Taiwan is a country highly dependent on imported energy, but it possesses abundant bamboo residue resources; therefore, it is important and necessary to make the best use of those resources to develop technologies to convert residues into biomass energy. The purpose of this study was to evaluate the costs and benefits of two investment plans for an updraft gasification power generation system using bamboo residues in the Zhushan area, Nantou County, central Taiwan. According to the annual amount of bamboo residue from an individual bamboo processing company and from most bamboo processing industries in the Zhushan region, this study investigated 2 investment plans of gasification power generation: a single plant and a regional plant. The evaluation results showed that the singleplant investment plan, with an operating time of 1,000 h yr-1, power generation of 80,000 kWh yr-1, and bamboo residue consumption of 300 tons yr-1, could create an operating benefit of around NT$1,354,000 yr-1 (the exchange rate in 2019 was US$1≈New Taiwan (NT)$31.09), but the operation still exhibited a financial loss after deducting necessary costs. The net present value (NPV) calculated for an operation period of 15 yr was -NT$4,497,588 with an internal rate of return of -2.26% and a required payback period of more than 59 yr. The regional-plant investment plan, under an operating time 5600 h yr-1, power generation of 2,240,000 kWh yr-1, and bamboo residue consumption of 8,400 tons yr-1, created an operating benefit of around NT$35,482,000 yr-1. The NPV of this investment plan calculated over 15 yr was NT$107,663,898 with an internal rate of return of 26.54%, and only 5 yr was required to recover the initial investment costs. In comparison, the regional-plant investment plan of gasification power generation would be a more-feasible and better choice for investors because of larger-scale advantages and relatively greater profits.