In order to launch a new policy that could improve higher contribution of private investments on renewable electricity supplied to the grid, Feed-in tariffs (FITs) program is currently aimed to substitute the previous adder program in Thailand. Increasing in renewable electricity supplied from private sector to the grid could induce higher direct and indirect effects to the economy in long run. This study provides a long-term impact assessment of the expected FIT and quantity implemented in the economy by energy input-output model. Annual expected FIT's from each renewable power sector were assessed from financial analysis and forecasted related to future costs trends. The renewable electricity contributions were forecasted as presented in the Alternative Energy Development Plan (AEDP 2012-2021) and in the Power Development Plan (PDP2010). Specific input-output structure in each additional renewable energy power sector was provided based on surveyed data. The reference scenarios were assumed that the grid electricity was performed in business as usual activity (BAU) without renewable electricity supplied. The macro economic impacts from purchasing electricity from private renewable power sector were assessed annually base on Energy Input-Output model in terms of economy-wide output, total primary energy supply (TPES), CO2 emissions, and value of employment, during the studied period. Result of the study presented a higher TPES, particularly in biomass, but a lower in fossil primary energy supply. There were increasing in significant annual CO2 emissions reductions. Both of the FITs under two different plans induced reductions in import content with some reductions in local employments due to less employments required in renewable power plants. Better impacts on FITs programs could be found in the PDP case where each renewable energy technology was supplied to the grid prioritized by minimum cost.