Recently, small and medium enterprises (SMEs) are increasingly focusing on the implementation of green innovation, mainly due to customers’ increasing environmental consciousness. However, SMEs have not yet achieved any significant accomplishment. The lack of success in implementing green practices is due to various barriers. So, it is crucial to analyze and address these barriers prior to introducing green initiatives. This study prioritizes barriers and solutions to adopt green practices in the context of SMEs in Saudi Arabia. The study develops an integrated decision framework based on symmetry principles to identify main-barriers, sub-barriers, and strategies to overcome these barriers. Six main barriers, 24 sub-barriers, and 10 strategic solutions were identified through literature survey. Then, fuzzy analytical hierarchy process (FAHP) was employed to evaluate main-barriers and sub-barriers. Later, fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS) methodology was used to rank strategies. Results of FAHP revealed that the political barrier category holds higher importance than other barriers. Results of FTOPSIS showed that the strategic solution ‘developing research practices to carryout green innovation in SMEs’ is more important in addressing green innovation barriers in SMEs.

The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen, if produced efficiently, can play a pivotal role in decarbonizing the global energy systems. Therefore, this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA), with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria, including capital cost, feedstock cost, O&M cost, hydrogen production, and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally, slack-based DEA computed the efficiency of alternatives. Among the 11, three alternatives (wind electrolysis, PV electrolysis, and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.

The energy planning process essentially requires addressing diverse planning objectives, including prioritizing resources, and the estimation of environmental emissions and associated health risks. This study investigates the impacts of atmospheric pollution for Pakistan from the energy production processes under various modalities. A national-scale bottom-up energy optimization model (Pak-TIMES) with the ANSWER-TIMES framework is developed to assess the electricity generation pathways (2015–2035) and estimate GHG emissions and major air pollutants, i.e., CH4, CO, CO2, N2O, NOX, PM1, PM10, PM2.5, PMBC, PMOC, PMTSP, SO2, and VOC under five scenarios. These scenarios are: BAU (business-as-usual), RE-30 (30% renewables), RE-40 (40% renewables), Coal-30 (30% coal), and Coal-40 (40% coal). It is revealed that to reach the electricity demand of 3091 PJ in 2035, both the Coal-30 and Coal-40 scenarios shall cause maximum emissions of GHGs, i.e., 260.13 and 338.92 Mt (million tons) alongside 40.52 and 54.03 Mt emissions of PMTSP in both of the scenarios, respectively. BAU scenario emissions are estimated to be 181.5 Mt (GHGs) and 24.30 Mt (PMTSP). Minimum emissions are estimated in the RE-40 scenario with 96.01 Mt of GHGs and 11.80 Mt of PMTSP, followed by the RE-30 scenario (143.20 GHGs and 17.73 Mt PMTSP). It is, therefore, concluded that coal-based electricity generation technologies would be a major source of emission and would contribute the highest amount of air pollution. This situation necessitates harnessing renewables in the future, which will significantly mitigate public health risks from atmospheric pollution.

Tidal range energy is one of the most predictable and reliable sources of renewable energy. This study’s main aim is to determine potential sites for tidal range power in East Malaysia, by analyzing tidal range distributions and resources and the feasibility of constructing barrages. Investigation was conducted in 34 sites, estimating their potential energy outputs and studying their areas for constructing barrages. Only 18 sites were marked as appropriate for constructing a tidal range energy extraction barrage. The highest potential power was found in Tanjung Manis, and its maximum capacity was calculated as 50.7kW. The second highest potential of tidal power extraction was found in Kuching Barrage at Pending, where an energy harvester could produce electric power up to 33.1kW.

Increasing environmental concerns forced us to look for cheaper, reliable and secure sources of energy. Fossil fuels like oil, coal, and natural gas are having limited supplies and are depleting fast. Both energy security and environmental concerns have resulted in inclination towards renewable energy sources. Biodiesel does not contain petroleum, but it can be blended with petro-diesel in various mix levels. This research investigated biodiesel produced by the use of cheap waste cooking oil, collected from the local market of Nawabshah, Pakistan. The collected waste oil was converted into biodiesel by trans-esterification process at PCSIR Laboratory, Karachi. The fuel samples were tested in a diesel engine test bed unit at the Thermodynamics Laboratory of Quaid-e-Awam University. Biodiesel blends were compared with the conventional diesel fuel. The comparative analysis of the performance parameters concluded that brake specific fuel consumption of B30 (biodiesel 30%+diesel 70%) mix was 6.9% higher than that of 100% diesel. The brake thermal efficiency of B30 decreased about 4.75% in comparison with conventional diesel.