Feasibility analysis of power generation from landfill gas by using internal combustion engine, organic Rankine cycle and Stirling engine of pilot experiments in Thailand

In Thailand, there have recently been a few small-scale preliminary studies on power generation from landfill gas so as to assess technical feasibility prior to performance of full-scale projects. This paper presents financial analysis of those studies on electricity generation by using an Internal Combustion Engine (ICE), Organic Rankine Cycle (ORC), Stirling Engine (STE). Financial indices, such as levelized cost of electricity, net present value, internal rate of return, and payback period, are determined from actual costs of those studies to produce electricity of the power engines from landfill gas. It is found that all financial indices of ICE are mostly acceptable compared with ORC and STE, although cost of gas preparation and high maintenance in ICE are required. From investigation, this advantage of ICE is because of the highest electricity generation with compactness and wide availability in local market. In turn, the levelized costs of electricity of ICE, ORC, and STE are 0.11 USD/kWh, 0.30 USD/kWh, 0.42 USD/kWh respectively. At present, ICE might be a promising engine until costs of the imported ORC and STE decrease at feasible level of finance.