การประเมินทางเศรษฐศาสตร์สิ่งแวดล้อมในการนำซากมูลฝอยเก่า จากบ่อฝังกลบแบบถูกหลักสุขาภิบาลมาผลิตเป็นพลังงานมูลฝอย ในพื้นที่จังหวัดสงขลาและจังหวัดพัทลุง

Abstract

This research aimed to assess the energy generation from Refuses Derived Fuel of sanitary landfills in Songkhla and Phatthalung provinces by using environmental economic method. All externalities were taken into consideration to be screened and then evaluated. The information from the study can be used in making decision on solid waste disposal in municipalities, especially in Songkhla and Phatthalung provinces.

The research found out that solid waste put in landfill about seven years or more is the most suitable period for using in the Refuses Derived Fuel. When external costs and benefit were incorporated, the present value of total cost and total benefit of incineration plant with capacity of 250 ton/day and 20 years life was 2.55 thousand million bath and 3.80 thousand million bath respectively. NPV at a discount rate of 12 percent, using the project life of 20 years, was 1.24 thousand million baht which was positive and BCR was 1.49, meaning that the project was economically viable. Sensitivity analysis when external costs were not incorporated showed that the project was not economically viable and when external costs were incorporated the result showed that NPV was positive in all cases except in the cases of 20% increased cost and 20% reduced benefit. Songkhla City Municipality should consider the incineration plant that can generate energy from Refuses Derived Fuel. Although to do so may require high expenses, but when comparing with social benefits, it is found that the intangible benefits covered the costs.