Taiwan imports more than 99% of her energy and suffers from climate change effects such as rising ocean level. Therefore, energy insecurity and GHG emissions offset are two serious problems facing Taiwan. This paper examines the possibilities for domestic bioenergy production in Taiwan utilizing set-aside land. Three bioenergy alternatives are examined: Pyrolysis-based bioelectricity, conventional bioelectricity and ethanol. We examine the comparative economics and choices among these alternatives under current Taiwanese agricultural system policies and also under altered energy and greenhouse gas/carbon prices. Biochar, produced from pyrolysis, is also investigated for different uses: whether it is best used as an energy source and/or a soil amendment. The study employs modified Taiwanese Agricultural Sector Model (TASM) to simulate the effects of the alternatives in the face of energy and greenhouse gases prices. Results show that ethanol production is chosen under current conditions but that this is replaced by pyrolysis-based bioelectricity when the GHG price is high. The results also indicate that Taiwan's energy security can be enhanced by domestic bioenergy production and up to1.59% of total GHG emissions can be offset.