In current times, energy is of vital importance to ensure the economic and social development of countries. In this regard, energy security is an important aspect of the energy sector. This paper analyses the benefits and costs which accrue for various policy options for the Thai power sector. The policies which are considered in this paper include i) low carbon society (LCS), ii) introduction of nuclear power plants, iii) integrated resource planning (IRP) and iv) combination of these measures. The case study of Thailand has been modeled using a bottom-up integer programming based optimization model called 'Model for Energy Supply Strategy Alternatives and their General Environmental Impacts' (MESSAGE). In this study, Thailand has been modeled as a single region with seven scenarios including the Reference scenario. Energy security has been assessed along the themes of oil security, gas security, and sustainability. Results show that in terms of cost savings and improving energy security along the theme of sustainability the LCS and Combined scenarios are the most effective measures. Another important result is that none of the policy measures have significant impacts on oil security in Thailand. © 2011 IEEE.