A Multi Criteria Approach to Rank Renewable Energy Technologies for Domestic Sector Electricity Demand of Pakistan

Renewable technologies could be utilized to solve the energy crises of world’s sixth most populous country, Pakistan. Being rich in renewable resources of energy, the demand of electricity in household sector of Pakistan can easily be fulfilled which is otherwise scarce and have made the life of common people highly miserable. To formulate proper policies concerning the development of alternate energy sector it is essential to evaluate and prioritize the renewable technologies. In the present paper the aforementioned issue of evaluation and prioritization of renewable technologies has been addressed using AHP (Analytical Hierarchy Process) with the aim that the financial, technical, societal and environmental aspects are not compromised. Six alternatives (namely solar, wind, biomass, geothermal, ocean and hydel energies) have been prioritized.  It has been concluded that to get around the crises of domestic electricity shortfall the choice of solar energy technology is the best among the alternatives highlighted above, followed by wind and biomass. With reference priority of the choice of alternate energy it is also emphasized that the financial aspect must be the decisive factor.


Solar Energy
Pakistan has a huge potential of solar energy [9]. Pakistan receives sun shine more the 300 days/year. In various parts of the country the sun shine hours are around 7-8 hours/day [10]. Pakistan is situated in an area of highest solar average insolation in the world. Solar insolation of as high as 5-7KW h/m 2 are mapped in Pakistan [11]. At present various solar projects are in development phase under AEDB.

Wind Energy
In 2016 the installed electricity generation capacity from wind power increase by 12.5% compared to 2015 globally [12]. Our

Hydro Energy
Pakistan has an estimated hydel power potential of 60,000 MW. Pakistan has an installed capacity of about 6720 MW of hydro power [16]. There is a lot of potential of hydroelectricity generation which could be explored if suitable policy and projects are implemented keeping aside false arguments. Micro hydel projects are considered a good approach to electrify rural households [17].

Biomass
Pakistan is an agriculture country. Biomass is an energy resource for Pakistan. Crops residues and animal dung are the biomass produced from agriculture and livestock [9]. Dispose of Municipal solid waste is a big issue faced by large cities in Pakistan, use of this waste to generate electricity could contribute to house hold sector electricity crisis. In villages waste from agriculture sector and livestock could be used to generate electricity.

Ocean Energy
Tidal power has an advantage on the other renewable resources as it is almost perfectly estimated for long time [18]. The coastal line of Pakistan extends about 1000 km with complex network of creeks in the Indus Delta region.
The creek system of Indus Delta range over an area of 190 km 2 [19]. Tidal power of Pakistan is not yet estimated and exploited. It could be a great potential source of energy to fulfill future energy needs of the country.

Geothermal Energy
The potential of geothermal energy for Pakistan has not been evaluated and exploited yet. It is present in the form of Hydro thermal resource and hot dry rocks. HVAC (Heating, Ventilation and Air Conditioning) and process heat are the major consumption unit of domestic sector and shallow geo thermal energy can provide the demand effectively [20].

Analytical Hierarchy Process
One of the methods used for MCDM is AHP. AHP is extensively used in energy planning as well as resource management. AHP was originally developed by Saaty.
The working steps for this method are: (i) Description of objectives into a hierarchical model.
(ii) Determination of weights for each criterion.
(iii) Calculating priorities of each alternative in the view of criteria.
The model has following strength (i) It is adaptable.
(ii) It is simple and complex mathematics is not involved. sub-criteria. The study results show that solar is the best suitable energy technology for Algeria [28]. The classification of renewable energy alternative is done for the state of Crete using multi-criteria method [29].
The evaluation of the potential of offshore wind energy was done using AHP for Taiwan [30].

Methodological Approach
To evaluate Renewable Energy Technologies for Pakistan a research approach has been designed with the formulation of AHP model and evaluation of expert's feedback. Ten energy experts were selected with expertise in renewable energy and energy policy. The experts belong to both academic and industrial sector.
Experts were informed about the objective of the study.
The judgement from the experts were collected through face to face interviews. The experts were asked to give their judgement on pairwise comparison of criteria that aim to provide the vector of weights that represent the priority each expert assigned to each criterion. In the next step the experts were requested to assign the priority regarding the performance of alternatives with respect to each criterion to generate normalize matrix of options.
The final ranking of renewable energy technologies is done by combining the vector of weight of criteria and normalize matrix of options. The pair wise comparison was done according to preference scale shown in Fig. 2.
Following are the sequential steps followed by the study: The AHP method is applied in an excel file for the computation of scores, consistency checking and ranking of alternatives.

ANALYSIS OF DATA AND RESULTS
The priority weights for the indexes are calculated by formulating a paired matrix. The composite weights of each renewable technology are calculated. The ranking of renewable technologies was done according to weights. The AHP process was applied and following criteria weights are obtained as shown in Table 1.  Table 3 resources of other regional countries as well.