ارزیابی راه‌کارهای بهبود عملکرد زیست‌محیطی نیروگاه‌های مبتنی‌بر سوخت فسیلی در چارچوب تصمیم‌گیری چندشاخصه

Objective: Power generation plants are major drivers of urbanization, economic growth, and commercial development. However, they also contribute significantly to environmental degradation, particularly through their role in global warming and climate change. Mitigating the adverse environmental impacts associated with the operation of fossil fuel-based power plants is therefore an essential step toward protecting vital natural resources. Accordingly, the present study aims to evaluate alternative mitigation strategies and identify the most appropriate option for reducing the adverse environmental impacts of combined-cycle power plants within a multi-criteria decision-making (MCDM) framework.
Method: First, a panel of experts specializing in energy and environmental sciences was established to identify context-specific alternatives and relevant evaluation criteria based on regional conditions. The Best–Worst Method (BWM) was employed to determine the relative weights of the evaluation criteria, while the Vlse Kriterijumska Optimizacija I Kompromisno Resenje (VIKOR) method was applied to prioritize the alternatives for mitigating environmental hazards.
Results: The BWM results indicated that the criterion of impact on greenhouse gas emission reduction was the most important evaluation criterion, with a weight of 0.50. The VIKOR analysis further demonstrated that the implementation of an intelligent environmental monitoring system at combined-cycle power plants ranked first among the evaluated alternatives, achieving a VIKOR index of 0.
Conclusion: The proposed integrated decision-making framework provides a systematic approach for identifying effective strategies to mitigate the environmental impacts of combined-cycle power plants. Given its flexible structure and reliance on expert-based multi-criteria evaluation, the framework can potentially be extended to other types of power plants. Its application can support the selection of comprehensive mitigation strategies capable of delivering both economic and environmental benefits over the medium and long term.
 
Extracted Abstracted
Introduction
Electricity is essential for modern societies, economic development, and technological advancement. Although renewable energy is expanding, fossil fuels remain important for electricity generation and contribute to greenhouse gas emissions, air pollution, and water consumption. These impacts are particularly significant in water-stressed regions.
Combined-cycle power plants are generally more efficient than conventional gas-fired plants but still require substantial water for steam generation and cooling. Therefore, improving their environmental performance requires considering emissions, water use, economic costs, and technical feasibility simultaneously.
Multi-Criteria Decision-Making (MCDM) methods provide a suitable framework for such problems. The Best–Worst Method (BWM) determines the relative importance of evaluation criteria with fewer comparisons, while the VIKOR method ranks alternatives by identifying the best compromise solution. This study applies a BWM–VIKOR framework to prioritize environmental mitigation strategies for the Qom Combined-Cycle Power Plant in Qom Province, Iran.
 
Method

i. Study Area and Case Study

The Qom Combined-Cycle Power Plant is located in Qom Province, Iran, and consists of four gas units and two steam units. Natural gas is its primary fuel. The region has an arid climate and limited water resources, making both emissions and water consumption important environmental concerns.
 

ii. Alternatives and Evaluation Criteria

Experts in energy policy and environmental sciences identified three mitigation alternatives:

Low-emission burners
Water recycling combined with treated municipal wastewater
Smart environmental monitoring system

Five criteria were considered: investment cost, operation and maintenance cost, greenhouse gas emission reduction, water savings, and implementation and operational effectiveness.
 

iii. Best–Worst Method

BWM was used to determine the weights of the five criteria. Experts identified greenhouse gas emission reduction as the most important criterion and operation and maintenance cost as the least important. The resulting comparisons were used to calculate the optimal criterion weights.
 

iv. VIKOR Method

VIKOR was applied to rank the three alternatives using the BWM-derived criterion weights. The expert assessment matrix was normalized and weighted, and the VIKOR index was calculated. A lower VIKOR value indicates a more preferable compromise solution.
 
Results

BWM Results

Greenhouse gas emission reduction was the most important criterion, with a weight of 0.50, followed by water consumption at 0.21. Investment cost, implementation and operational effectiveness, and operation and maintenance cost received weights of 0.12, 0.10, and 0.04, respectively.
These results show that environmental factors, particularly emissions and water consumption, were considered substantially more important than direct operating costs.
 

VIKOR Results

The smart environmental monitoring system ranked first with a VIKOR index of 0.000. The low-emission burner ranked second with 0.223, while the water-recycling and treated-wastewater system ranked third with 1.000.
The monitoring system achieved the best overall compromise because it can support continuous monitoring of emissions, water consumption, wastewater quality, and environmental compliance. Although low-emission burners provide important emission reductions, their overall performance across all criteria was lower. The water-recycling alternative, despite its importance in a water-stressed region, performed less favorably when economic, environmental, and technical criteria were considered together.
 
Conclusion
This study developed a BWM–VIKOR framework to prioritize environmental improvement strategies for the Qom Combined-Cycle Power Plant. The BWM results identified greenhouse gas emission reduction as the most important criterion (0.50), followed by water consumption (0.21).
The VIKOR analysis ranked the smart environmental monitoring system first (0.000), followed by low-emission burners (0.223) and water recycling with treated municipal wastewater (1.000).
Overall, the findings indicate that smart environmental monitoring provides the most balanced strategy for improving environmental management, supporting regulatory compliance, and monitoring emissions and water use. The BWM–VIKOR framework can also be adapted to other combined-cycle and fossil-fuel power plants by incorporating their specific environmental, economic, and technical conditions.