. This gives the composite or global priority of that element T. L. Saaty 1986).
One of the characteristics of the AHP is that it provides a model for decision-making, ranking and prioritizing the problem that is flexible in a user-friendly manner. Comparison values can be acquired from surveys or measurement from the respondents using fundamental scales. For prioritizing sustainability criteria and subcriteria (indicators) of decentralized micro-hydropower projects in Nepal, AHP applied in the following five steps (Brent & Rogers 2010;Thapa et.al. 2019;T. L. Saaty 1994).
Step 1: Problem hierarchy: The research goal (prioritizing sustainability criteria and sub-criteria of installed micro-hydropower projects in Nepal) is located at the top-level. At the second level, themes/criteria are located which are further divided into sub-criteria according to the level of detail required. The criteria/sub-criteria is defined as a set of attributes that allow the decision makers to set preferences. All the solution-alternatives are placed at the bottom of the hierarchy in order to a make final decision T. L. Saaty 1994).
The four sustainability dimensions/criteria that are considered to analyze sustainability indicators of installed MHPs for rural electrification in Nepal is: technical, social, economic, and environmental. And various 19 subcriterion/indicators are considered within each of the four dimensions to measure/compare the sustainability of installed MHPs. Based on the AHP model, the hierarchical structures is shown in Figure 1. Step 2: Set of priorities for criteria and sub-criteria: According to the preference of the decision makers, a numerical value shall be assigned to each criterion and subcriterion. As per Saaty, the nine-scale is proposed for assigning numerical value as per Table 1 In case of setting priorities for sub-criteria, a paired comparisons is formulated for establishing importance of the sub-criteria with respect to a higher level (T. L. Saaty 1986 ; T. L. Saaty & Vargas 2012). In the case of setting priorities for criteria, a paired comparisons is formulated for establishing preferences of the criteria with respect to higher levels i.e. goal of hierarchy structure (T. L. Saaty 1986  Moderate importance of one over another Experience and judgment slightly favor one activity over another 5 Strong importance Experience and judgment strongly favor one activity over another 7 Very strong importance Activity is strongly favored and its dominance is demonstrated in practice. 9 Extreme importance The evidence favoring one activity over another is of the highest possible order of affirmation 2,4,6,8 Intermediate values between two adjacent judgments When compromise is needed Reciprocal of above If activity i has one of the above non-zero numbers assigned to it when compared with activity j, then j has the reciprocal value when compared with i. Source: (T. L. Saaty 1986) Step 3: Formulation of pair-wise questionnaires: Based on nine-point scale, a pairwise comparison is formulated for criteria and sub-criteria with respect to the higher level in order to acquire judgment from the experts (R. W. Saaty 1987).
Step 4: Define global weight for criteria and sub-criteria: Global weight for the criteria and sub-criteria (indicators) is obtained from the multiplication of the local or relative weight (wi) by the global weight of the immediately superior criterion. The sum of the global weights of the alternatives in relation to each criterion is the mechanism to obtain the prioritizing weightage of sustainability of all possible criteria and sub-criteria. The weights of each alternative within them are computed using: = × ….... (1) Where, A is the comparison matrix of size n x n for n criteria. It is also called the priority matrix and w is the Eigenvector of size n x 1, also called the priority vector, which is the weight. ʎmax is the maximum Eigenvalue (T. L. Saaty 1994). Eigenvector and priority vector could be obtained by solving for the principle Eigenvector. Though there are many means to solve the priority vector, an easy way to get an approximation of the priorities is to normalize the geometric means of the rows (R. W. Saaty 1987).
Step 5: Verify the consistency of the judgments: Finally, the consistency index is used to measure the degree of consistency of the estimation. The consistency index (CI) is calculated by: = ….... (2) In order to verify the CI values, a comparison is made with the random consistency index (RI). This parameter is defined as an average of the CIs of the large set of matrices with random inputs (T. L. Saaty & Vargas 2012). In addition, Saaty defines the consistency ratio (CR) = CI/RI. If CR ≤ 0.1, the results are consistent. If CR>0.1, the data are inconsistent and the decision makers' judgments need to be reviewed.  Zen et al. (2016) points out that measuring sustainability is a major challenge and a key issue for discussion on sustainable development. Developing a reliable tool to measure sustainability is a pre-requisite for policy-makers and decision-makers to distinguish whether they are fostering sustainable development or should be re-adjusted (Zen et al. 2016). Therefore establishing reliable and measurable sustainability criteria and sub-criteria is important that needs to be continuously monitored. Establishing sustainability criteria and sub-criteria: Traditionally technical and economic criteria were considered in decision making that could not be coherent with the development of electric system based on the developmental conditions and protection of local environment. Due to this, social and environmental considerations were poorly explored though these factors would contribute to robustness in sustainable decentralized energy (Rojas-Zerpa & Yusta 2015). Therefore, technical, economic, Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.9, No.9, 2019 social and environmental criteria are considered to implement in the study. Different literature related to problems of energy planning, implementation, evaluation etc. using multi-criteria decision making (MCDM) tools are reviewed in order to establish the criteria and sub-criteria. Then, consulting with experts from academic, private sector, public sectors and non-governmental organizations, the final sub-criteria are established. In such a way, a list of 19 sub-criteria are prepared and then are grouped into four criterion: technical, social, economic and environmental. Then after, selected sub-criteria are clustered in four criteria. The final criteria and sub-criteria with description are shown in the following Table 3.

Social
Social sustainability focuses on the equitable distribution of benefits offered by and social acceptance of electrification that can be captured by enabling the technological intervention in the fundamental social services e.g. health, education, agriculture, communication & information and contributing to poverty reduction by fostering income generation opportunities to the locals so that everyone irrespective of any economic, social or gender disparity can make the use of service. Accessibility Accessibility is the proportion of households in the catchment area that has access to electricity. The ratio of household income spent on fuels and electricity to the total household income. It also refers to users' perception of electricity prices.

Description of Indicators (Units) References
Access to social services (Social benefits) The capacity of the system to supply energy in schools and health posts or energy access to social services [e.g. health, education, public buildings, information-communicationtechnology, agriculture facility]

Economic
A project is economically sustainable if its revenue suffices for smooth operation to provide electricity services to its clients and it can manage repair and maintenance till its lifespan.

Per unit investment cost
It refers to the per unit initial investment cost of energy system (US$/kW). Investment cost consists of total expenses occurred while establishing the system e.g. equipment, construction, labor, infrastructure, installation and commissioning costs.

Environmental
Environmental sustainability aims to reduce the local and global impact in the environment by contributing to minimizing the negative impacts of energy solution on the environment. It focuses on the adaptation of national regulation, civil society's awareness on environmental issues.

Environmental Awareness
Awareness is the consciousness of society about the environment. It is the level of awareness during the planning, construction and operation phase.   (2019) Comparing the relative weightages (refer Table 4) 'technical criteria', with priority weight 0.362, is appeared to be the most crucial criteria in the determination of sustainability of decentralized electrification system. 'Economic criteria' (0.290) is found to be the second crucial criteria followed by 'social criteria' (0.226). 'Environmental criteria' (122) is appeared with the least significance in the Nepalese context. Similar results were observed from the past studies, for instance a study carried out by Dhital et al. (2018); Lee & Chang, (2018), 'technical and economic criteria' are mostly prioritized whereas environment and social are found to be least preferred criteria for sustainability of renewable energy systems in Nepal and Taiwan respectively. However, in case of Turkey and Algeria 'environmental criteria' is found to be the most preferred from sustainability perspectives (Demirtas 2013;Haddad et al. 2017;Çolak & Kaya 2017;Stojanovic 2013).
Similarly, looking into the relative weightage of sub-criteria under "technical criteria", 'energy availability' (0.289) is found to be the most crucial sub-criteria (indicator) followed by 'reliability' (0.253) whereas 'skillavailability' (0.101) is ranked to be the least prioritized indicator. In case of social criteria, 'affordability' (0.267) followed by 'accessibility' (0.208) become the most prioritized indicator and 'GSI inclusion' (0.108) is appeared to be the least preferred indicator from the experts.
Similarly, in case of economic criteria, 'unit investment cost' (0.310) is found to be the most crucial indicator followed by 'O&M cost' and 'project benefit' and 'contribution to users' (0.167) income' is ranked to be the least prioritized indicator. Similar result is seen with 'investment' and 'O&M cost' being the most crucial in the study carried out by (Demirtas 2013).
Likewise in environmental criteria, 'environmental awareness' (0.351) is ranked as the most prioritized indicator followed by potential of 'greenhouse gas avoided' whereas 'loss of land use' (0.202) appeared to be the least prioritized indicator from the experts.

Aggregation of sustainability dimensions based on experts' preferences
In order to see any variation in preference on four-dimensions based on five stakeholders' group were computed, which is illustrated in the following Figure 2.  (Figure 2), the local experts think that technical (36%) is mostly preferred criteria followed by economic (29%) and social (23%). Whereas, environment (12%) is least preferred criteria from local stakeholders' view. But, looking into individual preference from different stakeholders, it shows both convergence and divergence of preference among the groups. For instant, experts from development partners & INGO group consider that economic (34%) dimension is the crucial criteria for sustainability of energy systems in contrast to rest of the groups and private sector thinks that economic (30%) and technical (31%) have similar role in contribution to sustainability of energy system. Referring the past studies, for instance studies carried out by Rojas-Zerpa & Yusta (2015), the result is found to be more divergent. The academician preferred social criteria to be most preferred whereas, private sector preferred economic to be the most crucial criteria. Similarly, government (regulators) preferred environmental and NGO/developer (communities) preferred technical criteria to be the most crucial for sustainability of electric systems (Rojas-Zerpa & Yusta 2015). As per them, the preference on the selected criteria may vary based on the background of the experts and they have suggested to incorporate relatively higher numbers of stakeholders' involvement in decision-making process that ensures participation, reality, transparency and legitimacy. However, in this case, there is not significance difference in mean value of weightage among the stakeholders group as per ANOVA test (ranges from F4, 86 = 0.257, p > 0.05 to F4, 86 = 1.174, p > 0.05). Therefore, it can be concluded that, the group results is converged to overall result, which implies that technical criteria is the most crucial for sustainability of energy system in Nepal followed by economic, social and environmental criteria.

Experts' preferences on sub-criteria in consolidated form
Similarly, consolidated (normalized) global priorities of 19-indicators (sub-criteria) is calculated and presented in the following Figure 3 www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.9, No.9, 2019 Figure 3: Consolidated global priorities of sub-criteria from experts' input Figure 3 provides the spider diagram illustrating the weightage of sub-criteria (indicators), where the star at the core of the web represents the least priority weightage and star at the farthest outmost surface of the web represents the highest priority weightage. The results reveal that 'energy availability', 'reliability' and 'unit investment cost' are the most prioritized indicators. This points out the fact that renewable energy sources with high potential for 'energy availability', and 'reliability' and lower potential of 'unit investment cost' are the key indicators for sustainable energy generation projects. Likewise 'O&M cost', 'project benefit', 'efficiency' and 'affordability' are also found to be major indicators from sustainability perspectives. It refers that concern stakeholders should take care of these indicators while addressing sustainability of off-grid technologies for rural electrification. 'Gender and social inclusion', 'household air pollution', 'loss of land use', 'access to social services', and 'local job creation' are found to be least prioritized indicators from the perspective of sustainability. Rest of the indicators -'plant factor', 'contribution to users' income', 'accessibility', 'environmental awareness', 'social acceptance', 'skill-availability' and 'greenhouse gas avoided' are seen as moderately prioritized by the experts.
In order to see if there is any discrepancy in preference on the selected sub-criteria based on five stakeholders' group, preferences were computed varying with those groups and presented in the following Figure 4.  Figure 4 shows that there is both convergence as well as divergence of preferences among the five different stakeholders/experts groups. In general, we can observe convergence of preference on the most of the cases. In case of 'energy availability' and 'unit investment cost', besides private sector all four-groups have put the highest preference. Similarly, in case of 'efficiency', 'reliability', 'affordability', 'social acceptance', 'GSI inclusion' all the group result is converged. However, divergence cases are also seen in the figure. For instant, NGO & Developer gave more preference on 'accessibility' and least 'preference on 'O&M cost', 'project benefit' and 'contribution to users' income' in contrast to other group. Likewise, DP&INGO think that 'project benefit' has more potential and 'GHG avoided' has less potential in contribution to sustainability of energy system. Similarly, private sector perceive that 'access to social service', 'local job creation' and 'loss of land use' has a bit higher role for sustainable operation of energy services.
However, ANOVA test performed among sub-criteria (indicators) and sector-wise responses signifies that there is not significance difference in mean value of each sub-criteria weightage among the stakeholders' group (which ranges from F4, 86 = 0.502, p > 0.05 to F4, 86 = 2.255, p > 0.05). Therefore, it can be concluded that the mean priority weightage of each sub-criteria and criteria among the five stakeholders' group is same as aggregate figure (consolidated global priority).
Moreover, AHP group consensus is found to be 70%, which is moderate consensus according to the definition by Dr. Klaus (Goepel 2018). It means aggregate consensus from the group members (91 respondents) is estimated to be 70% which implies that the result of global priorities are moderately homogeneous in the research. Overall consistency ratio is found to be 0.45% and individual consistency ratio is 10% or less. Thus, the model of prioritizing the sustainability criteria and sub-criteria from the expert opinion is validated.
The limitation of the study is exclusion of institutional and political dimensions which are also key criteria for sustainability of rural electrification. Moreover, the study is entirely relying on experts' opinion. Therefore, future research is necessary to validate it based on project specific information.

Discussion
Based on the assessment result, some general remarks are drawn regarding the selected assessment framework, criteria and sub-criteria (renewable energy systems). Looking the stakeholders'/experts preference on the selected criteria (sustainability dimension), technical (0.362) is mostly prioritized followed by economic (0.290) and social (0.226). Environment (122) is least preferred criteria for sustainability of decentralized micro-hydropower in Nepalese contexts. The results have come together with the outcomes from previous studies carried for developing countries (Dhital et al. 2018;Lee & Chang 2018); whereas it is diverted in case of developed countries (Demirtas 2013;Haddad et al. 2017;Çolak & Kaya 2017;Stojanovic 2013). The behavior of the results implies that preference of sustainability criteria vary from country to country based on its resource availability and technological maturity. While comparing the priority of sustainability dimensions, environmental criteria seems to be most concern matters in relatively developed countries, whereas technical and economic criteria are preferred in the relatively developing countries.
Local stakeholders/experts, in general, (Figure 3) expressed high preference for 'Energy availability', 'unit investment cost', O&M cost, 'project benefit 'reliability', and low preference on 'GHG emission avoided', 'loss of land use', 'HHs air pollution avoidance', 'GSI inclusion', which implies that preference is focused relatively on local benefit rather than regional and global benefits. However, in some cases preferences are diverged, if we compare the judgement based on individual stakeholders groups ( Figure 4). But, statistical test suggests that there is no significance difference in mean value of judgement among the stakeholder group.
As discussed above, people from developed world take care more about the environment and social issues while developing a project, whereas people from developing world prefer technical and financial issues rather than environment and social issues. As Nepal is a developing country, people preferred the development of energy systems first with relatively low cost without considering the environment and gender/social inclusion. As a result, technical and economic criteria/sub-criteria are preferred more compared with environmental and social criteria/sub-criteria.
The result implies that the MCDM assessment framework can be useful for evaluation of current as well as future renewable energy systems including micro-hydropower projects at local level by incorporating local experts'/stakeholders' preferences in the process. Involvement of local stakeholders enhances legitimacy, transparency (Braune et al. 2009) and ownership in the framework and a result it helps to ensure consensus on the outcomes and also creates conducive environment for improvement on policies, plans and procedures.

Conclusion
As per stakeholders' judgements, technical criteria is observed to be the most crucial criteria for sustainability of decentralized rural electrification with highest priority weight followed by economic and social criteria. Environmental criteria is found to be the least preferred sustainability criteria. Comparing the consolidated (normalized) global priorities of sub-criteria, 'energy availability' is observed to the most preferred and GSI Journal of Energy Technologies and Policy www.iiste.org ISSN 2224-3232 (Paper) ISSN 2225-0573 (Online) Vol.9, No.9, 2019 inclusion is ranked to be the least preferred indicator among the 19 sub-criteria. Similarly, 'reliability and 'unit investment cost' are also seen as crucial sub-criteria that need to be properly considered while addressing future pathways of decentralized rural electrification in Nepal. As Nepal is a developing country, people prefer the development of energy systems first at relatively low cost without considering the environment and gender inclusion. As a result, technical and economic criteria / sub-criteria are preferred more than environmental and social.
Therefore, it can be concluded that the proposed 'MCDM assessment framework' based on AHP-OS model enables a basis for prioritizing the criteria and sub-criteria for analyzing sustainability assessment of energy system; providing an effective decision making tool in rural electrification and development field.
The outcome of the research will help decision-makers and policy-makers in shaping energy policies, plans and programs, and foster future pathways for providing sustainable rural electrification in the country. Similarly, relevant stakeholders will be benefited to improve their priorities in proper aspects of products and services in the future.