Biomass has been traditional energy source in rural Thailand for decades. Country modernization,
instead of reducing the biomass energy consumption, has continuously increased its utilization for
both households and production of modern energy. While the GDP/capita was triple during 1980–
1996, the biomass energy consumption increased by 68%, and expected to be higher as signaled by
the increasing number of new biomass power plants. The legal and financial support frameworks to
increase renewable energy utilization was launched in 1992 aiming for the country to depend less on
imported energy, which at present accounted for 7% of GDP. In this paper, biomass and biogas
energy situation in Thailand is presented. Resource potential, the promotion program and its success
and failure were analyzed to suggest new policy option recommendation. The amount of agricultural
residues is about 61 million ton a year, of which 41 million ton, which is equivalent to about 426 PJ
of energy, was unused. The most promising residues are rice husk, bagasse, oil palm residue and
rubber wood residue, merely due to their availability at the mills, which heat–power cogeneration is
feasible. Biogas resources are from industrial wastewater and live stocks manure, which have
potential of 7800 and 13,000 TJ/y, respectively. Instead of having the legal and financial support
frameworks, the success of biomass energy program in Thailand is doubtful. Discussion on
mechanisms and measures based on the past policy, which has been implemented for over a decade,
is presented. From lessons learned we propose new policy approach to, in our opinion, overcome the
biomass energy utilization barrier in Thailand.